path: root/docs/PROTOCOL.md

# The Hotline Network Protocol – Version 1.9

**Property of Hotsprings Inc.**
Publicly licensed under the GPL

---

## Table of Contents

- [Protocol Overview](#protocol-overview)
- [Session Initialization](#session-initialization)
- [Transactions](#transactions)
- [Transaction Types](#transaction-types-with-type-id)
- [Transaction Descriptions](#transaction-description)
- [Flattened File Object](#flattened-file-object)
- [Transaction Fields](#transaction-fields)
- [Access Privileges](#access-privileges)
- [Download Folder Actions](#download-folder-actions)
- [Transaction Sequences](#transaction-sequences)
- [Tracker Interface](#tracker-interface)
- [HTTP Tunneling](#http-tunneling)
- [Global Server](#global-server)

---

## Licensing

The Hotline Protocol is the property of Hotsprings Inc. It is licensed to you under the GPL, or a commercial license negotiated with Hotsprings Inc. If you do not have a commercial license, then this protocol is automatically GPL.

For most developers, the GPL is the best option. Contrary to conventional wisdom, there is no prohibition in the GPL to charging money for a GPL'd application. The GPL is about free as in speech, not free as in beer.

If you want to use the protocol to develop a closed source application, you can do so by contacting Hotsprings for a commercial license. Possession of a commercial license allows for conventional commercial development.

---

## Protocol Overview

Hotline client is an application executing on the user's computer, and providing user interface for end-user services (chat, messaging, file services and other). Hotline server provides services and facilitates communication between all clients that are currently connected to it. Tracker application stores the list of servers that register with it, and provides that list to clients that request it. All these applications use TCP/IP for communication.

To be able to connect to the specific server, IP address and port number must be provided to the client application. If client receives server's address from a tracker, the tracker will provide the client with complete address. Otherwise, the user of Hotline client software must manually set this address. IP port number, set in the Hotline client for a specific server, is called **base port number**. Additional port numbers utilized by the network protocol are determined by using this base port number:

| Port          | Usage                                   |
|---------------|-----------------------------------------|
| Base port     | Regular transactions                    |
| Base port + 1 | Upload/download                         |
| Base port + 2 | HTTP tunneling for regular transactions |
| Base port + 3 | HTTP tunneling for uploads/downloads    |

**Note:** Numeric data transmitted over the wire is always in network byte order (big-endian).

---

## Session Initialization

After establishing TCP connection, both client and server start the handshake process in order to confirm that each of them comply with requirements of the other. The information provided in this initial data exchange identifies protocols, and their versions, used in the communication. In the case where, after inspection, the capabilities of one of the subjects do not comply with the requirements of the other, the connection is dropped.

### Client Request

| Description     | Size | Data   | Note         |
|-----------------|------|--------|--------------|
| Protocol ID     | 4    | 'TRTP' | 0x54525450   |
| Sub-protocol ID | 4    |        | User defined |
| Version         | 2    | 1      | Currently 1  |
| Sub-version     | 2    |        | User defined |

### Server Reply

| Description | Size | Data   | Note                                             |
|-------------|------|--------|--------------------------------------------------|
| Protocol ID | 4    | 'TRTP' |                                                  |
| Error code  | 4    |        | Error code returned by the server (0 = no error) |

In the case of an error, client and server close the connection.

---

## Transactions

After the initial handshake, client and server communicate over the connection by sending and receiving transactions. Every transaction contains description (request) and/or status (reply) of the operation that is performed, and parameters used for that specific operation.

### Transaction Header

| Description | Size | Data   | Note                                                                        |
|-------------|------|--------|-----------------------------------------------------------------------------|
| Flags       | 1    | 0      | Reserved (should be 0)                                                      |
| Is reply    | 1    | 0 or 1 | Request (0) or reply (1)                                                    |
| Type        | 2    |        | Requested operation (user defined)                                          |
| ID          | 4    | Not 0  | Unique transaction ID (must be != 0)                                        |
| Error code  | 4    |        | Used in the reply (user defined, 0 = no error)                              |
| Total size  | 4    |        | Total data size for the transaction (all parts)                             |
| Data size   | 4    |        | Size of data in this transaction part (allows splitting large transactions) |

### Parameter List Header

| Description          | Size | Data | Note                                          |
|----------------------|------|------|-----------------------------------------------|
| Number of parameters | 2    |      | Number of the parameters for this transaction |
| Parameter list…      |      |      |                                               |

### Parameter Structure

| Description  | Size | Data | Note                  |
|--------------|------|------|-----------------------|
| Field ID     | 2    |      |                       |
| Field size   | 2    |      | Size of the data part |
| Field data…  | size |      | Actual field content  |

Every field data format is based on the field type. Currently, there are only 3 predefined field data types: **integer**, **string** and **binary**.

---

## Transaction Types (with Type ID)

This is the list of all transactions in the current version of Hotline software:

| ID  | Type                         | Initiator     | Constant                    |
|-----|------------------------------|---------------|-----------------------------|
| 100 | Error                        | ?             | myTran_Error                |
| 101 | Get messages                 | Client        | myTran_GetMsgs              |
| 102 | New message                  | Server        | myTran_NewMsg               |
| 103 | Old post news                | Client        | myTran_OldPostNews          |
| 104 | Server message               | Server        | myTran_ServerMsg            |
| 105 | Send chat                    | Client        | myTran_ChatSend             |
| 106 | Chat message                 | Server        | myTran_ChatMsg              |
| 107 | Login                        | Client        | myTran_Login                |
| 108 | Send instant message         | Client        | myTran_SendInstantMsg       |
| 109 | Show agreement               | Server        | myTran_ShowAgreement        |
| 110 | Disconnect user              | Client        | myTran_DisconnectUser       |
| 111 | Disconnect message           | Server        | myTran_DisconnectMsg        |
| 112 | Invite to a new chat         | Client        | myTran_InviteNewChat        |
| 113 | Invite to chat               | Client/Server | myTran_InviteToChat         |
| 114 | Reject chat invite           | Client        | myTran_RejectChatInvite     |
| 115 | Join chat                    | Client        | myTran_JoinChat             |
| 116 | Leave chat                   | Client        | myTran_LeaveChat            |
| 117 | Notify chat of a user change | Server        | myTran_NotifyChatChangeUser |
| 118 | Notify chat of a delete user | Server        | myTran_NotifyChatDeleteUser |
| 119 | Notify of a chat subject     | Server        | myTran_NotifyChatSubject    |
| 120 | Set chat subject             | Client        | myTran_SetChatSubject       |
| 121 | Agreed                       | Client        | myTran_Agreed               |
| 122 | Server banner                | Server        | myTran_ServerBanner         |
| 200 | Get file name list           | Client        | myTran_GetFileNameList      |
| 202 | Download file                | Client        | myTran_DownloadFile         |
| 203 | Upload file                  | Client        | myTran_UploadFile           |
| 204 | Delete file                  | Client        | myTran_DeleteFile           |
| 205 | New folder                   | Client        | myTran_NewFolder            |
| 206 | Get file info                | Client        | myTran_GetFileInfo          |
| 207 | Set file info                | Client        | myTran_SetFileInfo          |
| 208 | Move file                    | Client        | myTran_MoveFile             |
| 209 | Make file alias              | Client        | myTran_MakeFileAlias        |
| 210 | Download folder              | Client        | myTran_DownloadFldr         |
| 211 | Download info                | Server        | myTran_DownloadInfo         |
| 212 | Download banner              | Client        | myTran_DownloadBanner       |
| 213 | Upload folder                | Client        | myTran_UploadFldr           |
| 300 | Get user name list           | Client        | myTran_GetUserNameList      |
| 301 | Notify of a user change      | Server        | myTran_NotifyChangeUser     |
| 302 | Notify of a delete user      | Server        | myTran_NotifyDeleteUser     |
| 303 | Get client info text         | Client        | myTran_GetClientInfoText    |
| 304 | Set client user info         | Client        | myTran_SetClientUserInfo    |
| 350 | New user                     | Client        | myTran_NewUser              |
| 351 | Delete user                  | Client        | myTran_DeleteUser           |
| 352 | Get user                     | Client        | myTran_GetUser              |
| 353 | Set user                     | Client        | myTran_SetUser              |
| 354 | User access                  | Server        | myTran_UserAccess           |
| 355 | User broadcast               | Client/Server | myTran_UserBroadcast        |
| 370 | Get news category name list  | Client        | myTran_GetNewsCatNameList   |
| 371 | Get news article name list   | Client        | myTran_GetNewsArtNameList   |
| 380 | Delete news item             | Client        | myTran_DelNewsItem          |
| 381 | New news folder              | Client        | myTran_NewNewsFldr          |
| 382 | New news category            | Client        | myTran_NewNewsCat           |
| 400 | Get news article data        | Client        | myTran_GetNewsArtData       |
| 410 | Post news article            | Client        | myTran_PostNewsArt          |
| 411 | Delete news article          | Client        | myTran_DelNewsArt           |

