AI API

Chat completion. Auth: Authorization: Bearer <token> or x-api-key: <your-api-key>. Non-stream: JSON with choices[].message.content. Stream: SSE chunks with choices[].delta.content.

Version: 1.0
Base URL: https://api.b.ai
Legacy Compatible Base URL: https://api.bankofai.io
OpenAPI: 3.1.0

Authentication

Bearer Token

Type: HTTP Bearer token
Header: Authorization: Bearer <token>
Format: Use the same API key-style secret issued by the platform, for example sk-xxx
Example: Bearer sk-xxx

API Key

Type: API Key
Header: x-api-key: <your-api-key>
Note: The Chat Completions and Messages endpoints both accept either x-api-key or Authorization: Bearer <token>. In practice, both use the same platform-issued secret.

Endpoints

1. List Models

GET /v1/models

List available models. Auth: Bearer token.

Auth: Bearer Token or API Key (x-api-key)

Response 200:

{
  "object": "list",
  "success": true,
  "data": [
    {
      "id": "gpt-5.2",
      "object": "model",
      "created": 1626777600,
      "owned_by": "openai",
      "supported_endpoint_types": ["openai", "anthropic"]
    }
  ]
}

Status	Description
200	Success - list of models
400	Bad Request - invalid parameters or malformed body
401	Unauthorized - invalid or missing authentication
403	Forbidden - access denied, insufficient quota, or banned
429	Too Many Requests - rate limit exceeded
500	Internal Server Error

2. Chat Completions (OpenAI Compatible)

POST /v1/chat/completions

Accepts a list of messages and returns a model-generated response. Supports both single-turn and multi-turn conversations. Responses can be streamed (SSE) or returned as a single JSON object.

Auth: Bearer Token

Request Body

Parameter	Type	Required	Description
`model`	string	Yes	ID of the model to use (e.g. `gpt-5.2`).
`messages`	array	Yes	List of messages in the conversation. See ChatMessage.
`stream`	boolean	No	If true, partial message deltas will be sent as server-sent events. Default `false`.
`max_tokens`	integer	No	Maximum number of tokens that can be generated in the completion.
`temperature`	number	No	Sampling temperature between 0 and 2. Higher = more random. Default `1`.
`top_p`	number	No	Nucleus sampling: consider tokens with top_p probability mass. Default `1`.
`stop`	string \| string[]	No	Up to 4 sequences where the API will stop generating.
`n`	integer	No	How many chat completion choices to generate. Default `1`.
`frequency_penalty`	number	No	-2.0 to 2.0. Penalize repeated tokens. Default `0`.
`presence_penalty`	number	No	-2.0 to 2.0. Penalize tokens that appear in the text so far. Default `0`.
`seed`	integer	No	Random seed for deterministic sampling (if supported by model).
`response_format`	object	No	Specify output format: `{ "type": "text" }` or `{ "type": "json_object" }` or `json_schema`.
`tools`	array	No	List of tools the model may call. See ChatTool.
`tool_choice`	string \| object	No	`"auto"`, `"none"`, `"required"`, or `{ "type": "function", "function": { "name": "..." } }`.
`user`	string	No	Optional end-user identifier for abuse monitoring.
`web_search_options`	object	No	Enables web search for supported models. See WebSearchOptions.

Request Example

{
  "model": "gpt-5.2",
  "messages": [
    { "role": "system", "content": "You are a helpful assistant." },
    { "role": "user", "content": "Hello" }
  ],
  "stream": false,
  "max_tokens": 1024,
  "temperature": 1
}

Response (Non-stream)

{
  "id": "chatcmpl-xxx",
  "object": "chat.completion",
  "created": 1677652288,
  "model": "gpt-5.2",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Hello! How can I help you?",
        "refusal": null,
        "annotations": []
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 12,
    "completion_tokens": 8,
    "total_tokens": 20,
    "prompt_tokens_details": { "cached_tokens": 0, "audio_tokens": 0 },
    "completion_tokens_details": {
      "reasoning_tokens": 0,
      "audio_tokens": 0,
      "accepted_prediction_tokens": 0,
      "rejected_prediction_tokens": 0
    }
  }
}

Response (Stream)

Each SSE chunk has object: "chat.completion.chunk" with choices[].delta.content containing incremental text. The final chunk includes usage and finish_reason.

