Joe Savona
aa1399cbcd
## What changed Accept an optional `_meta` object on `mcpServer/resource/read` and forward it to MCP `resources/read`, including reads bound to an originating tool call. Update the protocol schemas and generated TypeScript and Python types. Reject caller metadata containing host-owned `threadId`, `x-codex-turn-metadata`, or `codex/connectionLease` keys. For `codex_apps`, also reserve `connector_id`, `link_id`, and `_codex_apps.resource_uri` to preserve app and account routing. ## Testing Add integration coverage for metadata forwarding through stdio, hosted app reads with and without a thread, and origin-bound widget reads. Cover rejection of reserved keys and non-object metadata. GitOrigin-RevId: 227ee0fb5fe15fa2ff2ec66d4d5ae16de8935a8c
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.