### Related Transaction Groups

#### User Login and Management

| ID  | Type                    | Initiator |
|-----|-------------------------|-----------|
| 107 | Login                   | Client    |
| 109 | Show agreement          | Server    |
| 121 | Agreed                  | Client    |
| 304 | Set client user info    | Client    |
| 301 | Notify of a user change | Server    |
| 300 | Get user name list      | Client    |
| 302 | Notify of a delete user | Server    |

#### Chat Transactions

| ID  | Type                         | Initiator     |
|-----|------------------------------|---------------|
| 115 | Join chat                    | Client        |
| 112 | Invite to a new chat         | Client        |
| 113 | Invite to chat               | Client/Server |
| 114 | Reject chat invite           | Client        |
| 117 | Notify chat of a user change | Server        |
| 116 | Leave chat                   | Client        |
| 118 | Notify chat of a delete user | Server        |
| 120 | Set chat subject             | Client        |
| 119 | Notify of a chat subject     | Server        |
| 105 | Send chat                    | Client        |
| 106 | Chat message                 | Server        |

#### Messaging Transactions

| ID  | Type                 | Initiator |
|-----|----------------------|-----------|
| 104 | Server message       | Server    |
| 108 | Send instant message | Client    |

---

## Transaction Description

Transaction types are described using the following format:

- **Constant:** Constant identifier used in the old version of the application
- **Access:** Specifies access privilege required to perform the transaction
- **Initiator:** Specifies transaction initiator (client or server)
- **Fields used in the request:** List of fields sent by the transaction initiator
- **Fields used in the reply:** List of fields sent back to the transaction initiator
- **Reply is not sent:** Receiver of transaction is not sending reply
- **Reply is not expected:** Sender of transaction is not expecting reply

---

### Error (100)

- **Constant:** myTran_Error
- **Initiator:** None (?)

---

### Get Messages (101)

- **Constant:** myTran_GetMsgs
- **Initiator:** Client

**Fields used in the request:** None

**Fields used in the reply:**

| ID  | Field Name | Note         |
|-----|------------|--------------|
| 101 | Data       | Message text |

---

### New Message (102)

- **Constant:** myTran_NewMsg
- **Initiator:** Server

**Fields used in the request:**

| ID  | Field Name | Note      |
|-----|------------|-----------|
| 101 | Data       | News text |

**Reply is not sent.**

---

### Old Post News (103)

- **Constant:** myTran_OldPostNews
- **Access:** News Post Article (21)
- **Initiator:** Client

**Fields used in the request:**

| ID  | Field Name | Note |
|-----|------------|------|
| 101 | Data       |      |

**Fields used in the reply:** None

---

### Server Message (104)

- **Constant:** myTran_ServerMsg
- **Initiator:** Server

Receive a message from the user on the current server, server's administrator, or server software itself.

**Fields used in the request:**

| ID  | Field Name      | Note                                                                              |
|-----|-----------------|-----------------------------------------------------------------------------------|
| 103 | User ID         |                                                                                   |
| 102 | User name       |                                                                                   |
| 113 | Options         | Bitmap: Automatic response (4), Refuse private chat (2), Refuse private message (1) |
| 101 | Data            | Message to display                                                                |
| 214 | Quoting message | Message to quote                                                                  |

If User ID (103) field is not sent, receiver assumes that sender uses the following fields:

| ID  | Field Name   | Note                                                  |
|-----|--------------|-------------------------------------------------------|
| 101 | Data         |                                                       |
| 109 | Chat options | Server message (1) or admin message (any other value) |

**Reply is not sent.**

---

### Send Chat (105)

- **Constant:** myTran_ChatSend
- **Access:** Send Chat (10)
- **Initiator:** Client

Send a chat message to the chat.

**Fields used in the request:**

| ID  | Field Name   | Note                                                |
|-----|--------------|-----------------------------------------------------|
| 109 | Chat options | Optional - Normal (0) or alternate (1) chat message |
| 114 | Chat ID      | Optional                                            |
| 101 | Data         | Chat message string                                 |

**Reply is not expected.**

---

### Chat Message (106)

- **Constant:** myTran_ChatMsg
- **Initiator:** Server

Receive a chat message from the chat.

**Fields used in the request:**

| ID  | Field Name | Note      |
|-----|------------|-----------|
| 114 | Chat ID    |           |
| 101 | Data       | Chat text |

If Chat ID is not available, the Data field contains:

| ID  | Field Name | Note                 |
|-----|------------|----------------------|
| 101 | Data       | Special chat message |

**Reply is not sent.**

---

### Login (107)

- **Constant:** myTran_Login
- **Initiator:** Client

Start login sequence with the server (see Transaction Sequences).

**Fields used in the request:**

| ID  | Field Name    | Note          |
|-----|---------------|---------------|
| 105 | User login    |               |
| 106 | User password |               |
| 160 | Version       | Currently 151 |

**Fields used in the reply:**

| ID  | Field Name | Note |
|-----|------------|------|
| 160 | Version    |      |

If Version is >= 151, additional fields are included:

| ID  | Field Name  | Note                                        |
|-----|-------------|---------------------------------------------|
| 161 | Banner ID   | Used for making HTTP request to get banner  |
| 162 | Server name | Server name string                          |

If server version is < 151, client sends Set Client User Info (304) transaction with only User Name (102) and User Icon ID (104) fields used, and does not expect a reply. It does not expect agreement to be received (109). Subsequently, it sends Get User Name List (300) request, followed by Get File Name List (200) or Get News Category Name List (370), depending on user preferences. After that, a banner is requested from HTTP server.

---

### Send Instant Message (108)

- **Constant:** myTran_SendInstantMsg
- **Initiator:** Client

Send instant message to the user on the current server.

**Fields used in the request:**

| ID  | Field Name      | Note                                                                                              |
|-----|-----------------|---------------------------------------------------------------------------------------------------|
| 103 | User ID         |                                                                                                   |
| 113 | Options         | myOpt_UserMessage (1), myOpt_RefuseMessage (2), myOpt_RefuseChat (3), myOpt_AutomaticResponse (4) |
| 101 | Data            | Optional                                                                                          |
| 214 | Quoting message | Optional                                                                                          |

**Fields used in the reply:** None

---

### Show Agreement (109)

- **Constant:** myTran_ShowAgreement
- **Initiator:** Server

Receive agreement that will be presented to the user of the client application. This transaction is part of the login sequence.

**Fields used in the request:**

| ID  | Field Name          | Note                                      |
|-----|---------------------|-------------------------------------------|
| 101 | Data                | Agreement string                          |
| 154 | No server agreement | Optional - No agreement available (1)     |
| 152 | Server banner type  |                                           |
| 153 | Server banner URL   | Optional - If banner type is URL (1)      |
| 151 |                     | Optional - If banner type is not URL (1)  |

**Reply is not sent.**

---

### Disconnect User (110)

- **Constant:** myTran_DisconnectUser
- **Access:** Disconnect User (22)
- **Initiator:** Client

Disconnect user from the current server.

**Fields used in the request:**

| ID  | Field Name | Note                   |
|-----|------------|------------------------|
| 103 | User ID    |                        |
| 113 | Options    | Optional - Ban options |
| 101 | Data       | Optional - Name?       |

**Fields used in the reply:** None

---

### Disconnect Message (111)

- **Constant:** myTran_DisconnectMsg
- **Initiator:** Server

Receive disconnect message from the server. Upon receiving this transaction, client should close the connection with server.

**Fields used in the request:**

| ID  | Field Name | Note                                         |
|-----|------------|----------------------------------------------|
| 101 | Data       | Message to display on disconnect (mandatory) |

**Reply is not sent.**

---

### Invite New Chat (112)

- **Constant:** myTran_InviteNewChat
- **Initiator:** Client

Invite users to the new chat.

**Fields used in the request:**

| ID   | Field Name | Note                      |
|------|------------|---------------------------|
| 103  | User ID    | Optional                  |
| 103… | User ID…   | Optional - More user IDs… |

**Fields used in the reply:**

| ID  | Field Name   | Note |
|-----|--------------|------|
| 103 | User ID      |      |
| 104 | User icon ID |      |
| 112 | User flags   |      |
| 102 | User name    |      |
| 114 | Chat ID      |      |

---

### Invite To Chat (113)

- **Constant:** myTran_InviteToChat
- **Initiator:** Client

Invite user to the existing chat.

**Fields used in the request:**

| ID  | Field Name | Note           |
|-----|------------|----------------|
| 103 | User ID    | User to invite |
| 114 | Chat ID    |                |

**Reply is not expected.**

The server can also be an initiator of this transaction.

**Initiator:** Server

**Fields used in the request:**

| ID  | Field Name | Note           |
|-----|------------|----------------|
| 114 | Chat ID    |                |
| 103 | User ID    | User to invite |
| 102 | User name  |                |

**Reply is not sent.**

When client receives this message from the server with version < 151, and client has automatic response or reject chat flag set, Reject Chat Invite (114) transaction is sent back to the server.

---

### Reject Chat Invite (114)

- **Constant:** myTran_RejectChatInvite
- **Initiator:** Client

Reject invitation to join the chat.

