## Summary
This changes `js_repl` so saved references to `codex.tool(...)` and
`codex.emitImage(...)` keep working across cells.
Previously, those helpers were recreated per exec and captured that
exec's `message.id`. If a persisted object or saved closure reused an
old helper in a later cell, the nested tool/image call could fail with
`js_repl exec context not found`.
This patch:
- keeps stable `codex.tool` and `codex.emitImage` helper identities in
the kernel
- resolves the current exec dynamically at call time using
`AsyncLocalStorage`
- adds regression coverage for persisted helper references across cells
- updates the js_repl docs and project-doc instructions to describe the
new behavior and its limits
## Why
We already support persistent top-level bindings across `js_repl` cells,
so persisted objects should be able to reuse `codex` helpers in later
active cells. The bug was that helper identity was exec-scoped, not
kernel-scoped.
Using `AsyncLocalStorage` fixes the cross-cell reuse case without
falling back to a single global active exec that could accidentally
attribute stale background callbacks to the wrong cell.
## Summary
This PR narrows original image detail handling to a single opt-in
feature:
- `image_detail_original` lets the model request `detail: "original"` on
supported models
- Omitting `detail` preserves the default resized behavior
The model only sees `detail: "original"` guidance when the active model
supports it:
- JS REPL instructions include the guidance and examples only on
supported models
- `view_image` only exposes a `detail` parameter when the feature and
model can use it
The image detail API is intentionally narrow and consistent across both
paths:
- `view_image.detail` supports only `"original"`; otherwise omit the
field
- `codex.emitImage(..., detail)` supports only `"original"`; otherwise
omit the field
- Unsupported explicit values fail clearly at the API boundary instead
of being silently reinterpreted
- Unsupported explicit `detail: "original"` requests fall back to normal
behavior when the feature is disabled or the model does not support
original detail
## Summary
This PR adds two read-only path helpers to `js_repl`:
- `codex.cwd`
- `codex.homeDir`
They are exposed alongside the existing `codex.tmpDir` helper so the
REPL can reference basic host path context without reopening direct
`process` access.
## Implementation
- expose `codex.cwd` and `codex.homeDir` from the js_repl kernel
- make `codex.homeDir` come from the kernel process environment
- pass session dependency env through js_repl kernel startup so
`codex.homeDir` matches the env a shell-launched process would see
- keep existing shell `HOME` population behavior unchanged
- update js_repl prompt/docs and add runtime/integration coverage for
the new helpers
## Summary
This updates the `js_repl` prompt and docs to make the image guidance
less confusing.
## What changed
- Clarified that `codex.emitImage(...)` adds one image per call and can
be called multiple times to emit multiple images.
- Reworded the image-encoding guidance to be general `js_repl` advice
instead of `ImageDetailOriginal`-specific behavior.
- Updated the guidance to recommend JPEG at about quality 85 when lossy
compression is acceptable, and PNG when transparency or lossless detail
matters.
- Mirrored the same wording in the public `js_repl` docs.
### Motivation
- Prevent untrusted js_repl code from supplying arbitrary external URLs
that the host would forward into model input and cause external fetches
/ data exfiltration. This change narrows the emitImage contract to safe,
self-contained data URLs.
### Description
- Kernel: added `normalizeEmitImageUrl` and enforce that string-valued
`codex.emitImage(...)` inputs and `input_image`/content-item paths only
accept non-empty `data:` URLs; byte-based paths still produce data URLs
as before (`kernel.js`).
- Host: added `validate_emitted_image_url` and check `EmitImage`
requests before creating `FunctionCallOutputContentItem::InputImage`,
returning an error to the kernel if the URL is not a `data:` URL
(`mod.rs`).
- Tests/docs: added a runtime test
`js_repl_emit_image_rejects_non_data_url` to assert rejection of
non-data URLs and updated user-facing docs/instruction text to state
`data URL` support instead of generic direct image URLs (`mod.rs`,
`docs/js_repl.md`, `project_doc.rs`).
