Charlie Marsh
cc44ffb3e2
## Why MCP tool hooks need to invoke model-hidden tools even when a subagent's cached server has not started. Their timeout must also cover server startup. ## What changed - Let cached servers with allowed model-hidden tools remain dormant until called. - Wait for the selected server when executing an MCP hook, leaving unrelated cached servers dormant, and apply the hook timeout to the entire operation. - Capture tool namespace attribution after startup and retain it only while catalog revisions remain unchanged. - Validate the server, environment, and tool filter before starting a server or capturing attribution. ## Testing Extend integration coverage for cached subagent hooks under both startup readiness modes, startup timeouts without context injection, and namespace attribution for hook and token-budget context while keeping tools hidden from the model. Verify that a direct call starts a cached server whose tools are hidden from model exposure. GitOrigin-RevId: 7a54b69aa2515722aeb925e03e1667bf63aa67ca
Codex MCP runtime
This crate manages Codex's MCP connections, tool calls, and their captured authority.
Sandbox request metadata
An MCP server advertises the experimental codex/sandbox-state capability to
receive sandbox metadata on tool calls. The deprecated capability name
codex/sandbox-state-meta opts into the same contract during migration.
Codex supplies these entries in the request's _meta object:
| Key | Value |
|---|---|
codex/sandbox-state |
Opaque policy to pass to codex sandbox --sandbox-state-json. |
codex/sandbox-state-meta |
An identical copy of that policy under the deprecated name. |
codex/sandbox-launcher |
When available, an object with an absolute codexExecutable path to a verified full Codex CLI on the MCP server's host. |
Use the launcher path to invoke sandbox --sandbox-state-json with the entire
state value serialized as one argument, followed by -- and the command to run.
The state contains neither launcher discovery data nor deprecation messages.
Preserve unknown policy fields by forwarding the original value rather than
deserializing and reconstructing it. The two state names are aliases, not separate
policies; new consumers should prefer codex/sandbox-state.
Launcher metadata is currently available only for local stdio servers. An HTTP endpoint, including loopback, or a remote executor does not establish a shared filesystem with the harness. Codex omits the launcher when its path is unknown, not representable as UTF-8, or fails the cached capability probe. Absence does not authorize a PATH search or unsandboxed fallback. Servers that require a launcher must fail closed or require an explicit operator opt-out.
The state and launcher describe the issuing call. Retain both when starting a
long-lived subprocess or caching policy-bound results; reject changed authority
before reusing them. Tool arguments supplied by the model are not authority.
See sandbox_metadata.rs for the wire types and
binding.rs for execution-environment selection.