**Fields used in the request:**

| ID  | Field Name | Note |
|-----|------------|------|
| 114 | Chat ID    |      |

**Reply is not expected.**

---

### Join Chat (115)

- **Constant:** myTran_JoinChat
- **Initiator:** Client

Join the chat.

**Fields used in the request:**

| ID  | Field Name | Note |
|-----|------------|------|
| 114 | Chat ID    |      |

**Fields used in the reply:**

| ID   | Field Name           | Note                                  |
|------|----------------------|---------------------------------------|
| 115  | Chat subject         |                                       |
| 300  | User name with info  | Optional                              |
| 300… | User name with info… | Optional - More user names with info  |

---

### Leave Chat (116)

- **Constant:** myTran_LeaveChat
- **Initiator:** Client

Leave the chat.

**Fields used in the request:**

| ID  | Field Name | Note |
|-----|------------|------|
| 114 | Chat ID    |      |

**Reply is not expected.**

---

### Notify Chat Change User (117)

- **Constant:** myTran_NotifyChatChangeUser
- **Initiator:** Server

Notify the user of the chat that the information for some another user changed, or that a new user just joined the chat. This information should be added to (user joined the chat), or updated (user changed its info) in the chat user list.

**Fields used in the request:**

| ID  | Field Name   | Note |
|-----|--------------|------|
| 114 | Chat ID      |      |
| 103 | User ID      |      |
| 104 | User icon ID |      |
| 112 | User flags   |      |
| 102 | User name    |      |

**Reply is not sent.**

In the Hotline implementation v1.8x, this transaction is in fact used only when the user joins the chat. The user information update done by Notify Change User (301) transaction is also applied to any chat rooms on the clients receiving the update.

---

### Notify Chat Delete User (118)

- **Constant:** myTran_NotifyChatDeleteUser
- **Initiator:** Server

Notify the user of the chat that a user left that chat. The client should update the chat user list.

**Fields used in the request:**

| ID  | Field Name | Note |
|-----|------------|------|
| 114 | Chat ID    |      |
| 103 | User ID    |      |

**Reply is not sent.**

---

### Notify Chat Subject (119)

- **Constant:** myTran_NotifyChatSubject
- **Initiator:** Server

Notify the user of the chat of the chat subject.

**Fields used in the request:**

| ID  | Field Name   | Note                |
|-----|--------------|---------------------|
| 114 | Chat ID      |                     |
| 115 | Chat subject | Chat subject string |

**Reply is not sent.**

---

### Set Chat Subject (120)

- **Constant:** myTran_SetChatSubject
- **Initiator:** Client

Set chat subject for the chat.

**Fields used in the request:**

| ID  | Field Name   | Note                |
|-----|--------------|---------------------|
| 114 | Chat ID      |                     |
| 115 | Chat subject | Chat subject string |

**Reply is not expected.**

---

### Agreed (121)

- **Constant:** myTran_Agreed
- **Initiator:** Client

Notify the server that the user accepted the server agreement.

**Fields used in the request:**

| ID  | Field Name         | Note                                                                                        |
|-----|--------------------|---------------------------------------------------------------------------------------------|
| 102 | User name          |                                                                                             |
| 104 | User icon ID       |                                                                                             |
| 113 | Options            | Bitmap: Automatic response (4), Refuse private chat (2), Refuse private message (1)        |
| 215 | Automatic response | Optional - Automatic response string used only if the options field indicates this feature  |

**Fields used in the reply:** None

After receiving server's acknowledgement, the client sends Get User Name List (300) request, followed by Get File Name List (200) or Get News Category Name List (370), depending on user preferences.

---

### Server Banner (122)

- **Constant:** myTran_ServerBanner
- **Initiator:** Server

Notify the client that a new banner should be displayed.

**Fields used in the request:**

| ID  | Field Name         | Note                     |
|-----|--------------------|--------------------------|
| 152 | Server banner type | Uses only literal values |
| 153 | Server banner URL  | Optional                 |

**Reply is not sent.**

If banner type is URL, it is requested from that URL. Otherwise, the banner is requested from the server by Download Banner (212) request.

This transaction uses only literal value constants in the banner type field (e.g., 'URL ', 'JPEG' or other).

---

### Get File Name List (200)

- **Constant:** myTran_GetFileNameList
- **Initiator:** Client

Get the list of file names from the specified folder.

**Fields used in the request:**

| ID  | Field Name | Note                                             |
|-----|------------|--------------------------------------------------|
| 202 | File path  | Optional - If not specified, root folder assumed |

**Fields used in the reply:**

| ID   | Field Name           | Note                                 |
|------|----------------------|--------------------------------------|
| 200  | File name with info  | Optional                             |
| 200… | File name with info… | Optional - More file names with info |

---

### Download File (202)

- **Constant:** myTran_DownloadFile
- **Access:** Download File (2)
- **Initiator:** Client

Download the file from the specified path on the server.

**Fields used in the request:**

| ID  | Field Name            | Note                                                                              |
|-----|-----------------------|-----------------------------------------------------------------------------------|
| 201 | File name             |                                                                                   |
| 202 | File path             |                                                                                   |
| 203 | File resume data      | Optional                                                                          |
| 204 | File transfer options | Optional - Currently set to 2, used only for TEXT, JPEG, GIFF, BMP or PICT files  |

**Fields used in the reply:**

| ID  | Field Name       | Note                          |
|-----|------------------|-------------------------------|
| 108 | Transfer size    | Size of data to be downloaded |
| 207 | File size        |                               |
| 107 | Reference number | Used later for transfer       |
| 116 | Waiting count    |                               |

After receiving reply from the server, the client opens TCP (or HTTP) connection to base port + 1 (HTTP uses base port + 3). On successful establishment, client sends the following record using the new connection:

| Description      | Size | Data   | Note                                          |
|------------------|------|--------|-----------------------------------------------|
| Protocol         | 4    | 'HTXF' | 0x48545846                                    |
| Reference number | 4    |        | Use reference number received from the server |
| Data size        | 4    | 0      |                                               |
| RSVD             | 4    | 0      | ?                                             |

After this, server sends the flattened file object (see Flattened File Object) using this new TCP connection.

---

### Upload File (203)

- **Constant:** myTran_UploadFile
- **Access:** Upload File (1)
- **Initiator:** Client

Upload a file to the specified path on the server.

**Fields used in the request:**

| ID  | Field Name            | Note                                                           |
|-----|-----------------------|----------------------------------------------------------------|
| 201 | File name             |                                                                |
| 202 | File path             |                                                                |
| 204 | File transfer options | Optional - Used only to resume download, currently has value 2 |
| 108 | File transfer size    | Optional - Used if download is not resumed                     |

**Fields used in the reply:**

| ID  | Field Name       | Note                                    |
|-----|------------------|-----------------------------------------|
| 203 | File resume data | Optional - Used only to resume download |
| 107 | Reference number |                                         |

After receiving reply from the server, the client opens TCP (or HTTP) connection to base port + 1 (HTTP uses base port + 3). On successful establishment, client sends the following record using the new connection:

| Description      | Size | Data   | Note                                          |
|------------------|------|--------|-----------------------------------------------|
| Protocol         | 4    | 'HTXF' | 0x48545846                                    |
| Reference number | 4    |        | Use reference number received from the server |
| Data size        | 4    |        | File size                                     |
| RSVD             | 4    | 0      | ?                                             |

After this, client sends the flattened file object (see Flattened File Object) using this new TCP connection.

---

### Delete File (204)

- **Constant:** myTran_DeleteFile
- **Access:** Delete File (0) or Delete Folder (6)
- **Initiator:** Client

Delete the specific file from the server.

**Fields used in the request:**

| ID  | Field Name | Note |
|-----|------------|------|
| 201 | File name  |      |
| 202 | File path  |      |

**Fields used in the reply:** None

---

### New Folder (205)

- **Constant:** myTran_NewFolder
- **Access:** Create Folder (5)
- **Initiator:** Client

Create a new folder on the server.

**Fields used in the request:**

| ID  | Field Name | Note |
|-----|------------|------|
| 201 | File name  |      |
| 202 | File path  |      |

**Fields used in the reply:** None

---

### Get File Info (206)

- **Constant:** myTran_GetFileInfo
- **Initiator:** Client

Request file information from the server.

**Fields used in the request:**

| ID  | Field Name | Note     |
|-----|------------|----------|
| 201 | File name  |          |
| 202 | File path  | Optional |

**Fields used in the reply:**

| ID  | Field Name          | Note           |
|-----|---------------------|----------------|
| 201 | File name           |                |
| 205 | File type string    |                |
| 206 | File creator string |                |
| 210 | File comment        | Comment string |
| 213 | File type           |                |
| 208 | File create date    |                |
| 209 | File modify date    |                |
| 207 | File size           |                |

---

### Set File Info (207)

- **Constant:** myTran_SetFileInfo
- **Access:** Set File Comment (28) or Set Folder Comment (29)
- **Initiator:** Client

Set information for the specified file on the server.