### Testing
- Ran `just fmt` in `codex-rs`; it completed successfully.
- Added a runtime test (`cargo test -p codex-core
js_repl_emit_image_rejects_non_data_url`) but executing the test in this
environment failed due to a missing system dependency required by
`codex-linux-sandbox` (the vendored `bubblewrap` build requires
`libcap.pc` via `pkg-config`), so the test could not be run here.
- Attempted a focused `cargo test` invocation with and without default
features; both compile/test attempts were blocked by the same missing
system `libcap` dependency in this environment.
------
[Codex
Task](https://chatgpt.com/codex/tasks/task_i_69a7837bce98832d91db92d5f76d6cbe)
## Summary
- Change `js_repl` failed-cell persistence so later cells keep prior
bindings plus only the current-cell bindings whose initialization
definitely completed before the throw.
- Preserve initialized lexical bindings across failed cells via
module-namespace readability, including top-level destructuring that
partially succeeds before a later throw.
- Preserve hoisted `var` and `function` bindings only when execution
clearly reached their declaration site, and preserve direct top-level
pre-declaration `var` writes and updates through explicit write-site
markers.
- Preserve top-level `for...in` / `for...of` `var` bindings when the
loop body executes at least once, using a first-iteration guard to avoid
per-iteration bookkeeping overhead.
- Keep prior module state intact across link-time failures and
evaluation failures before the prelude runs, while still allowing failed
cells that already recreated prior bindings to persist updates to those
existing bindings.
- Hide internal commit hooks from user `js_repl` code after the prelude
aliases them, so snippets cannot spoof committed bindings by calling the
raw `import.meta` hooks directly.
- Add focused regression coverage for the supported failed-cell
behaviors and the intentionally unsupported boundaries.
- Update `js_repl` docs and generated instructions to describe the new,
narrower failed-cell persistence model.
## Motivation
We saw `js_repl` drop bindings that had already been initialized
successfully when a later statement in the same cell threw, for example:
const { context: liveContext, session } =
await initializeGoogleSheetsLiveForTab(tab);
// later statement throws
That was surprising in practice because successful earlier work
disappeared from the next cell.
This change makes failed-cell persistence more useful without trying to
model every possible partially executed JavaScript edge case. The
resulting behavior is narrower and easier to reason about:
- prior bindings are always preserved
- lexical bindings persist when their initialization completed before
the throw
- hoisted `var` / `function` bindings persist only when execution
clearly reached their declaration or a supported top-level `var` write
site
- failed cells that already recreated prior bindings can persist writes
to those existing bindings even if they introduce no new bindings
The detailed edge-case matrix stays in `docs/js_repl.md`. The
model-facing `project_doc` guidance is intentionally shorter and focused
on generation-relevant behavior.
## Supported Failed-Cell Behavior
- Prior bindings remain available after a failed cell.
- Initialized lexical bindings remain available after a failed cell.
- Top-level destructuring like `const { a, b } = ...` preserves names
whose initialization completed before a later throw.
- Hoisted `function` bindings persist when execution reached the
declaration statement before the throw.
- Direct top-level pre-declaration `var` writes and updates persist, for
example:
- `x = 1`
- `x += 1`
- `x++`
- short-circuiting logical assignments only persist when the write
branch actually runs
- Non-empty top-level `for...in` / `for...of` `var` loops persist their
loop bindings.
- Failed cells can persist updates to existing carried bindings after
the prelude has run, even when the cell commits no new bindings.
- Link failures and eval failures before the prelude do not poison
`@prev`.
