What Is Agent Arbiter?

Agent Arbiter provides policy-controlled access to configured services for agents. Today it exposes that access through MCP and a client CLI; additional interfaces may be added later.

It gives agents a small surface for discovering what they are allowed to do, choosing an authorized context, and running one operation with deployment-owned configuration and policy.

The shape

• The core server composes config, loads plugins, exposes MCP and CLI access surfaces, and enforces the shared discovery flow.
• Operators configure accounts, credentials, service activation, and policies.
• Agents discover capabilities before selecting operations.
• Service plugins own their schemas, bootstrap templates, policy checks, and runtime behavior.

Current capabilities

• SMTP service plugin.
• IMAP service plugin.

Where to start

• New operator: start with Quickstart.
• Agent/tool user: start with Arbiter CLI Reference.
• Plugin author: start with Writing Plugins.