**Fields used in the request:**

| ID  | Field Name    | Note     |
|-----|---------------|----------|
| 201 | File name     |          |
| 202 | File path     | Optional |
| 211 | File new name | Optional |
| 210 | File comment  | Optional |

**Fields used in the reply:** None

---

### Move File (208)

- **Constant:** myTran_MoveFile
- **Initiator:** Client

Move the file from one folder to another on the same server.

**Fields used in the request:**

| ID  | Field Name    | Note |
|-----|---------------|------|
| 201 | File name     |      |
| 202 | File path     |      |
| 212 | File new path |      |

**Fields used in the reply:** None

---

### Make File Alias (209)

- **Constant:** myTran_MakeFileAlias
- **Access:** Make Alias (31)
- **Initiator:** Client

Make the file alias using the specified path.

**Fields used in the request:**

| ID  | Field Name    | Note             |
|-----|---------------|------------------|
| 201 | File name     |                  |
| 202 | File path     |                  |
| 212 | File new path | Destination path |

**Fields used in the reply:** None

---

### Download Folder (210)

- **Constant:** myTran_DownloadFldr
- **Access:** Download File (2)
- **Initiator:** Client

Download all files from the specified folder and its subfolders on the server.

**Fields used in the request:**

| ID  | Field Name | Note |
|-----|------------|------|
| 201 | File name  |      |
| 202 | File path  |      |

**Fields used in the reply:**

| ID  | Field Name        | Note                          |
|-----|-------------------|-------------------------------|
| 220 | Folder item count |                               |
| 107 | Reference number  | Used later for transfer       |
| 108 | Transfer size     | Size of data to be downloaded |
| 116 | Waiting count     |                               |

After receiving reply from the server, the client opens TCP (or HTTP) connection to base port + 1 (HTTP uses base port + 3). On successful establishment, client sends the following record using the new connection:

| Description            | Size | Data   | Note                                          |
|------------------------|------|--------|-----------------------------------------------|
| Protocol               | 4    | 'HTXF' | 0x48545846                                    |
| Reference number       | 4    |        | Use reference number received from the server |
| Data size              | 4    | 0      |                                               |
| Type                   | 2    | 1      |                                               |
| RSVD                   | 2    | 0      | ?                                             |
| Download folder action | 2    | 3      | Next file action (3)                          |

For every item in the folder, server replies with:

| Description | Size | Data | Note |
|-------------|------|------|------|
| Header size | 2    |      |      |
| Header data | size |      |      |

Header data contains:

| Description | Size | Data | Note |
|-------------|------|------|------|
| Type        | 2    |      | ?    |
| File path   | rest |      |      |

After receiving this header, client can reply in 3 ways:

**(1) If type is an odd number (unknown type?), or file download for the current file is completed:**

| Description            | Size | Data | Note                 |
|------------------------|------|------|----------------------|
| Download folder action | 2    | 3    | Next file action (3) |

This notifies the server to send next item header.

**(2) If download of a file is to be resumed:**

| Description            | Size | Data | Note                        |
|------------------------|------|------|-----------------------------|
| Download folder action | 2    | 2    | Resume file transfer (2)    |
| Resume data size       | 2    |      |                             |
| File resume data       | size |      | See content for field (203) |

**(3) Otherwise, file download is requested by:**

| Description            | Size | Data | Note                                      |
|------------------------|------|------|-------------------------------------------|
| Download folder action | 2    | 1    | Send file action (1) starts file download |

When download is requested (case 2 or 3), server replies with:

| Description    | Size | Data | Note                        |
|----------------|------|------|-----------------------------|
| File size      | 4    |      |                             |
| File content…  | size |      | Actual flattened file object |

After every file download, client could request next file:

| Description            | Size | Data | Note                 |
|------------------------|------|------|----------------------|
| Download folder action | 2    | 3    | Next file action (3) |

---

### Download Info (211)

- **Constant:** myTran_DownloadInfo
- **Initiator:** Server

Notify the client that all download slots on the server are full.

**Fields used in the request:**

| ID  | Field Name       | Note                           |
|-----|------------------|--------------------------------|
| 107 | Reference number | Download reference number      |
| 116 | Waiting count    | Position in the server's queue |

**Reply is not sent.**

---

### Download Banner (212)

- **Constant:** myTran_DownloadBanner
- **Initiator:** Client

Request a new banner from the server.

**Fields used in the request:** None

**Fields used in the reply:**

| ID  | Field Name       | Note                          |
|-----|------------------|-------------------------------|
| 107 | Reference number | Used later for transfer       |
| 108 | Transfer size    | Size of data to be downloaded |

After receiving reply from the server, the client opens TCP (or HTTP) connection to base port + 1 (HTTP uses base port + 3). On successful establishment, client sends the following record using the new connection:

| Description      | Size | Data   | Note                                          |
|------------------|------|--------|-----------------------------------------------|
| Protocol         | 4    | 'HTXF' | 0x48545846                                    |
| Reference number | 4    |        | Use reference number received from the server |
| Data size        | 4    | 0      |                                               |
| Type             | 2    | 2      |                                               |
| RSVD             | 2    | 0      | ?                                             |

After this, server sends the file content using this new TCP connection.

---

### Upload Folder (213)

- **Constant:** myTran_UploadFldr
- **Access:** Upload File (1)
- **Initiator:** Client

Upload all files from the local folder and its subfolders, to the specified path on the server.

**Fields used in the request:**

| ID  | Field Name            | Note                                  |
|-----|-----------------------|---------------------------------------|
| 201 | File name             |                                       |
| 202 | File path             |                                       |
| 108 | Transfer size         | Total size of all items in the folder |
| 220 | Folder item count     |                                       |
| 204 | File transfer options | Optional - Currently set to 1         |

**Fields used in the reply:**

| ID  | Field Name       | Note                    |
|-----|------------------|-------------------------|
| 107 | Reference number | Used later for transfer |

After receiving reply from the server, the client opens TCP (or HTTP) connection to base port + 1 (HTTP uses base port + 3). On successful establishment, client sends the following record using the new connection:

| Description      | Size | Data   | Note                                          |
|------------------|------|--------|-----------------------------------------------|
| Protocol         | 4    | 'HTXF' | 0x48545846                                    |
| Reference number | 4    |        | Use reference number received from the server |
| Data size        | 4    | 0      |                                               |
| Type             | 2    | 1      |                                               |
| RSVD             | 2    | 0      | ?                                             |

Server can reply with:

| Description            | Size | Data | Note                 |
|------------------------|------|------|----------------------|
| Download folder action | 2    | 3    | Next file action (3) |

After which client sends:

| Description     | Size | Data   | Note                                                          |
|-----------------|------|--------|---------------------------------------------------------------|
| Data size       | 2    |        | Size of this structure (not including data size element itself) |
| Is folder       | 2    | 0 or 1 | Is the following file path a folder                           |
| Path item count | 2    |        | Number of items in the path                                   |
| File name path… |      |        |                                                               |

File name path contains:

| Description      | Size | Data | Note        |
|------------------|------|------|-------------|
|                  | 2    | 0    | Currently 0 |
| Name size        | 1    |      |             |
| File/folder name | size |      |             |

After every file, server can send one of 3 requests:

**(1) Request next file:**

| Description            | Size | Data | Note                 |
|------------------------|------|------|----------------------|
| Download folder action | 2    | 3    | Next file action (3) |

**(2) Resume a file download procedure:**

| Description            | Size | Data | Note                        |
|------------------------|------|------|-----------------------------|
| Download folder action | 2    | 2    | Resume file transfer (2)    |
| Resume data size       | 2    |      |                             |
| File resume data       | size |      | See content for field (203) |

**(3) Request a file download:**

| Description            | Size | Data | Note                                      |
|------------------------|------|------|-------------------------------------------|
| Download folder action | 2    | 1    | Send file action (1) starts file download |

Client replies to download requests with:

| Description | Size | Data | Note              |
|-------------|------|------|-------------------|
| File size   | 4    |      | Current file size |

After this client sends the flattened file object (see Flattened File Object).

---

### Get User Name List (300)

- **Constant:** myTran_GetUserNameList
- **Initiator:** Client

Request the list of all users connected to the current server.

**Fields used in the request:** None

**Fields used in the reply:**

| ID   | Field Name           | Note                                 |
|------|----------------------|--------------------------------------|
| 300  | User name with info  | Optional                             |
| 300… | User name with info… | Optional - More user names with info |

---

### Notify Change User (301)

- **Constant:** myTran_NotifyChangeUser
- **Initiator:** Server

Notify the user that the information for some another user changed, or that a new user just connected to the server. This information is to be added to (user joined), or updated (user changed its info) in the existing user list.

**Fields used in the request:**

| ID  | Field Name   | Note |
|-----|--------------|------|
| 103 | User ID      |      |
| 104 | User icon ID |      |
| 112 | User flags   |      |
| 102 | User name    |      |

**Reply is not sent.**

In the Hotline implementation v1.8x, this transaction is also applied to any chat rooms on the clients receiving the update.

---

### Notify Delete User (302)

- **Constant:** myTran_NotifyDeleteUser
- **Initiator:** Server

Notify the user that some another user disconnected from the server. The client should update the existing user list.

