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What Constle is not

Constle governs the environment an agent runs in. It does not decide how the agent thinks, and it is not a hosted service.

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Not an agent frameworkLink to this section

It governs the environment, not the logic. Constle doesn't decide how an agent reasons or plans. On Docker, the agent is an ordinary container image named in the Agentfile. Its HTTP client must use the proxy it's given, and it reaches MCP servers at the CONSTLE_MCP_<ID>_URL it's given.

Not a cloud providerLink to this section

constle is a single CLI that runs agents on your own machine: Linux with Docker, or Linux with KVM for Firecracker. There is no hosted service.

Not a monitoring overlayLink to this section

Enforcement sits below the agent rather than inside it. A prompt injection that tells the model to send a document to a host you didn't list does not fail because the model reconsiders: the proxy refuses the connection, and the attempt is written to the audit log as a network_blocked event. See Architecture.

Not a TLS-inspecting proxyLink to this section

Constle decides on destination names and never intercepts the agent's TLS. No certificate authority is placed inside the sandbox. The costs are stated rather than hidden:

  • There are no per-path rules for allowed hosts.
  • The caps count calls that pass through the gate to servers you price, so traffic to allowed hosts is not metered for spend.
  • Traffic to hosts you allow isn't gated. If an allowed host shares a server with an MCP server, a request can reach that MCP server past the gate (limitation 2).
  • The API keys you declare under credentials are passed into the sandbox, where the agent can read them.

Not a filesystem policy engineLink to this section

The agent's file access comes from its image. capabilities is not a permission system, and there is no gate on file writes, because writes have no chokepoint outside the sandbox.

Not a fleet platformLink to this section

One CLI, on your own machine. It runs agents there, and their audit logs and spend ledgers stay in your home directory, under ~/.constle/.

Not finishedLink to this section

Constle is early. The Known limitations are listed up front rather than discovered later, and fields in the Agentfile's specification are labelled Enforced, Validated, Declared or Informational (The Agentfile).