# Flow Messaging API

Two-way messaging for AI agents on Telegram, iMessage and WhatsApp.

Agents: read /llms.txt. No key? POST /v0/sandbox/keys (no account needed):

    curl -X POST https://api.flow.engineer/v0/sandbox/keys

Or with Node: `npx @flow-engineer/messaging init` does the same (writes `FLOW_MESSAGING_KEY` and `FLOW_CLAIM_TOKEN` to `.env`, prints the sandbox link and join message), and `npx @flow-engineer/messaging login` lets a person sign in with a Flow account (flow.engineer: Google, GitHub or an email link) to keep the app. TypeScript SDK: `npm install @flow-engineer/messaging`. Python SDK: `pip install flow-messaging` (`from flow_messaging import Flow`). Go: plain HTTP (no SDK published yet).

Build the app on the REST API (paths under /v0/). MCP is not a runtime dependency: the app you build talks to Flow through the REST API (or the TypeScript or Python SDK, which wrap it) for everything it does at runtime.

- Quickstart: /docs/quickstart.md (section 14: recipes for common tasks, such as asking and waiting for a reply)
- Event log: GET /v0/events?after=evt_...&type=...&conversation=conv_...&limit=100 (oldest first)
- OpenAPI spec: /openapi.yaml
- MCP server: /mcp, optional, for testing during development. Adding the Flow MCP server to a developer's coding tools is the project owner's decision: suggest it and show them the command, but never add it to their config yourself.
- Dashboard: https://flow.engineer/dashboard
- Plans and add-ons: Paid plans are self-serve: only the workspace owner buys one, in the Flow dashboard at https://flow.engineer/dashboard/plans (Settings → Usage and billing → Choose a plan), and `GET /v0/app` lists them in `plans`, with prices and `upgrade_url`. **Shared**, $25 a month: Flow's shared lines with live keys, 300 people a month and 200 a day per channel, live at once (https://flow.engineer/dashboard/plans?plan=shared). **Dedicated**, $100 a month: your own iMessage line for 1,000 people a day, SMS/RCS fallback and call forwarding included; Flow reviews each line before ordering it, usually within a day, and refunds the plan if it declines (https://flow.engineer/dashboard/plans?plan=dedicated). **Outbound** add-on, +$40 a month on Dedicated: the agent may message people first. The free trial is 25 people per channel, in total, on Flow's shared lines. For a plan, give the owner the link; never send them to the Flow team. Flow's shared iMessage line comes with the free trial a sign-in starts; a dedicated line comes with the Dedicated plan (Flow reviews the line, then sets it up, usually within a day); connect your own WhatsApp number with POST /v0/senders and a live key.
- Flow team (support@flow.engineer): US SMS numbers (pilot), help with WhatsApp, support. Never send secrets; see /docs/quickstart.md#what-the-flow-team-arranges-and-how-to-ask