## Intentionally Unsupported Failed-Cell Cases
- Hoisted function reads before the declaration, such as `foo(); ...;
function foo() {}`
- Aliasing or inference-based recovery from reads before declaration
- Nested writes inside already-instrumented assignment RHS expressions
- Destructuring-assignment recovery for hoisted `var`
- Partial `var` destructuring recovery
- Pre-declaration `undefined` reads for hoisted `var`
- Empty top-level `for...in` / `for...of` loop vars
- Nested or scope-sensitive pre-declaration `var` writes outside direct
top-level expression statements
## Summary
- add `js_repl` support for dynamic imports of relative and absolute
local ESM `.js` / `.mjs` files
- keep bare package imports on the native Node path and resolved from
REPL-global search roots (`CODEX_JS_REPL_NODE_MODULE_DIRS`, then `cwd`),
even when they originate from imported local files
- restrict static imports inside imported local files to other local
relative/absolute `.js` / `.mjs` files, and surface a clear error for
unsupported top-level static imports in the REPL cell
- run imported local files inside the REPL VM context so they can access
`codex.tmpDir`, `codex.tool`, captured `console`, and Node-like
`import.meta` helpers
- reload local files between execs so later `await import("./file.js")`
calls pick up edits and fixed failures, while preserving package/builtin
caching and persistent top-level REPL bindings
- make `import.meta.resolve()` self-consistent by allowing the returned
`file://...` URLs to round-trip through `await import(...)`
- update both public and injected `js_repl` docs to clarify the narrowed
contract, including global bare-import resolution behavior for local
absolute files
## Testing
- `cargo test -p codex-core js_repl_`
- built codex binary and verified behavior
---------
Co-authored-by: Codex <noreply@openai.com>
## Summary
Instead of always adding inner function call outputs to the model
context, let js code decide which ones to return.
- Stop auto-hoisting nested tool outputs from `codex.tool(...)` into the
outer `js_repl` function output.
- Keep `codex.tool(...)` return values unchanged as structured JS
objects.
- Add `codex.emitImage(...)` as the explicit path for attaching an image
to the outer `js_repl` function output.
- Support emitting from a direct image URL, a single `input_image` item,
an explicit `{ bytes, mimeType }` object, or a raw tool response object
containing exactly one image.
- Preserve existing `view_image` original-resolution behavior when JS
emits the raw `view_image` tool result.
- Suppress the special `ViewImageToolCall` event for `js_repl`-sourced
`view_image` calls so nested inspection stays side-effect free until JS
explicitly emits.
- Update the `js_repl` docs and generated project instructions with both
recommended patterns:
- `await codex.emitImage(codex.tool("view_image", { path }))`
- `await codex.emitImage({ bytes: await page.screenshot({ type: "jpeg",
quality: 85 }), mimeType: "image/jpeg" })`
#### [git stack](https://github.com/magus/git-stack-cli)
- ✅ `1` https://github.com/openai/codex/pull/13050
- 👉 `2` https://github.com/openai/codex/pull/13331
- ⏳ `3` https://github.com/openai/codex/pull/13049
## Summary
- add tracing-based diagnostics for nested `codex.tool(...)` calls made
from `js_repl`
- emit a bounded, sanitized summary at `info!`
- emit the exact raw serialized response object or error string seen by
JavaScript at `trace!`
- document how to enable these logs and where to find them, especially
for `codex app-server`
## Why
Nested `codex.tool(...)` calls inside `js_repl` are a debugging
boundary: JavaScript sees the tool result, but that result is otherwise
hard to inspect from outside the kernel.
This change adds explicit tracing for that path using the repo’s normal
observability pattern:
- `info` for compact summaries
- `trace` for exact raw payloads when deep debugging is needed
## What changed
- `js_repl` now summarizes nested tool-call results across the response
shapes it can receive:
- message content
- function-call outputs
- custom tool outputs
- MCP tool results and MCP error results
- direct error strings
- each nested `codex.tool(...)` completion logs:
- `exec_id`
- `tool_call_id`
- `tool_name`
- `ok`
- a bounded summary struct describing the payload shape
- at `trace`, the same path also logs the exact serialized response
object or error string that JavaScript received
- docs now include concrete logging examples for `codex app-server`
- unit coverage was added for multimodal function output summaries and
error summaries
## How to use it
### Summary-only logging
Set:
```sh
RUST_LOG=codex_core::tools::js_repl=info
```
For `codex app-server`, tracing output is written to the server process
`stderr`.
