> ## Documentation Index
> Fetch the complete documentation index at: https://gpars.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Processing model

> How agents activate and interact with the Action Plane at runtime.

## Activation and processing flow

<Steps>
  <Step title="Manifest provided">
    The Agent provides the manifest to the Agent Runtime.
  </Step>

  <Step title="Validation">
    The Agent Runtime validates manifest structure and manifest-local capability references.
  </Step>

  <Step title="Agent loop begins">
    The agent loop begins. The agent's lifecycle is independent of MCP server availability.
  </Step>

  <Step title="MCP request issued">
    When the agent issues an MCP request, it passes through the plane boundary enforcement point.
  </Step>

  <Step title="Identity verification">
    The enforcement point verifies the agent's identity using infrastructure under the user's control (not by trusting the manifest's `id` field).
  </Step>

  <Step title="Policy evaluation">
    The enforcement point evaluates the request against the user's security policy. Operations that violate the policy are denied with `AUTHORIZATION_DENIED`.
  </Step>

  <Step title="Availability check">
    If the target MCP server is unavailable, the enforcement point returns `SERVER_UNAVAILABLE`. The agent MAY retry, wait, or adapt its approach.
  </Step>

  <Step title="Request forwarded">
    If the request is permitted and the server is available, the enforcement point forwards the request. The MCP server processes it and returns a result or an operational error (e.g., invalid parameters, resource not found).
  </Step>
</Steps>

The manifest is a declarative statement of what the agent is designed to do — not an activation gate or provisioning request. The Agent Runtime validates the manifest, while concrete MCP client wiring is provided by runtime or deployment configuration outside the manifest. Concrete MCP server binding, policy enforcement, and availability are controlled at the Action Plane boundary. MCP servers handle operational concerns; the enforcement point handles security concerns.