Status	Description
200	Success
400	Bad Request - invalid parameters, malformed body, or invalid request
401	Unauthorized - invalid or missing authentication
403	Forbidden - access denied, insufficient quota, or model access restricted
429	Too Many Requests - rate limit exceeded
500	Internal Server Error
502	Bad Gateway - upstream service error
503	Service Unavailable - overloaded or no available channel

3. Messages (Claude Compatible)

POST /v1/messages

Accepts a list of messages and returns a model-generated response. Supports both single-turn and multi-turn conversations. Authenticate via x-api-key header or Bearer token. Responses can be streamed (SSE) or returned as a single JSON object.

Auth: API Key (x-api-key) or Bearer Token

Request Body

Parameter	Type	Required	Description
`model`	string	Yes	ID of the model (e.g. `claude-sonnet-4.6`, `claude-opus-4.6`, `claude-haiku-4.5`).
`max_tokens`	integer	Yes	Maximum number of tokens to generate. Different models have different maximum values.
`messages`	array	Yes	Input messages. Alternating user/assistant turns. Limit: 100,000 messages. See MessagesMessageItem.
`system`	string \| array	No	System prompt. Can be a plain string or an array of text blocks (for `cache_control`).
`stream`	boolean	No	Whether to stream the response using SSE. Default `false`.
`temperature`	number	No	Randomness (0.0 - 1.0). Use ~0.0 for analytical tasks, ~1.0 for creative tasks. Default `1`.
`top_p`	number	No	Nucleus sampling. Default `1`.
`top_k`	integer	No	Only sample from the top K options. Default disabled.
`stop_sequences`	string[]	No	Custom text sequences that cause the model to stop generating.
`metadata`	object	No	Request metadata. Supports `user_id` (opaque identifier).
`thinking`	object	No	Extended thinking config. See ThinkingConfig.
`tools`	array	No	Tool definitions the model may use. See Tool.
`tool_choice`	object	No	How the model should use tools: `auto`, `any`, `tool`, or `none`.

Request Example

{
  "model": "claude-sonnet-4.6",
  "max_tokens": 1024,
  "messages": [
    { "role": "user", "content": "Hello, Claude!" }
  ],
  "system": "You are a helpful assistant.",
  "temperature": 1.0
}

Response (Non-stream)

{
  "id": "chatcmpl-xxx",
  "type": "message",
  "role": "assistant",
  "content": [
    { "type": "text", "text": "Hello! How can I help you?" }
  ],
  "stop_reason": "end_turn",
  "model": "claude-sonnet-4.6",
  "usage": {
    "input_tokens": 4,
    "cache_creation_input_tokens": 0,
    "cache_read_input_tokens": 0,
    "output_tokens": 12,
    "claude_cache_creation_5_m_tokens": 0,
    "claude_cache_creation_1_h_tokens": 0
  }
}

Response (Stream - SSE Events)

Stream responses emit the following event types:

Event Type	Description	Key Fields
`message_start`	Initial message metadata	`message` (id, model, role, usage)
`content_block_start`	New content block begins	`index`, `content_block` (type, text)
`content_block_delta`	Incremental content	`index`, `delta` (type: `text_delta`, text)
`content_block_stop`	Content block ends	`index`
`message_stop`	Message complete	-

Status	Description
200	Success
400	Bad Request - invalid parameters, malformed body, or invalid request
401	Unauthorized - invalid or missing API key
403	Forbidden - access denied, insufficient quota, or model access restricted
429	Too Many Requests - rate limit exceeded
500	Internal Server Error
502	Bad Gateway - upstream service error
503	Service Unavailable - overloaded or no available channel

Data Models

ChatMessage

Field	Type	Required	Description
`role`	string	Yes	`"system"`, `"user"`, `"assistant"`, or `"tool"`
`content`	string	Yes	Message content. For tool role, the result of the tool call.
`name`	string	No	Optional name for the message author.
`tool_call_id`	string	No	When role is `"tool"`, the ID of the tool call this result is for.
`tool_calls`	array	No	When role is `"assistant"` and the model called tools. Array of `{ id, type, function: { name, arguments } }`.

MessagesMessageItem

Field	Type	Required	Description
`role`	string	Yes	`"user"` or `"assistant"` (no `"system"` - use top-level `system` parameter).
`content`	string \| array	Yes	Text string or array of content blocks (text, image, tool_use, tool_result).

