## Why
An `apply_patch` path can be replaced with a symlink after verification, allowing an unsandboxed patch operation to reach a different file than the one that was approved.
## What changed
- Add `follow_symlinks` options to executor filesystem reads, writes, metadata lookups, directory creation, and removal, including the corresponding `followSymlinks` protocol fields.
- Implement no-follow filesystem operations on Unix and Windows that reject links in any path component and restrict file access to regular files.
- Run `apply_patch` with symlink traversal disabled when an otherwise-required sandbox is bypassed, while retaining the existing follow-symlink default for standalone callers.
## Testing
- Cover leaf and ancestor symlinks across patch add, update, delete, and move operations, including a path swap after verification.
- Exercise local and remote no-follow filesystem behavior, concurrent directory creation, special-file rejection, and Windows reparse points.
GitOrigin-RevId: 43fd479084891493ce13564fbd894b98f329c6dd
## Why
Filesystem permission paths can use a convention that differs from the host
running Codex. Converting them immediately to native absolute paths can change
the meaning of ambiguous paths such as `/C:/secret` or Windows UNC paths.
## What changed
- Store literal filesystem permission paths as `PathUri` values through the
runtime policy and execution protocol.
- Keep legacy string-based serialization at explicit protocol boundaries and
reject conversions that cannot be represented losslessly.
- Encode native paths as opaque URIs when a normal file URI would imply the
wrong path convention.
## Testing
Added coverage for cross-platform and ambiguous path round trips, UNC path
variants, permission-profile serialization, and deny-policy enforcement.
GitOrigin-RevId: 5247713796d1f2bb4e02f94eb9fc82d4698060f0
## Why
Streaming reads previously rejected requests that used a platform filesystem
sandbox.
## What changed
- Open streamed files in the sandbox helper and return the open file to the
exec-server by passing a file descriptor on Unix or duplicating a file handle
on Windows.
- Advertise support through the `sandboxedFileStreaming` environment capability.
- Preserve close-on-exec behavior for transferred descriptors, including the
required inherited-descriptor cleanup on macOS.
## Testing
- Cover bounded sandboxed streams, continued reads after path replacement, and
rejection of symlink escapes outside readable roots.
GitOrigin-RevId: 677b2444b74e834b78b87a8554bc119c1c6e08b2
## Why
Remote environment connections need to honor Codex's effective outbound proxy policy, including when a rendezvous connection reconnects.
## What changed
- Pass the configured `HttpClientFactory` into remote environment transports and use `WebSocketConnector` for exec-server and rendezvous WebSockets.
- Resolve proxy routes asynchronously so these connections can use the configured system proxy.
- Add connector options that preserve Tungstenite's default TLS behavior and enable `TCP_NODELAY` for latency-sensitive rendezvous traffic.
## Testing
- Verify prepared remote environments connect through a configured system proxy.
- Verify initial and reconnected encrypted relay peers use the system proxy.
- Cover default TLS selection and opt-in `TCP_NODELAY` behavior in the WebSocket client.
GitOrigin-RevId: 8a8da2116e37cb3a891269d0c0b037986fecdd3c
## Why
Default read-only protections for project metadata should apply when paths such
as `.git`, `.agents`, and `.codex` exist, without causing sandbox setup to
materialize missing paths as ACL targets.
## What changed
- Add an optional `missing_path_behavior` to filesystem sandbox entries and
mark default project-metadata protections with `skip`.
- Preserve the behavior through permission transforms and exec/MCP protocol
serialization while keeping existing path wire variants stable.
- Ignore skip-missing entries when projecting configuration or Windows sandbox
overrides, while retaining explicit metadata carveouts.
## Testing
- Cover protocol round trips for path and special-path entries.
- Verify default metadata protections and Windows explicit carveout handling.
GitOrigin-RevId: 6df13dadacdd131c44aab9f15a967c81051355c1
## Why
Downstream refactors are producing confusing code with this
functionality having a very generic name. Encoding the specific
conversion approach in the method name makes it clearer.
## What
Rename `PathUri::from_path` to `PathUri::from_host_native_path` and
update its Rust call sites.
## Why
`fs/readFile` buffers the entire file in one response, which makes large
remote reads expensive and prevents callers from applying backpressure.
We need an opt-in streaming path with bounded block sizes while
preserving the existing single-call API for small and sandboxed reads.
## What changed
- Add `ExecServerClient::stream`, returning a named `FileReadStream`
that implements `futures::Stream` and yields immutable 1 MiB byte
blocks.
- Add internal `fs/open`, `fs/readBlock`, and `fs/close` RPCs.
`fs/readBlock` accepts an explicit offset and length.
- Keep unsandboxed files open between block reads, cap open handles per
connection, and clean them up on EOF, error, stream drop, explicit
close, or connection shutdown.
- Reject platform-sandboxed streaming opens instead of turning the
one-shot sandbox helper into a persistent server. Existing `fs/readFile`
behavior is unchanged.
## Testing
- `just test -p codex-exec-server`
- Integration coverage for 1 MiB chunking, exact block-boundary EOF,
sandbox rejection, and continued reads from the opened file after path
replacement.
- Handle-manager coverage for non-sequential offsets, variable block
lengths, the 128-handle limit, and capacity release after close.
