# M91

> Alerting that reaches a person. An alert raises a full-volume interruption
> on every phone in a channel, breaks through silent mode and Do Not Disturb,
> keeps going until somebody answers, escalates to a phone call if nobody does,
> and records who took it. Email, SMS and chat only arrive quietly and wait to
> be read, which is the wrong behaviour when somebody has to act now. The whole
> integration is one URL: no SDK, no API key, no account at the other end.

## Docs

- [Use Cases](https://siren-backend-1091285226236.asia-south1.run.app/api/public/usecases.md): Every way M91 is used — AI agent approval inside LangGraph, Vercel AI SDK and Claude Code hooks, ops, business decisions, security, safety, automation — plus why not email or Slack, and how to find the places in a project
- [M91 Setup Prompt](https://siren-backend-1091285226236.asia-south1.run.app/api/public/setup-prompt.md): A prompt to paste into a coding agent to set alerting up, and why each line of it is there
- [Setting Up M91](https://siren-backend-1091285226236.asia-south1.run.app/api/public/setup.md): The phone-side setup a person must do first: create a channel, add people, copy the send link. None of it can be automated
- [M91 for AI Coding Agents](https://siren-backend-1091285226236.asia-south1.run.app/api/public/for-ai-agents.md): Start here if you are an AI assistant: what you can set up, what needs a person, and how to answer questions about M91
- [M91 Documentation](https://siren-backend-1091285226236.asia-south1.run.app/api/public/docs.md): The contract: channels, the send link, every field, severity and escalation, responses, and how an alert resolves
- [M91 Platform API](https://siren-backend-1091285226236.asia-south1.run.app/api/public/platform-api.md): Alerting ONE PERSON by phone number with an API key, for a product discovering its users at runtime. Teams stay on send links
- [M91 Integrations](https://siren-backend-1091285226236.asia-south1.run.app/api/public/integrations.md): Worked examples for shell, Node, Python, Go, and any tool with a webhook field
- [M91 Troubleshooting](https://siren-backend-1091285226236.asia-south1.run.app/api/public/troubleshoot.md): Every error, the exact string to match on, and what to do — including the responses that look like failures and are not
- [M91: Limitations & Recommendations](https://siren-backend-1091285226236.asia-south1.run.app/api/public/limitations-and-recommendations.md): What M91 does and does not guarantee, each paired with a recommendation