**Fields used in the request:**

| ID  | Field Name | Note |
|-----|------------|------|
| 103 | User ID    |      |

**Reply is not sent.**

---

### Get Client Info Text (303)

- **Constant:** myTran_GetClientInfoText
- **Access:** Get Client Info (24)
- **Initiator:** Client

Request user information for the specific user.

**Fields used in the request:**

| ID  | Field Name | Note |
|-----|------------|------|
| 103 | User ID    |      |

**Fields used in the reply:**

| ID  | Field Name | Note                  |
|-----|------------|-----------------------|
| 102 | User name  |                       |
| 101 | Data       | User info text string |

---

### Set Client User Info (304)

- **Constant:** myTran_SetClientUserInfo
- **Initiator:** Client

Set user preferences on the server.

**Fields used in the request:**

| ID  | Field Name         | Note                                                                                        |
|-----|--------------------|---------------------------------------------------------------------------------------------|
| 102 | User name          |                                                                                             |
| 104 | User icon ID       |                                                                                             |
| 113 | Options            | Bitmap: Automatic response (4), Refuse private chat (2), Refuse private message (1)        |
| 215 | Automatic response | Optional - Automatic response string used only if the options field indicates this feature  |

**Reply is not expected.**

---

### New User (350)

- **Constant:** myTran_NewUser
- **Initiator:** Client

Add a new user to the server's list of allowed users.

**Fields used in the request:**

| ID  | Field Name    | Note                                                  |
|-----|---------------|-------------------------------------------------------|
| 105 | User login    |                                                       |
| 106 | User password |                                                       |
| 102 | User name     |                                                       |
| 110 | User access   | User access privileges bitmap (see Access Privileges) |

**Fields used in the reply:** None

---

### Delete User (351)

- **Constant:** myTran_DeleteUser
- **Initiator:** Client

Delete the specific user from the server's list of allowed users.

**Fields used in the request:**

| ID  | Field Name | Note |
|-----|------------|------|
| 105 | User login |      |

**Fields used in the reply:** None

---

### Get User (352)

- **Constant:** myTran_GetUser
- **Initiator:** Client

Request the information for the specific user from the server's list of allowed users.

**Fields used in the request:**

| ID  | Field Name | Note |
|-----|------------|------|
| 105 | User login |      |

**Fields used in the reply:**

| ID  | Field Name    | Note                                                              |
|-----|---------------|-------------------------------------------------------------------|
| 102 | User name     |                                                                   |
| 105 | User login    | Every character in this string is negated (login[i] = ~login[i])  |
| 106 | User password |                                                                   |
| 110 | User access   | User access privileges bitmap (see Access Privileges)             |

---

### Set User (353)

- **Constant:** myTran_SetUser
- **Initiator:** Client

Set the information for the specific user in the server's list of allowed users.

**Fields used in the request:**

| ID  | Field Name    | Note                                                  |
|-----|---------------|-------------------------------------------------------|
| 105 | User login    |                                                       |
| 106 | User password |                                                       |
| 102 | User name     |                                                       |
| 110 | User access   | User access privileges bitmap (see Access Privileges) |

**Fields used in the reply:** None

---

### User Access (354)

- **Constant:** myTran_UserAccess
- **Initiator:** Server

Set access privileges for the current user.

**Fields used in the request:**

| ID  | Field Name  | Note                                                  |
|-----|-------------|-------------------------------------------------------|
| 110 | User access | User access privileges bitmap (see Access Privileges) |

**Reply is not sent.**

---

### User Broadcast (355)

- **Constant:** myTran_UserBroadcast
- **Access:** Broadcast (32)
- **Initiator:** Client

Broadcast the message to all users on the server.

**Fields used in the request:**

| ID  | Field Name | Note |
|-----|------------|------|
| 101 | Data       |      |

**Fields used in the reply:** None

The server can also be an initiator of this transaction.

**Initiator:** Server

**Fields used in the request:**

| ID  | Field Name | Note                  |
|-----|------------|-----------------------|
| 101 | Data       | Administrator message |

**Reply is not sent.**

---

### Get News Category Name List (370)

- **Constant:** myTran_GetNewsCatNameList
- **Initiator:** Client

Get the list of category names at the specified news path.

**Fields used in the request:**

| ID  | Field Name | Note     |
|-----|------------|----------|
| 325 | News path  | Optional |

**Fields used in the reply:**

| ID   | Field Name                | Note                             |
|------|---------------------------|----------------------------------|
| 323  | News category list data   | Optional                         |
| 323… | News category list data…  | Optional - More news categories  |

If version of client/server is 1.5 (prior to April 15, 1999?), instead of the previous reply, the following is sent:

| ID   | Field Name                | Note                             |
|------|---------------------------|----------------------------------|
| 320  | News category list data   | Optional                         |
| 320… | News category list data…  | Optional - More news categories  |

---

### Get News Article Name List (371)

- **Constant:** myTran_GetNewsArtNameList
- **Initiator:** Client

Get the list of article names at the specified news path.

**Fields used in the request:**

| ID  | Field Name | Note     |
|-----|------------|----------|
| 325 | News path  | Optional |

**Fields used in the reply:**

| ID  | Field Name             | Note     |
|-----|------------------------|----------|
| 321 | News article list data | Optional |

---

### Delete News Item (380)

- **Constant:** myTran_DelNewsItem
- **Access:** News Delete Folder (37) or News Delete Category (35)
- **Initiator:** Client

Delete an existing news item from the server.

**Fields used in the request:**

| ID  | Field Name | Note |
|-----|------------|------|
| 325 | News path  |      |

**Fields used in the reply:** None

---

### New News Folder (381)

- **Constant:** myTran_NewNewsFldr
- **Access:** News Create Folder (36)
- **Initiator:** Client

Create new news folder on the server.

**Fields used in the request:**

| ID  | Field Name | Note |
|-----|------------|------|
| 201 | File name  |      |
| 325 | News path  |      |

**Fields used in the reply:** None

---

### New News Category (382)

- **Constant:** myTran_NewNewsCat
- **Access:** News Create Category (34)
- **Initiator:** Client

Create new news category on the server.

**Fields used in the request:**

| ID  | Field Name         | Note |
|-----|--------------------| -----|
| 322 | News category name |      |
| 325 | News path          |      |

**Fields used in the reply:** None

---

### Get News Article Data (400)

- **Constant:** myTran_GetNewsArtData
- **Access:** News Read Article (20)
- **Initiator:** Client

Request information about the specific news article.

**Fields used in the request:**

| ID  | Field Name               | Note |
|-----|--------------------------|------|
| 325 | News path                |      |
| 326 | News article ID          |      |
| 327 | News article data flavor |      |

**Fields used in the reply:**

| ID  | Field Name               | Note                                                         |
|-----|--------------------------|--------------------------------------------------------------|
| 328 | News article title       |                                                              |
| 329 | News article poster      |                                                              |
| 330 | News article date        |                                                              |
| 331 | Previous article ID      |                                                              |
| 332 | Next article ID          |                                                              |
| 335 | Parent article ID        |                                                              |
| 336 | First child article ID   |                                                              |
| 327 | News article data flavor | Should be "text/plain" - Other values are currently ignored  |
| 333 | News article data        | Optional (if data flavor is "text/plain")                    |

---

### Post News Article (410)

- **Constant:** myTran_PostNewsArt
- **Access:** News Post Article (21)
- **Initiator:** Client

Post new news article on the server.

**Fields used in the request:**

| ID  | Field Name               | Note                      |
|-----|--------------------------|---------------------------|
| 325 | News path                |                           |
| 326 | News article ID          | ID of the parent article? |
| 328 | News article title       |                           |
| 334 | News article flags       |                           |
| 327 | News article data flavor | Currently "text/plain"    |
| 333 | News article data        |                           |

**Fields used in the reply:** None

---

### Delete News Article (411)

- **Constant:** myTran_DelNewsArt
- **Access:** News Delete Article (33)
- **Initiator:** Client

Delete the specific news article.

