docs/API_CAPABILITIES.md

API Capabilities

Supported

• OpenAI-compatible POST /v1/chat/completions
• OpenAI-compatible POST /v1/responses
• OpenAI-compatible GET /v1/models
• Non-stream responses with:
  • plain assistant text
  • assistant tool_calls
• Responses API outputs with:
  • output_text
  • function_call, apply_patch_call, shell_call, local_shell_call
• Stream responses with:
  • delta.content
  • delta.tool_calls
• Responses API stream events:
  • response.output_text.delta
  • response.function_call_arguments.delta
• Multi-turn context via the messages array
• Tool request fields:
  • tools
  • tool_choice
  • assistant history tool_calls
  • tool role history tool_call_id
• Automatically derived *-thinking public models, for example:
  • claude-sonnet-4.6
  • claude-sonnet-4.6-thinking
• Bearer token auth via Authorization: Bearer <API_KEY>

Behavior Notes

• Tool support is implemented through an internal prompt-and-parser bridge, not Cursor-native tool calling.
• Base models keep the current model name and enable tool use.
• *-thinking models map back to the same upstream base model, but also enable the internal thinking protocol.
• Thinking is an internal bridge capability only. The public OpenAI response does not expose a separate reasoning field.
• previous_response_id is supported with in-memory state only; restart clears history. For stateless use, include prior output items in input.

Not Supported

• Anthropic /v1/messages
• MCP orchestration
• Native upstream OpenAI tool execution
• Exposed reasoning/thinking response fields
• Local filesystem or OS command execution through the API
• Persisted Responses API storage or server-side conversations across restarts

Example: Non-Stream Tool Call

curl -X POST http://127.0.0.1:8002/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer 0000" \
  -d '{
    "model": "claude-sonnet-4.6",
    "stream": false,
    "messages": [
      {"role": "user", "content": "帮我查询北京天气"}
    ],
    "tools": [
      {
        "type": "function",
        "function": {
          "name": "get_weather",
          "description": "Get current weather",
          "parameters": {
            "type": "object",
            "properties": {
              "city": {"type": "string"}
            },
            "required": ["city"]
          }
        }
      }
    ]
  }'

Example: Thinking Model

curl -X POST http://127.0.0.1:8002/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer 0000" \
  -d '{
    "model": "claude-sonnet-4.6-thinking",
    "stream": true,
    "messages": [
      {"role": "user", "content": "先思考，再决定是否需要工具"}
    ],
    "tools": [
      {
        "type": "function",
        "function": {
          "name": "lookup",
          "parameters": {
            "type": "object",
            "properties": {
              "q": {"type": "string"}
            },
            "required": ["q"]
          }
        }
      }
    ]
  }'