Sendblue

About

Sendblue gives software agents a phone number. It is a small API and CLI for sending text messages from code—iMessage when available, with SMS fallback. The interface is simple: sign in, choose a monthly limit, copy one instruction into your agent, and let the agent build.

There is no new inbox to learn. The CLI steers the API, so agents can inspect usage, test a number, send a message, and add messaging to an application using the same commands a person would.

Get started

1. Create an account.
2. Choose a message limit and buy an API key.
3. Copy the agent instructions into Codex, Claude, Cursor, or any terminal agent.
4. Your agent runs the CLI and builds the integration.

$ sendblue send --to +14155550123 --text "Your order is ready."
{ "status": "queued", "channel": "imessage" }

Pricing

Every plan includes the CLI, REST API, API-key controls, usage reporting, and automatic SMS fallback.

Limits are hard caps. Upgrade any time; no surprise overage bill.

What you copy to the agent

The dashboard fills in your private key. The rest is ordinary text that works in any coding agent.

Give this project text messaging with Sendblue.

1. Install the CLI:
   mkdir -p ~/.local/bin
   curl -fsSL https://sendblue.abstract.inc/cli/sendblue -o ~/.local/bin/sendblue
   chmod +x ~/.local/bin/sendblue

2. Authenticate with the API key I provide.
3. Run "sendblue doctor" before writing code.
4. Use "sendblue send --to <E.164> --text <message>" for manual tests.
5. For app code, POST JSON to https://sendblue.abstract.inc/api/v1/messages.

Never commit or print the API key. Ask before sending a real message.