## Why
`PathUri::from_abs_path` can fail for absolute paths that do not have a
normal `file:` URI representation, forcing filesystem call sites to
handle a conversion error even though the original path can be preserved
losslessly.
## What
Make `from_abs_path` infallible and migrate its callers. Unrepresentable
paths use `file:///%00/bad/path/<base64>`, encoding Unix bytes or
Windows UTF-16LE; `to_abs_path` validates and decodes that fallback. The
leading encoded null reserves a namespace that cannot collide with a
real Unix or Windows path, and fallback URIs remain opaque to lexical
path operations.
## Validation
Added path-URI coverage for Unix null and non-UTF-8 paths, Windows
device/verbatim and non-Unicode paths, serialization, malformed
fallbacks, opaque lexical operations, invalid native payloads, and
literal `/bad/path` collision resistance.
## Why
CCA can select a capability root that lives in an executor environment,
but
Codex only had a host-filesystem plugin loader. Before selected executor
plugins can contribute MCP servers, we need a small package boundary
that can
answer:
> Does this selected root contain a plugin, and if so, what does its
manifest
> declare?
The answer must come from the selected environment's filesystem. A
failed
executor lookup must never fall back to the orchestrator filesystem.
## What this changes
This PR introduces:
```rust
PluginProvider::resolve(root)
-> Result<Option<ResolvedPlugin>, Error>
```
`ExecutorPluginProvider` resolves one `SelectedCapabilityRoot` through
its
exact `environment_id`. It checks the recognized manifest locations,
reads the
manifest through that environment's `ExecutorFileSystem`, and returns an
inert
`ResolvedPlugin` containing:
- the opaque selected-root ID;
- the environment-bound plugin root;
- the authority-bound manifest resource;
- parsed metadata and authority-bound component locators.
Descriptor construction rejects manifest or component paths outside the
selected package root, so consumers cannot accidentally lose the package
boundary when they receive a resolved plugin.
If the root has no plugin manifest, resolution returns `None`, allowing
the
caller to treat it as a standalone capability such as a skill.
```text
selected root: repo -> env-1:/workspace/repo
|
| env-1 filesystem only
v
.codex-plugin/plugin.json
|
v
ResolvedPlugin { authority, root, manifest }
```
The existing host loader and the new executor provider now share the
same
manifest parser. Existing `codex-core-plugins::manifest` type paths
remain
available through re-exports, so host behavior and callers are
unchanged.
## Scope
This is intentionally a non-user-visible package-resolution PR. It does
not:
- parse or register plugin MCP server configurations;
- activate skills, connectors, hooks, or MCP servers;
- change app-server wiring;
- introduce host fallback, caching, or lifecycle behavior.
#27670 has merged, and this PR is now based directly on `main`. Together
with
the resolved MCP catalog from #27634, it establishes the inputs needed
for the
executor stdio MCP vertical without changing the existing MCP runtime.
## Follow-up
The next PR will consume `ResolvedPlugin`, read its declared/default MCP
config
through the same executor filesystem, bind supported stdio servers to
that
environment, and feed those registrations into the resolved MCP catalog.
An
app-server E2E will prove that selecting an executor plugin exposes and
invokes
its tool on the owning executor.
Resume/fork semantics, dynamic environment replacement, and non-stdio
placement remain separate lifecycle decisions.
## Validation
- `just fmt`
- `cargo check --tests -p codex-plugin -p codex-core-plugins`
- `just bazel-lock-check`
- `git diff --check`
Test targets were compiled but not executed locally; CI will run the
test and
Clippy suites.
## Why
We're moving exec-server to use PathUri for its internal path
representations.
## What
Move `ExecutorFileSystem` APIs to use `PathUri` instead of
`AbsolutePathBuf`. Future changes will convert higher-level parts of
exec-server.
Load plugin manifests through a shared discoverable-path helper so
manifest reads, installs, and skill names all see the same alternate
manifest location.
Adam Perry @ OpenAIandGitHub
jifandGitHub
xl-openaiandGitHub
pakrym-oaiandGitHub
