API Overview

Claude Code Router Server provides a complete HTTP API with support for:

• Messages API: Anthropic Claude Messages (POST /v1/messages)
• Chat Completions API: OpenAI Chat Completions (POST /v1/chat/completions)
• Responses API: OpenAI Responses (POST /v1/responses)
• FIM Completions API: Fill-in-the-middle (POST /v1/fim/completions; separate pipeline)
• Models API: OpenAI-compatible listing of routable models
• Configuration API: Read and update server configuration
• Logs API: View and manage service logs
• Tools API: Calculate token counts

All four LLM POST protocols above are first-class inbound routes. Chat protocols share the Unified chat pipeline; FIM uses its own pipeline. The response always matches the inbound client protocol.

Basic Information

Base URL: http://localhost:3456

Authentication: API key via Authorization: Bearer or x-api-key

curl -H "x-api-key: your-api-key" http://localhost:3456/api/config

API Endpoints

Messages

Endpoint	Method	Description
/v1/messages	POST	Send message (compatible with Anthropic API)
/v1/messages/count_tokens	POST	Count tokens in messages
/v1/chat/completions	POST	OpenAI Chat Completions (alias: /chat/completions)
/v1/responses	POST	OpenAI Responses (alias: /responses)
/v1/fim/completions	POST	FIM Completions (alias: /fim/completions)
/v1/models	GET	List routable models (alias: /models)
/v1/models/{id}	GET	Single model info

Configuration Management

Endpoint	Method	Description
/api/config	GET	Get current configuration
/api/config	POST	Update configuration
/api/transformers	GET	Get list of available transformers

Log Management

Endpoint	Method	Description
/api/logs/files	GET	Get list of log files
/api/logs	GET	Get log content
/api/logs	DELETE	Clear logs

Service Management

Endpoint	Method	Description
/api/restart	POST	Restart service
/ui	GET	Web management interface
/ui/	GET	Web management interface (redirect)

Authentication

API Key Authentication

Add API Key in request header:

curl -X POST http://localhost:3456/v1/messages \
  -H "x-api-key: your-api-key" \
  -H "content-type: application/json" \
  -d '...'

Streaming Responses

Messages, Chat Completions, Responses, and FIM support Server-Sent Events when stream: true. Each route emits its inbound client protocol:

• Messages → Anthropic SSE (message_start / content_block_delta / …)
• Chat Completions → chat.completion.chunk records ending in [DONE]
• Responses → ordered response.* events ending in response.completed / response.failed
• FIM → inbound FIM wire (v1: Codestral/Mistral-shaped chunks)

curl -X POST http://localhost:3456/v1/messages \
  -H "x-api-key: your-api-key" \
  -H "content-type: application/json" \
  -d '{"stream": true, ...}'

Example Anthropic Messages stream:

event: message_start
data: {"type":"message_start","message":{...}}

event: content_block_delta
data: {"type":"content_block_delta","delta":{"type":"text_delta","text":"Hello"}}

event: message_stop
data: {"type":"message_stop"}