# Integration notes

A few cross-cutting facts that will save you time when building against the API.

## Server-to-server only

The REST API does **not** send CORS headers, so browsers will block calls made directly from a web page. Call the API from your **backend**, and never ship a [Personal Access Token](/docs/authentication) to the client.

## No idempotency keys

The API has no idempotency mechanism. Re-sending an _execute_ request that already succeeded creates a **duplicate run** (and duplicate cost). To recover from a dropped response, prefer **polling the existing run** over re-submitting, and only retry submits you’re certain didn’t land. See [Async jobs](/docs/async-jobs).

## No webhooks

There is no way to register a callback for run completion — **poll** instead, on the returned `poll_interval_seconds`. See [Async jobs & polling](/docs/async-jobs).

## Versioning

The API is path-versioned under `/v1`. See [Versioning](/docs/versioning).

## Collections

An API request collection is available for **Postman** and **Bruno**, with a folder per resource — handy for exploring endpoints and building requests.

Note

There is no official SDK yet. Use the REST API directly (any HTTP client works), or the [MCP server](/docs/mcp) if you’re integrating with an AI agent.

## Quick reference

| Topic          | Value                                 |
| -------------- | ------------------------------------- |
| Base URL       | https://api.app.layer.ai/api          |
| Version prefix | /v1                                   |
| Auth           | Authorization: Bearer pat\_…          |
| Errors         | RFC 7807 application/problem+json     |
| Pagination     | cursor (limit ≤ 100)                  |
| Async          | 202 \+ poll (poll\_interval\_seconds) |