# Telnyx Developers

> Developer entry point for Telnyx APIs, SDKs, and agent tooling. Telnyx
> is a carrier-owned communications platform: voice, messaging, numbers,
> verify, fax, AI inference, and edge compute.

## What this surface is for
- Building integrations against the Telnyx v2 REST API
- Using official SDKs (Node, Python, Go, Ruby, .NET, PHP, Java)
- Discovering OpenAPI specs, agent skills, and MCP tools
- Onboarding programmatic agents and bots

## Canonical docs and APIs
- Developer docs: https://developers.telnyx.com
- API reference: https://developers.telnyx.com/api
- OpenAPI discovery: https://telnyx.com/.well-known/openapi.json
- Public OpenAPI spec: https://raw.githubusercontent.com/team-telnyx/openapi/master/openapi/spec3.json
- API catalog: https://telnyx.com/.well-known/api-catalog
- Agent skills index: https://telnyx.com/.well-known/agent-skills/index.json
- MCP server card: https://telnyx.com/.well-known/mcp/server-card.json

## Authentication
- Bearer API key in Authorization header. See
  https://developers.telnyx.com/docs/api/v2/overview#authentication
- Create an API key via the portal or via the agent signup flow at
  https://telnyx.com/agent-signup.md

## Recovery and error contracts
- API errors return a top-level errors[] array with code, title, detail,
  and (where available) meta.url linking to error documentation. See
  https://developers.telnyx.com/docs/api/v2/overview#errors and
  https://developers.telnyx.com/docs/overview/errors
- Retry on HTTP 429 (respect Retry-After) and on documented transient
  5xx (502, 503, 504). Do not retry other 4xx responses.

## Agent fast path
- Single entry point: https://telnyx.com/agents/start
- Site-wide index: https://telnyx.com/llms.txt
- AI namespace index: https://telnyx.com/ai/llms.txt
- Markdown homepage: https://telnyx.com/index.md