# Courier

Your AI agents text you a question. You text back. They keep working.

```bash
curl -X POST https://api.relaystation.ai/v1/bridge/notify \
  -H 'X-Payment: <base64 EIP-3009 auth>' \
  -H 'Idempotency-Key: build-green-20260528' \
  -H 'Content-Type: application/json' \
  -d '{"channel":"telegram","message":"Build is green."}'
```

## What it is

The hidden cost of running coding agents today isn't the per-token price — it's being chained to your desk. You set Cursor or Claude Code in motion, you go for a walk, you come back four hours later, and the agent stopped at minute 12 because it needed a decision. Courier fixes this. Your agent texts you ("Found three failing tests after the refactor — skip them or fix?"), you reply with your decision from your phone, the agent unblocks and keeps working. All without you opening your laptop.

Three channels carry the traffic. Telegram is the default — short questions, decisions, quick status pings. Email handles long-form messages, attachments via Baton URL, and agent-to-agent coordination. SMS is the urgency tier — vibrate the phone right now, operator is AFK. The same primitive that delivers an agent's question to your phone delivers your reply back to the agent.

We never bother you. Sign up once via Telegram or OAuth, top up once via Stars, Stripe, or crypto wallet, set a per-agent spend cap, and we vanish into your messaging app. Friction surfaces only in-channel, never in a dashboard. No subscription, no minimum, no monthly anything. The product is the absence of friction.

## Pricing

From $0.005 per Telegram message above the daily free tier (5 messages per day free). Email is $0.01 per message above the 2-per-day free tier. SMS is $0.05 per message (no free tier — paid-only by design, since SMS carrier costs are real). Agent-to-agent traffic is free at the channel layer. [See full pricing →](/pricing)

## How it works

1. **Sign up.** Telegram via the bot's `/start` command, or OAuth via Google or GitHub from the dashboard. Top up via Telegram Stars (in-bot, four-pack catalog), Stripe (dashboard checkout), or x402 lodestone (per-call, no signup at all).
2. **Drop one MCP config line into your agent runtime.** Cursor, Claude Code, Codex, Cline, Continue — any MCP-aware agent client. One line, fourteen tools, full Relaystation surface.
3. **Your agent calls `notify_operator` or `ask_operator`.** The wire shape is one HTTPS POST with a payload and a payment header. The agent specifies channel (Telegram default).
4. **You reply from your phone.** Tap-reply in Telegram, hit Reply in Gmail, text back in Messages. Your reply routes back to the agent's poll loop; the agent unblocks and continues.

## Channels and MCP tools

Eleven Courier tools cover the surface: three `ask_operator_*` variants (Telegram, email, SMS — agent blocks for reply), three `notify_operator_*` variants (same channels, fire-and-forget), `message_agent` for agent-to-agent traffic, three address-management tools (`create_agent_address`, `list_my_agent_addresses`, `get_mailbox`), and the `set_bridge_active` toggle. All eleven sit alongside Relaystation's chassis tools (Baton pricing, webhook registration) on the same MCP server. [See per-tool reference →](/docs/mcp-tools)

## Privacy

Envelope only, never content. We see who sent a message, when, and how big — never the body text. Content scanning for upsell targeting is forbidden regardless of revenue payoff. Privacy isn't a feature; it's the brand.

## Differentiation

The wedge against everything else is that most alternatives are one-way only.

| Tool | Two-way? | Pay-per-call? | MCP-native? |
|---|---|---|---|
| Pushover | One-way push | Annual sub | No |
| ntfy | One-way push | Free / self-host | No |
| Slack / Discord webhook | One-way to channel | (varies) | No |
| AgentMail | Email-only, laptop-bound | (varies) | Partial |
| Twilio direct | DIY both ends | Monthly + per-msg | No |
| Telegram bot DIY | DIY reply routing | (free, your code) | No |
| **Courier** | **Yes — agent asks, you reply, agent unblocks** | **Yes — no subscription** | **Yes — one config line, fourteen tools** |

We're the only product where the complete loop — text-to-operator AND reply-back-to-agent — happens with one drop-in MCP server and pay-per-call economics.

## Next

[Channels & opt-in](/docs/channels) · [MCP tools reference](/docs/mcp-tools) · [Bridge on/off](/docs/bridge-toggle) · [Agent-to-agent](/docs/agent-to-agent) · [Pricing](/pricing) · [API reference](/api-reference)