# Arc — Developer Platform (API & CLI)

> Read-only /v1 REST API and the arc CLI give an AI agent (or a developer) secure, company-scoped access to a startup's financial data — cash management, treasury, payments, invoices, cards, accounting connections. Authenticate with an API key (arc_sk_…); the CLI ships agent skills (arc skills install) that teach an agent when and how to use it.

For exact response shapes, run `arc openapi` (offline) or fetch `https://api.arc.tech/v1/openapi.json`. The surface is read-only; writes (money movement) are out of scope for /v1 today.

## Table of Contents

- [Arc Developer Docs](https://docs.joinarc.com/docs.md): Programmatic, read-only access to your Arc financial data — API, CLI, and AI agents.
- [Connect your AI agent](https://docs.joinarc.com/getting-started/connect-your-agent.md): Give an AI agent secure, read-only access to your Arc financial data through the arc CLI.
- [API](https://docs.joinarc.com/api/overview.md): The Arc /v1 REST API — authentication, resources, and conventions.
- [CLI](https://docs.joinarc.com/cli/overview.md): The arc command-line tool — install, authenticate, and the available commands.
- [Agent skills](https://docs.joinarc.com/cli/skills.md): The bundled agent skills that teach an AI agent when and how to use the arc CLI.
- [MCP](https://docs.joinarc.com/mcp/overview.md): Connecting no-shell AI assistants to Arc via the Model Context Protocol (coming soon).