Content Block Types (Messages API)

TextBlockParam

{ "type": "text", "text": "Hello, Claude!", "cache_control": { "type": "ephemeral" } }

ImageBlockParam

Base64 source:

{
  "type": "image",
  "source": {
    "type": "base64",
    "media_type": "image/jpeg",
    "data": "/9j/4AAQSkZJRg..."
  }
}

URL source:

{
  "type": "image",
  "source": {
    "type": "url",
    "url": "https://example.com/image.jpg"
  }
}

Supported media types: image/jpeg, image/png, image/gif, image/webp

ToolUseBlockParam (from assistant)

{
  "type": "tool_use",
  "id": "toolu_01D7FLrfh4GYq7yT1ULFeyMV",
  "name": "get_stock_price",
  "input": { "ticker": "AAPL" }
}

ToolResultBlockParam (from user)

{
  "type": "tool_result",
  "tool_use_id": "toolu_01D7FLrfh4GYq7yT1ULFeyMV",
  "content": "259.75 USD",
  "is_error": false
}

ThinkingConfig

Enable extended thinking to let Claude show its reasoning process.

Enabled:

{ "type": "enabled", "budget_tokens": 1024 }

budget_tokens: Must be >= 1024 and less than max_tokens.

Disabled:

{ "type": "disabled" }

Tool (Anthropic)

{
  "name": "get_stock_price",
  "description": "Get the current stock price for a given ticker symbol.",
  "input_schema": {
    "type": "object",
    "properties": {
      "ticker": { "type": "string" }
    },
    "required": ["ticker"]
  }
}

ToolChoice (Anthropic)

Type	Description
`{ "type": "auto" }`	Model decides whether to use tools. Supports `disable_parallel_tool_use`.
`{ "type": "any" }`	Model will use any available tool. Supports `disable_parallel_tool_use`.
`{ "type": "tool", "name": "..." }`	Model will use the specified tool. Supports `disable_parallel_tool_use`.
`{ "type": "none" }`	Model will not use tools.

ChatTool

{
  "type": "function",
  "function": {
    "name": "get_weather",
    "description": "Get weather for a location",
    "parameters": {
      "type": "object",
      "properties": {
        "location": { "type": "string" }
      },
      "required": ["location"]
    }
  }
}

WebSearchOptions

Field	Type	Description
`search_context_size`	string	`"low"`, `"medium"`, or `"high"` - how much context window for web search results.
`user_location`	object	Approximate user location (country ISO 3166-1 alpha-2, city, region, timezone).

ChatResponseFormat

Field	Type	Description
`type`	string	`"text"` or `"json_object"`
`json_schema`	object	When type is `json_schema`, optional schema for the output.

Error Response

All error responses follow this format:

{
  "error": {
    "message": "Error message",
    "type": "invalid_request_error",
    "param": null,
    "code": null
  }
}

Field	Type	Description
`message`	string	Error message
`type`	string	Error type (e.g. `invalid_request_error`)
`param`	string \| null	Related parameter
`code`	string \| null	Error code

AI API

Authentication​

Bearer Token​

API Key​

Endpoints​

1. List Models​

2. Chat Completions (OpenAI Compatible)​

Request Body​

Request Example​

Response (Non-stream)​

Response (Stream)​

3. Messages (Claude Compatible)​

Request Body​

Request Example​

Response (Non-stream)​

Response (Stream - SSE Events)​

Data Models​

ChatMessage​

MessagesMessageItem​

Content Block Types (Messages API)​

TextBlockParam​

ImageBlockParam​

ToolUseBlockParam (from assistant)​

ToolResultBlockParam (from user)​

ThinkingConfig​

Tool (Anthropic)​

ToolChoice (Anthropic)​

ChatTool​

WebSearchOptions​

ChatResponseFormat​

Error Response​

Authentication

Bearer Token

API Key

Endpoints

1. List Models

2. Chat Completions (OpenAI Compatible)

Request Body

Request Example

Response (Non-stream)

Response (Stream)

3. Messages (Claude Compatible)

Request Body

Request Example

Response (Non-stream)

Response (Stream - SSE Events)

Data Models

ChatMessage

MessagesMessageItem

Content Block Types (Messages API)

TextBlockParam

ImageBlockParam

ToolUseBlockParam (from assistant)

ToolResultBlockParam (from user)

ThinkingConfig

Tool (Anthropic)

ToolChoice (Anthropic)

ChatTool

WebSearchOptions

ChatResponseFormat

Error Response