Example:
```sh
RUST_LOG=codex_core::tools::js_repl=info \
LOG_FORMAT=json \
codex app-server \
2> /tmp/codex-app-server.log
```
This emits bounded summary lines for nested `codex.tool(...)` calls.
### Full raw debugging
Set:
```sh
RUST_LOG=codex_core::tools::js_repl=trace
```
Example:
```sh
RUST_LOG=codex_core::tools::js_repl=trace \
LOG_FORMAT=json \
codex app-server \
2> /tmp/codex-app-server.log
```
At `trace`, you get:
- the same `info` summary line
- a `trace` line with the exact serialized response object seen by
JavaScript
- or the exact error string if the nested tool call failed
### Where the logs go
For `codex app-server`, these logs go to process `stderr`, so redirect
or capture `stderr` to inspect them.
Example:
```sh
RUST_LOG=codex_core::tools::js_repl=trace \
LOG_FORMAT=json \
/Users/fjord/code/codex/codex-rs/target/debug/codex app-server \
2> /tmp/codex-app-server.log
```
Then inspect:
```sh
rg "js_repl nested tool call" /tmp/codex-app-server.log
```
Without an explicit `RUST_LOG` override, these `js_repl` nested
tool-call logs are typically not visible.
# External (non-OpenAI) Pull Request Requirements
In `js_repl` mode, module resolution currently starts from
`js_repl_kernel.js`, which is written to a per-kernel temp dir. This
effectively means that bare imports will not resolve.
This PR adds a new config option, `js_repl_node_module_dirs`, which is a
list of dirs that are used (in order) to resolve a bare import. If none
of those work, the current working directory of the thread is used.
For example:
```toml
js_repl_node_module_dirs = [
"/path/to/node_modules/",
"/other/path/to/node_modules/",
]
```
## Summary
This PR adds host-integrated helper APIs for `js_repl` and updates model
guidance so the agent can use them reliably.
### What’s included
- Add `codex.tool(name, args?)` in the JS kernel so `js_repl` can call
normal Codex tools.
- Keep persistent JS state and scratch-path helpers available:
- `codex.state`
- `codex.tmpDir`
- Wire `js_repl` tool calls through the standard tool router path.
- Add/align `js_repl` execution completion/end event behavior with
existing tool logging patterns.
- Update dynamic prompt injection (`project_doc`) to document:
- how to call `codex.tool(...)`
- raw output behavior
- image flow via `view_image` (`codex.tmpDir` +
`codex.tool("view_image", ...)`)
- stdio safety guidance (`console.log` / `codex.tool`, avoid direct
`process.std*`)
## Why
- Standardize JS-side tool usage on `codex.tool(...)`
- Make `js_repl` behavior more consistent with existing tool execution
and event/logging patterns.
- Give the model enough runtime guidance to use `js_repl` safely and
effectively.
## Testing
- Added/updated unit and runtime tests for:
- `codex.tool` calls from `js_repl` (including shell/MCP paths)
- image handoff flow via `view_image`
- prompt-injection text for `js_repl` guidance
- execution/end event behavior and related regression coverage
#### [git stack](https://github.com/magus/git-stack-cli)
- ✅ `1` https://github.com/openai/codex/pull/10674
- 👉 `2` https://github.com/openai/codex/pull/10672
- ⏳ `3` https://github.com/openai/codex/pull/10671
- ⏳ `4` https://github.com/openai/codex/pull/10673
- ⏳ `5` https://github.com/openai/codex/pull/10670
Curtis 'Fjord' Hawthorne ·
aaronl-openai ·