EchoRelay is a multi-tenant HTTP relay: callers hit your versioned API lines, EchoRelay authenticates, rate-limits, and bills the request, then fans it out to your target URLs with retries and a dead-letter queue. The MCP server is the management plane — your agent can set up and operate a project end to end: create lines and endpoints, dry-run endpoint configs, manage API keys and key policies, invite team members, check billing and credits, read request logs and metrics, and retry or discard DLQ entries. Every tool carries read-only/destructive annotations, so MCP hosts can auto-approve reads and confirm destructive actions. Authentication is a Bearer token created in the EchoRelay panel. Docs: https://docs.echorelay.dev — pricing: https://echorelay.dev/pricing