API Overview

Base URL

https://api.a21e.com

All API endpoints are versioned under /v1/.

Authentication

Include your API key in the Authorization header:

Authorization: Bearer a21e_sk_your_api_key_here

Get an API key from Settings > API Keys.

Request format

All request bodies use JSON:

curl -X POST https://api.a21e.com/v1/rpc \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"method": "intent.submit", "params": {"input": "Hello"}}'

Response format

Responses are JSON with standard HTTP status codes:

Status	Meaning
`200`	Success
`201`	Created
`400`	Bad request (invalid parameters)
`401`	Unauthorized (missing or invalid API key)
`402`	Insufficient credits
`404`	Resource not found
`429`	Rate limited
`500`	Internal server error

Error responses include a message:

{
  "error": "INSUFFICIENT_CREDITS",
  "message": "Your credit balance is 0."
}

Rate limits

Endpoint	Limit
Intent submission	60 requests/minute
Chat completions	60 requests/minute
Read endpoints	120 requests/minute

Rate-limited responses return 429 with a Retry-After header.

Endpoints

The API has two main entry points:

JSON-RPC (POST /v1/rpc) — the canonical endpoint for intent submission
REST endpoints — resource-specific endpoints for CRUD operations (sessions, messages, memory, etc.)
OpenAI-compatible (POST /v1/chat/completions) — drop-in replacement for OpenAI SDK

Explore the full API in the sidebar, or try endpoints in the interactive playground.

Getting Started

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API Overview

Base URL

Authentication

Request format

Response format

Rate limits

Endpoints

​Base URL

​Authentication

​Request format

​Response format

​Rate limits

​Endpoints

Base URL

Authentication

Request format

Response format

Rate limits

Endpoints