Build an agent people can message

Relay sends messages to your backend as signed events. Your backend sends replies over HTTPS. You keep the model, tools, memory, and hosting. Relay runs the agent profile, conversation, delivery, media, and app.

Start with your coding agent

Copy this into your coding agent, then answer its questions.

Agent prompt

Build a Relay agent backend with me.

1. Fetch https://docs.relayapp.im/llms.txt and follow its agent instructions.
   If you cannot fetch it, stop and tell me.
2. Before writing code, ask me: (a) for my Agent Token (rly_live_..., shown
   once when I create the agent in the Relay app), and (b) whether my backend
   has a public HTTPS URL. Public URL: use signed webhooks. No public URL:
   use long polling.
3. Implement the loop: verify the token with GET /v1/agents/me, receive one
   message.received event, mark it read with POST /v1/chats/{id}/read,
   start POST /v1/chats/{id}/typing, reply with POST /v1/messages
   carrying a client-minted message_id, which is the send's idempotency key,
   and stop typing when done.

The contract is raw HTTPS and JSON at https://api.relayapp.im. Optional
published packages: @relaymessenger/sdk and @relaymessenger/cli. Import
nothing else.

Quickstart

Receive one message and send one reply.

Connect a runtime

Connect Claude Code, Codex, Hermes, OpenClaw, or your own runtime.

API reference

Read every endpoint, field, response, and status code.

Send a message

Every send uses an Agent Token. Mint the message_id yourself: it names the resulting message and is the send’s idempotency key.

curl -sS -X POST "https://api.relayapp.im/v1/messages" \
  -H "Authorization: Bearer $RELAY_AGENT_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "message_id": "msg_01k1m4q9vn2r7t9b4c6qdh8xwy",
    "chat_id": "cnv_01JZC7K4RQ",
    "parts": [{ "type": "text", "text": "Tomorrow at 2:00 PM works." }]
  }'

Relay returns 202 Accepted with { message_id, message }. One send is one message: text and media handed over together stay together as its ordered parts.

What Relay carries

Capability	Start here
Text, images, files, voice memos, and link previews	Send messages
Signed events and retries	Webhooks
Group conversations an agent takes part in	Group conversations
Delivery, Read, and typing state	Read receipts

Choose a start

Relay is in developer preview and ships through TestFlight. See current availability.

Start here

Send

Receive

Connect what you already run

Reference

Relay for Business

About Relay

Build an agent people can message

Start with your coding agent

Quickstart

Connect a runtime

API reference

Send a message

What Relay carries

Choose a start

​Start with your coding agent

Quickstart

Connect a runtime

API reference

​Send a message

​What Relay carries

​Choose a start

Start with your coding agent

Send a message

What Relay carries

Choose a start