# Channel3 auth.md

Channel3 authenticates developers and AI agents with API keys. This document describes how to obtain credentials and use them with the REST API and MCP server.

## Audience

Developers building AI shopping assistants, recommendation engines, product search, and agentic commerce integrations.

## Registration

1. Create a developer account: https://trychannel3.com/sign-up/developer
2. Generate an API key in the dashboard
3. Use the key in API and MCP requests

No OAuth flow is required for the public product data API. API keys are free to create. Every key includes 1,000 searches per month with no credit card required. Current limits: https://docs.trychannel3.com/pricing

## REST API

- **Base URL:** https://api.trychannel3.com/v1
- **Header:** `x-api-key: <your-api-key>`
- **OpenAPI:** https://api.trychannel3.com/openapi.json
- **Documentation:** https://docs.trychannel3.com

## MCP server

- **Endpoint:** https://mcp.trychannel3.com/
- **Transport:** Streamable HTTP
- **Header:** `Authorization: Bearer <your-api-key>`
- **Setup guide:** https://docs.trychannel3.com/mcp-overview

## CLI

Install the official Channel3 CLI:

```
npm i -g @channel3/cli
```

Documentation: https://docs.trychannel3.com/cli.md

This is the Channel3 API CLI. It is distinct from the shadcn CLI used to install Channel3 UI components.

## Rate limits

Quotas are enforced by API Gateway on https://api.trychannel3.com. Throttled requests receive HTTP 429 with a Retry-After header. Success responses do not currently send RFC 9239 RateLimit headers. This marketing origin (https://trychannel3.com) does not send RateLimit headers either.

## Credential use

- Keep API keys secret; do not commit them to source control.
- Rotate keys from the dashboard if a key is exposed.
- Contact support@trychannel3.com for enterprise deployments or dedicated credentials.

## Related discovery

- [API catalog](https://trychannel3.com/.well-known/api-catalog)
- [Developer agents.md](https://trychannel3.com/developers/agents.md)
- [llms.txt](https://trychannel3.com/llms.txt)
- [MCP server card](https://trychannel3.com/.well-known/mcp/server-card.json)
- [Deprecation policy](https://trychannel3.com/deprecation.md)
- [Contact](https://trychannel3.com/contact)