**Fields used in the request:**

| ID  | Field Name                       | Note                                 |
|-----|----------------------------------|--------------------------------------|
| 325 | News path                        |                                      |
| 326 | News article ID                  |                                      |
| 337 | News article – recursive delete  | Delete child articles (1) or not (0) |

**Fields used in the reply:** None

---

## Flattened File Object

Transactions 202 (Download File), 203 (Upload File), 210 (Download Folder) and 213 (Upload Folder) format the file object in the following way:

### Flat File Header

| Description | Size | Data   | Note       |
|-------------|------|--------|------------|
| Format      | 4    | 'FILP' | 0x46494C50 |
| Version     | 2    | 1      |            |
| RSVD        | 16   |        |            |
| Fork count  | 2    | 2      |            |

### Flat File Information Fork Header

| Description      | Size | Data   | Note                                   |
|------------------|------|--------|----------------------------------------|
| Fork type        | 4    | 'INFO' | 0x494E464F                             |
| Compression type | 4    | 0      | Currently no compression               |
| RSVD             | 4    |        |                                        |
| Data size        | 4    |        | Size of the flat file information fork |

### Flat File Information Fork

| Description       | Size | Data             | Note                                                  |
|-------------------|------|------------------|-------------------------------------------------------|
| Platform          | 4    | 'AMAC' or 'MWIN' | Operating system used                                 |
| Type signature    | 4    |                  | File type signature                                   |
| Creator signature | 4    |                  | File creator signature                                |
| Flags             | 4    |                  |                                                       |
| Platform flags    | 4    |                  |                                                       |
| RSVD              | 32   |                  |                                                       |
| Create date       | 8    |                  | See description for the File Create Date field (208)  |
| Modify date       | 8    |                  | See description for the File Modify Date field (209)  |
| Name script       | 2    |                  |                                                       |
| Name size         | 2    |                  |                                                       |
| Name              | size |                  | Maximum 128 characters                                |

### Flat File Data Fork Header

| Description      | Size | Data   | Note                      |
|------------------|------|--------|---------------------------|
| Fork type        | 4    | 'DATA' | 0x44415441                |
| Compression type | 4    | 0      | Currently no compression  |
| RSVD             | 4    |        |                           |
| Data size        | 4    |        | Actual file content size  |

---

## Transaction Fields

There are 3 predefined field data types: **integer**, **string** and **binary**. If field data does not fit in the first two categories, it is sent as binary data and interpreted by the receiving machine. Some of the binary fields are currently used as strings. All integer fields are treated as unsigned, and can be sent as 16 or 32-bit numbers. This is determined by evaluation of the number itself. Namely, if integer can be represented using only 2 bytes, it is sent as such. In the case when the number is greater than 2^16, it's sent as 32-bit number. String fields currently use 8-bit ASCII character set.

### Error Text (100)
- **Constant:** myField_ErrorText

### Data (101)
- **Constant:** myField_Data
- **Type:** Binary

### User Name (102)
- **Constant:** myField_UserName
- **Type:** String

### User ID (103)
- **Constant:** myField_UserID
- **Type:** Integer

### User Icon ID (104)
- **Constant:** myField_UserIconID
- **Type:** Integer

### User Login (105)
- **Constant:** myField_UserLogin
- **Type:** String

### User Password (106)
- **Constant:** myField_UserPassword
- **Type:** String

### Reference Number (107)
- **Constant:** myField_RefNum
- **Type:** Integer

### Transfer Size (108)
- **Constant:** myField_TransferSize
- **Type:** Integer

### Chat Options (109)
- **Constant:** myField_ChatOptions
- **Type:** Integer

### User Access (110)
- **Constant:** myField_UserAccess
- **Type:** Binary

This field is represented as 64-bit bitmap. The specific bit meaning is described in the Access Privileges section of this document.

### User Alias (111)
- **Constant:** myField_UserAlias

### User Flags (112)
- **Constant:** myField_UserFlags
- **Type:** Integer

User flags field is a bitmap with the following values:

| Bit | Value | Description                       |
|-----|-------|-----------------------------------|
| 0   | 1     | User is away                      |
| 1   | 2     | User is admin (or disconnected?)  |
| 2   | 4     | User refuses private messages     |
| 3   | 8     | User refuses private chat         |

### Options (113)
- **Constant:** myField_Options
- **Type:** Integer

### Chat ID (114)
- **Constant:** myField_ChatID
- **Type:** Integer

### Chat Subject (115)
- **Constant:** myField_ChatSubject
- **Type:** String

### Waiting Count (116)
- **Constant:** myField_WaitingCount
- **Type:** Integer

### Server Agreement (150)
- **Constant:** myField_ServerAgreement

### Server Banner (151)
- **Constant:** myField_ServerBanner
- **Type:** Binary

### Server Banner Type (152)
- **Constant:** myField_ServerBannerType
- **Type:** Integer

This field can have one of the following values:

| Value | Equivalent Value | Description |
|-------|------------------|-------------|
| 1     | 'URL '           | URL link    |
| 3     | 'JPEG'           | JPEG file   |
| 4     | 'GIFf'           | GIF file    |
| 5     | 'BMP '           | BMP file    |
| 6     | 'PICT'           | PICT file   |

### Server Banner URL (153)
- **Constant:** myField_ServerBannerUrl
- **Type:** Binary

### No Server Agreement (154)
- **Constant:** myField_NoServerAgreement
- **Type:** Integer

The value of this field is 1 if there is no agreement to be sent.

### Version (160)
- **Constant:** myField_Vers
- **Type:** Integer

### Community Banner ID (161)
- **Constant:** myField_CommunityBannerID
- **Type:** Integer

### Server Name (162)
- **Constant:** myField_ServerName
- **Type:** Binary

### File Name with Info (200)
- **Constant:** myField_FileNameWithInfo
- **Type:** Binary

File name with info field content is presented in this structure:

| Description | Size | Data | Note                     |
|-------------|------|------|--------------------------|
| Type        | 4    |      | Folder ('fldr') or other |
| Creator     | 4    |      |                          |
| File size   | 4    |      |                          |
|             | 4    |      | Reserved?                |
| Name script | 2    |      |                          |
| Name size   | 2    |      |                          |
| Name data   | size |      |                          |

### File Name (201)
- **Constant:** myField_FileName
- **Type:** String

### File Path (202)
- **Constant:** myField_FilePath
- **Type:** Binary

### File Resume Data (203)
- **Constant:** myField_FileResumeData
- **Type:** Binary

File resume data field content is presented in this structure:

| Description      | Size | Data   | Note        |
|------------------|------|--------|-------------|
| Format           | 4    | 'RFLT' |             |
| Version          | 2    | 1      | Currently 1 |
| RSVD             | 34   |        | ?           |
| Fork count       | 2    | 2      | Currently 2 |
| Fork info list…  |      |        |             |

Fork info list contains one or more records with the following structure:

| Description | Size | Data   | Note              |
|-------------|------|--------|-------------------|
| Fork        | 4    | 'DATA' |                   |
| Data size   | 4    |        | Current file size |
| RSVD A      | 4    |        | ?                 |
| RSVD B      | 4    |        | ?                 |

### File Transfer Options (204)
- **Constant:** myField_FileXferOptions
- **Type:** Integer

### File Type String (205)
- **Constant:** myField_FileTypeString
- **Type:** String

### File Creator String (206)
- **Constant:** myField_FileCreatorString
- **Type:** String

### File Size (207)
- **Constant:** myField_FileSize
- **Type:** Integer

### File Create Date (208)
- **Constant:** myField_FileCreateDate
- **Type:** Binary

| Description  | Size | Data | Note |
|--------------|------|------|------|
| Year         | 2    |      |      |
| Milliseconds | 2    |      |      |
| Seconds      | 4    |      |      |

### File Modify Date (209)
- **Constant:** myField_FileModifyDate
- **Type:** Binary

| Description  | Size | Data | Note |
|--------------|------|------|------|
| Year         | 2    |      |      |
| Milliseconds | 2    |      |      |
| Seconds      | 4    |      |      |

### File Comment (210)
- **Constant:** myField_FileComment
- **Type:** String

### File New Name (211)
- **Constant:** myField_FileNewName
- **Type:** String

### File New Path (212)
- **Constant:** myField_FileNewPath
- **Type:** Binary

### File Type (213)
- **Constant:** myField_FileType
- **Type:** Binary

| Description | Size | Data | Note                             |
|-------------|------|------|----------------------------------|
| File type   | 4    |      | File type code ('fldr' or other) |

### Quoting Message (214)
- **Constant:** myField_QuotingMsg
- **Type:** Binary

### Automatic Response (215)
- **Constant:** myField_AutomaticResponse
- **Type:** String

### Folder Item Count (220)
- **Constant:** myField_FldrItemCount
- **Type:** Integer

### User Name with Info (300)
- **Constant:** myField_UserNameWithInfo
- **Type:** Binary

| Description    | Size | Data | Note             |
|----------------|------|------|------------------|
| User ID        | 2    |      |                  |
| Icon ID        | 2    |      |                  |
| User flags     | 2    |      |                  |
| User name size | 2    |      |                  |
| User name      | size |      | User name string |

### News Category GUID (319)
- **Constant:** myField_NewsCatGUID

### News Category List Data (320)
- **Constant:** myField_NewsCatListData
- **Type:** Binary

News category list data field contains this structure (for client/server version 1.5):

| Description   | Size | Data         | Note                                              |
|---------------|------|--------------|---------------------------------------------------|
| Type          | 1    | 1, 10 or 255 | Category folder (1), category (10) or other (255) |
| Category name | rest |              |                                                   |

### News Article List Data (321)
- **Constant:** myField_NewsArtListData
- **Type:** Binary

News article list data field contains this structure:

| Description        | Size | Data | Note                            |
|--------------------|------|------|---------------------------------|
| ID                 | 4    |      |                                 |
| Article count      | 4    |      | Number of articles              |
| Name size          | 1    |      |                                 |
| Name               | size |      | Name string                     |
| Description size   | 1    |      |                                 |
| Description        | size |      | Description string              |
| List of articles…  |      |      | Optional (if article count > 0) |

