# Templa API versioning and errors

## Version 1

The administrative action API is available at POST https://templa.app/api/v1/mcp. POST /api/mcp remains a compatible alias for the existing local MCP bridge. Both require the same owner authentication and return Templa-API-Version: 1. This is an HTTP action API, not a remote MCP JSON-RPC transport.

Within v1, existing action names, input meaning and successful response fields remain compatible. Additive fields may be introduced. Breaking changes require a new major URL version. No current endpoint is deprecated. A planned retirement will be announced in this document with migration instructions and a minimum 90-day notice; affected responses will include the RFC 9745 Deprecation date and RFC 8594 Sunset HTTP date. Urgent security restrictions may apply sooner to protect accounts.

## Typed errors

Failures use application/json with ok:false, a stable code, human-readable message, resolution hint, HTTP status, api_version and docs link. The legacy error string is retained for existing clients. Validate against the ApiError component in /openapi.json. Missing credentials return 401, insufficient authority 403, invalid JSON 400, invalid arguments 422, missing resources 404, unsupported methods 405, rate limits 429 and unexpected failures 500. A failure never confirms a payment or completed mutation.

- [Templa OpenAPI schema](https://templa.app/openapi.json)
- [Authentication](https://templa.app/docs/auth.md)
- [Developer resources](https://templa.app/developers.md)