List of articles contains:

| Description       | Size | Data | Note                                                         |
|-------------------|------|------|--------------------------------------------------------------|
| Article ID        | 4    |      |                                                              |
| Time stamp        | 8    |      | Year (2 bytes), milliseconds (2 bytes) and seconds (4 bytes) |
| Parent article ID | 4    |      |                                                              |
| Article flags     | 4    |      |                                                              |
| Flavor count      | 2    |      |                                                              |
| Title size        | 1    |      |                                                              |
| Title             | size |      | Title string                                                 |
| Poster size       | 1    |      |                                                              |
| Poster            | size |      | Poster string                                                |
| Flavor list…      |      |      | Optional (if flavor count > 0)                               |

Flavor list has the following structure:

| Description  | Size | Data | Note             |
|--------------|------|------|------------------|
| Flavor size  | 1    |      |                  |
| Flavor text  | size |      | MIME type string |
| Article size | 2    |      |                  |

### News Category Name (322)
- **Constant:** myField_NewsCatName
- **Type:** String

### News Category List Data 1.5 (323)
- **Constant:** myField_NewsCatListData15
- **Type:** Binary

News category list data field contains this structure:

| Description | Size | Data   | Note                       |
|-------------|------|--------|----------------------------|
| Type        | 2    | 2 or 3 | Bundle (2) or category (3) |

If type value indicates a bundle, what follows the type is:

| Description | Size | Data | Note |
|-------------|------|------|------|
| Count       | 2    |      |      |
| Name size   | 1    |      |      |
| Name data   | size |      |      |

In the case of a category type, type value is followed by:

| Description | Size | Data | Note |
|-------------|------|------|------|
| Count       | 2    |      |      |
| GUID        |      |      |      |
| Add SN      | 4    |      |      |
| Delete SN   | 4    |      |      |
| Name size   | 1    |      |      |
| Name data   | size |      |      |

### News Path (325)
- **Constant:** myField_NewsPath
- **Type:** Binary

### News Article ID (326)
- **Constant:** myField_NewsArtID
- **Type:** Integer

### News Article Data Flavor (327)
- **Constant:** myField_NewsArtDataFlav
- **Type:** String

### News Article Title (328)
- **Constant:** myField_NewsArtTitle
- **Type:** String

### News Article Poster (329)
- **Constant:** myField_NewsArtPoster
- **Type:** String

### News Article Date (330)
- **Constant:** myField_NewsArtDate
- **Type:** Binary

| Description  | Size | Data | Note |
|--------------|------|------|------|
| Year         | 2    |      |      |
| Milliseconds | 2    |      |      |
| Seconds      | 4    |      |      |

### News Article – Previous Article (331)
- **Constant:** myField_NewsArtPrevArt
- **Type:** Integer

### News Article – Next Article (332)
- **Constant:** myField_NewsArtNextArt
- **Type:** Integer

### News Article Data (333)
- **Constant:** myField_NewsArtData
- **Type:** Binary

### News Article Flags (334)
- **Constant:** myField_NewsArtFlags
- **Type:** Integer

### News Article – Parent Article (335)
- **Constant:** myField_NewsArtParentArt
- **Type:** Integer

### News Article – First Child Article (336)
- **Constant:** myField_NewsArt1stChildArt
- **Type:** Integer

### News Article – Recursive Delete (337)
- **Constant:** myField_NewsArtRecurseDel
- **Type:** Integer

---

## Access Privileges

The following is the list of access privileges currently employed by the application. There are 3 types of access privileges: **general**, **folder** and **bundle**. Folder privileges are set per folder. Bundle access is related to the logical grouping of the information. General access privileges are used to set privileges for a user.

| Bit | Name                   | Constant               | Type            |
|-----|------------------------|------------------------|-----------------|
| 0   | Delete File            | myAcc_DeleteFile       | folder          |
| 1   | Upload File            | myAcc_UploadFile       | folder, general |
| 2   | Download File          | myAcc_DownloadFile     | folder, general |
| 3   | Rename File            | myAcc_RenameFile       |                 |
| 4   | Move File              | myAcc_MoveFile         |                 |
| 5   | Create Folder          | myAcc_CreateFolder     | folder          |
| 6   | Delete Folder          | myAcc_DeleteFolder     | folder          |
| 7   | Rename Folder          | myAcc_RenameFolder     |                 |
| 8   | Move Folder            | myAcc_MoveFolder       |                 |
| 9   | Read Chat              | myAcc_ReadChat         | general         |
| 10  | Send Chat              | myAcc_SendChat         | general         |
| 11  | Open Chat              | myAcc_OpenChat         |                 |
| 12  | Close Chat             | myAcc_CloseChat        |                 |
| 13  | Show in List           | myAcc_ShowInList       |                 |
| 14  | Create User            | myAcc_CreateUser       |                 |
| 15  | Delete User            | myAcc_DeleteUser       |                 |
| 16  | Open User              | myAcc_OpenUser         |                 |
| 17  | Modify User            | myAcc_ModifyUser       |                 |
| 18  | Change Own Password    | myAcc_ChangeOwnPass    |                 |
| 19  | Send Private Message   | myAcc_SendPrivMsg      |                 |
| 20  | News Read Article      | myAcc_NewsReadArt      | bundle, general |
| 21  | News Post Article      | myAcc_NewsPostArt      | general, bundle |
| 22  | Disconnect User        | myAcc_DisconUser       | general         |
| 23  | Cannot be Disconnected | myAcc_CannotBeDiscon   |                 |
| 24  | Get Client Info        | myAcc_GetClientInfo    | general         |
| 25  | Upload Anywhere        | myAcc_UploadAnywhere   |                 |
| 26  | Any Name               | myAcc_AnyName          | general         |
| 27  | No Agreement           | myAcc_NoAgreement      |                 |
| 28  | Set File Comment       | myAcc_SetFileComment   | folder          |
| 29  | Set Folder Comment     | myAcc_SetFolderComment | folder          |
| 30  | View Drop Boxes        | myAcc_ViewDropBoxes    |                 |
| 31  | Make Alias             | myAcc_MakeAlias        | folder          |
| 32  | Broadcast              | myAcc_Broadcast        | general         |
| 33  | News Delete Article    | myAcc_NewsDeleteArt    | bundle          |
| 34  | News Create Category   | myAcc_NewsCreateCat    | bundle          |
| 35  | News Delete Category   | myAcc_NewsDeleteCat    | bundle          |
| 36  | News Create Folder     | myAcc_NewsCreateFldr   | bundle          |
| 37  | News Delete Folder     | myAcc_NewsDeleteFldr   | bundle          |

---

## Download Folder Actions

These values are used to control folder upload/download process. When an application receives folder upload request, it is presented with the first applicable file. In the reply, application will specify an action to be performed:

### Send File (1)
- **Constant:** dlFldrAction_SendFile

Send file action starts the download of the file specified in the request. An additional TCP connection is opened to transfer this file, according to the protocol described in Download Folder (210) and Upload Folder (213) transaction.

### Resume File Download (2)
- **Constant:** dlFldrAction_ResumeFile

This action is similar to the send file action. It also starts the download, while providing the starting position in the file. An additional TCP connection is opened to transfer this file, in the same manner as for send file action.

### Next File (3)
- **Constant:** dlFldrAction_NextFile

Next file action notifies the receiver to send the name of the next file in a folder. Download of the current file is not initiated.

---

## Transaction Sequences

Hotline client contains few predefined transaction sequences in its current implementation.

### Login

After sending Login transaction (107), server will reply with Show Agreement (109). If user accepts the agreement, Hotline client sends Agreed transaction (121), followed by Get User Name List (300). Next, a Get File Name List (200) or Get News Category Name List (370) transaction is sent, depending on user preferences.

If server version is < 151, server will not send Show Agreement reply. In this case, after Login (107) transaction is sent, client sends Set Client User Info (304) transaction with only User Name (102) and User Icon ID (104) fields used, and does not expect a reply. Subsequently, it sends Get User Name List (300) request, followed by Get File Name List (200) or Get News Category Name List (370), depending on user preferences. After that, a banner is requested from HTTP server.

### Invite To Chat

When client receives Invite To Chat (113) transaction from the server with version < 151, and client has automatic response or reject chat flag set, Reject Chat Invite (114) transaction is sent back to the server.

---

## Tracker Interface

All string values use 8-bit ASCII character set encoding.

### Client Interface with Tracker

After establishing a connection with tracker, the following information is sent:

| Description  | Size | Data   | Note                        |
|--------------|------|--------|-----------------------------|
| Magic number | 4    | 'HTRK' |                             |
| Version      | 2    | 1 or 2 | Old protocol (1) or new (2) |

When version number is 2, request also includes additional data:

| Description   | Size | Data  | Note                         |
|---------------|------|-------|------------------------------|
| Login size    | 1    | >= 31 | Login string size            |
| Login         | size |       | Login string (padded with 0) |
| Password size | 1    | >= 31 | Password string size         |
| Password      | size |       | Password string (padded with 0) |

Reply received from the tracker starts with a header:

| Description  | Size | Data   | Note                        |
|--------------|------|--------|-----------------------------|
| Magic number | 4    | 'HTRK' | 0x4854524B                  |
| Version      | 2    | 1 or 2 | Old protocol (1) or new (2) |

Server information header follows:

| Description       | Size | Data | Note                                  |
|-------------------|------|------|---------------------------------------|
| Message type      | 2    | 1    | Sending list of servers               |
| Message data size | 2    |      | Remaining size of this request        |
| Number of servers | 2    |      | Number of servers in the server list  |
| Number of servers | 2    |      | Same as previous field                |
| Server list…      |      |      |                                       |

A record in the server list has the following structure:

| Description      | Size | Data | Note                                                |
|------------------|------|------|-----------------------------------------------------|
| IP address       | 4    |      | Server's IP address                                 |
| IP port number   | 2    |      | Server's IP port number                             |
| Number of users  | 2    |      | Number of users connected to this particular server |
|                  | 2    | 0    |                                                     |
| Name size        | 1    |      | Server's name string size                           |
| Name             | size |      | Server's name                                       |
| Description size | 1    |      | Server's description string size                    |
| Description      | size |      | Description of the server                           |

If the number of servers in the server list is less than number of servers specified in the server information header, client will expect an additional server information, starting with the new server information header. The field containing number of servers in the new header should have the same value as the previous one.

When a client is connected to the tracker over the HTTP tunneling protocol, the client does not send any request to the tracker, although it still expects a properly formatted reply. In this case establishing a connection to the tracker indicates a request for the server list.

### Server Interface with Tracker

Server sets up UDP port that is used to periodically send the following information to the trackers:

| Description      | Size | Data | Note                                                |
|------------------|------|------|-----------------------------------------------------|
|                  | 2    | 1    |                                                     |
| IP port number   | 2    |      | Server's listening UDP port number                  |
| Number of users  | 2    |      | Number of users connected to this particular server |
|                  | 2    | 0    |                                                     |
| Pass ID          | 4    |      | Random number generated by the server               |
| Name size        | 1    |      | Server's name string size                           |
| Name             | size |      | Server's name                                       |
| Description size | 1    |      | Server's description string size                    |
| Description      | size |      | Description of the server                           |

In the case when old (?) tracker is used, the additional information is formatted as follows:

| Description   | Size | Data | Note                                  |
|---------------|------|------|---------------------------------------|
| Password size | 1    |      | Server's tracker password string size |
| Password      | size |      | Server's tracker password             |

For a new version of the tracker:

| Description   | Size | Data | Note                                  |
|---------------|------|------|---------------------------------------|
| Login size    | 1    |      | Server's tracker login string size    |
| Login         | size |      | Server's tracker login                |
| Password size | 1    |      | Server's tracker password string size |
| Password      | size |      | Server's tracker password             |

---

## HTTP Tunneling

When client is unable to communicate with the server using plain TCP connection, HTTP tunneling can be utilized to access the Hotline server over an HTTP proxy. To accomplish this, the client creates two connections to the server. One would be used for sending, and other for receiving data. After these connections are open, the client begins transmitting standard HTTP requests. If HTTP proxy terminates connection while that connection is still in use, the client recreates them, and interrupted requests are resent.

### HTTP Requests

HTTP POST request is sent over sending, while GET request is sent over receiving connection.

**POST request:**
```
POST <address> HTTP/1.0\r\n
Proxy-Connection: Keep-Alive\r\n
Pragma: no-cache\r\n
Host: <host>\r\n
Content-Length: 999999999\r\n
Content-Type: hotline/protocol\r\n
\r\n
```

**Server reply to POST (when connection is about to be closed):**
```
HTTP/1.0 302 Found\r\n
Connection: close\r\n
Content-Length: 8\r\n
Content-Type: hotline/protocol\r\n
\r\n
```

Next 8 bytes are filled with 0 to indicate termination of a connection.

**GET request:**
```
GET <address> HTTP/1.0\r\n
Proxy-Connection: Keep-Alive\r\n
Pragma: no-cache\r\n
Host: <host>\r\n
Accept: hotline/protocol\r\n
\r\n
```

**Server's immediate reply to GET:**
```
HTTP/1.0 200 OK\r\n
Proxy-Connection: Keep-Alive\r\n
Content-Length: 999999999\r\n
Content-Type: hotline/protocol\r\n
\r\n
```

After this reply, server uses this connection to send data to the client.

Address used in these requests is standard URL address followed by the session ID, specified as the file in the root directory. Example:
```
http://tracker.com:5497/5555-5555-5555
```

Session ID is used in order to identify the client in the case of disconnect. Host name specified in the HTTP headers is in the form of standard domain name string, followed by the port number. Example:
```
tracker.com:5497
```

### Data Header

Additional header precedes every transaction that is sent over these two connections:

| Description | Size | Data | Note                                  |
|-------------|------|------|---------------------------------------|
| Data code   | 4    |      | Disconnect (0), data (1), padding (2) |
| Data size   | 4    |      |                                       |
| Data…       | size |      |                                       |

Data content depends on the data code specified:
- **Code 1 (http_Data):** Transaction data as described in this specification (includes tracker protocol)
- **Code 0:** Notifies the remote end of a pending disconnect
- **Code 2 (http_Padding):** Padding data to keep the connection alive; data content is discarded

---

## Global Server

### 1.1 Server Information

Hotline servers will be able to create an account on the global server by providing a unique **server name** (relatively short in size) and an **access password**. This information constitutes an account login information that will have to be provided in every subsequent access to the global server. At the time the account is created, the global server assigns the unique **server ID** to the server.

Global server will provide servers with the ability to store a predefined set of data fields:

| Data                  | Options                      | Note                               |
|-----------------------|------------------------------|------------------------------------|
| Server ID             |                              | Assigned by the global server      |
| Server name           |                              | Used as login                      |
| Access password       |                              |                                    |
| Server alias          |                              | Region specific alias              |
| Description           |                              |                                    |
| Classification        |                              |                                    |
| Icon                  |                              | Graphical icon                     |
| Rating                |                              |                                    |
| Public encryption key |                              |                                    |
| IP address            | Original, Current            | Include the port number            |
| Attributes            | Searchable, Allow rating     |                                    |
| Status flags          | Active, On-line              | Active or not, On-line or off-line |
| Number of users       |                              |                                    |
| Date                  | Account created, Last access |                                    |

### 1.2 Global Server Transactions

#### 1.2.1 Server Login

- **Initiator:** Server

This transaction is used every time the server logins to the global server. It must be the first transaction sent to the global server.

**Fields used in the request:**

| ID | Field Name            | Note                                          |
|----|-----------------------|-----------------------------------------------|
|    | Server name           |                                               |
|    | Access password       |                                               |
|    | New account indicator | Optional - Indicates if this is a new account |

**Fields used in the reply:** None

If server indicates that it creates a new account, and account with identical ID already exists in the database, or if a new account cannot be created for any other reason, the global server indicates these conditions with the proper error code.

#### 1.2.2 Update Server Information

- **Initiator:** Server

Update server information on the global server. All fields in this request are optional.

**Fields used in the request:**

| ID | Field Name      | Note                         |
|----|-----------------|------------------------------|
|    | Access password |                              |
|    | Server name     |                              |
|    | Server alias    |                              |
|    | Description     |                              |
|    | Classification  |                              |
|    | Icon            |                              |
|    | Attributes      |                              |
|    | Status flags    |                              |
|    | IP port number  | Hotline protocol port number |
|    | Number of users | Current number of users      |

**Fields used in the reply:** None

#### 1.2.3 Delete Server Account

- **Access:** Administrator
- **Initiator:** Client

Delete server account from the database.

**Fields used in the request:**

| ID | Field Name  | Note |
|----|-------------|------|
|    | Server name |      |

**Fields used in the reply:** None

#### 1.2.4 Rate Server

- **Initiator:** Client

**Fields used in the request:**

| ID | Field Name  | Note |
|----|-------------|------|
|    | Server name |      |
|    | Rating      |      |

**Fields used in the reply:** None

#### 1.2.5 Query Server Database

- **Initiator:** Client

Create a query for the server database. All fields in this request are optional. If client does not specify the search string, the list of all servers is returned.

**Fields used in the request:**

| ID | Field Name     | Note     |
|----|----------------|----------|
|    | Search string  | Optional |
|    | Classification | Optional |

**Fields used in the reply:**

| ID | Field Name  | Note                       |
|----|-------------|----------------------------|
|    | Server ID   |                            |
|    | Server ID…  | Optional - More server IDs |

#### 1.2.6 Get Server Information

- **Initiator:** Client

Get information about the specific server.

**Fields used in the request:**

| ID | Field Name | Note |
|----|------------|------|
|    | Server ID  |      |

**Fields used in the reply:**

| ID | Field Name         | Note                  |
|----|--------------------|-----------------------|
|    | Server name        |                       |
|    | Server alias       |                       |
|    | Description        |                       |
|    | Current IP address | Including port number |
|    | Classification     |                       |
|    | Icon               |                       |
|    | Status flags       |                       |
|    | Number of users    |                       |