## Why
Responses Lite rebuilds its tools and base-instruction prefix for each request. Stable item identities let follow-up WebSocket requests recognize that unchanged prefix and send only incremental input.
## What changed
- Derive deterministic IDs for additional-tools and base-instruction items from the thread ID and each item's serialized payload.
- Preserve IDs when rebuilding an unchanged request or resuming a session, while changing them when the thread or payload changes.
## Testing
- Cover ID stability and payload/thread sensitivity in request construction.
- Verify resumed Responses Lite sessions reuse prefix IDs and WebSocket follow-ups use `previous_response_id` with only new input items.
GitOrigin-RevId: 3c8548b96979d7578865b0ccc51c147926823478
## What changed
- Build Responses Lite base instructions through a dedicated context fragment so the developer message carries the `model.base_instructions` content kind.
- Apply provider metadata cleanup after adding the base-instructions message, preserving the existing behavior for non-OpenAI providers.
## Testing
- Extend Responses Lite request coverage to verify the annotation is present for OpenAI requests and omitted for a third-party provider.
GitOrigin-RevId: b0317f92dfb9570860688b49e3a7668da516ee8c
## Why
Image preparation can rewrite message content, including replacing images that
cannot be processed with model-visible error text. The positional content-kind
metadata must stay aligned with those rewrites.
## What changed
- Process message images together with their content-kind annotations.
- Preserve existing kinds for unchanged and resized content.
- Classify failed-image placeholders as `images.preparation_error`.
## Testing
- Cover metadata preservation across successful, resized, and failed images.
- Verify Responses Lite sends `user.image` and `images.preparation_error` kinds.
GitOrigin-RevId: 1be7bcbe47014251019bfff0d826c9dfe3239dec
## Why
App-server logs can be persisted or included in submitted diagnostics, so credentials used by model providers, authentication refreshes, and attestation requests must not appear in diagnostic output.
## What changed
- Add `RedactedString`, which preserves serialization and string access while replacing debug output with `<redacted>`.
- Use it for model-provider bearer tokens, header and query values, authentication command arguments, and attestation tokens.
- Avoid logging JSON-RPC error payloads and parser or authentication errors that may echo credentials; retain safe context such as error codes and categories.
## Testing
- Add an app-server regression test that exercises provider credentials, refreshed authentication tokens, and attestation tokens, then verifies none appear in persisted SQLite or submitted diagnostic logs.
GitOrigin-RevId: 8c50408adf94d93847658b1320682cf3b637d2cc
## What changed
- Set `parallel_tool_calls` for regular and remote compaction prompts without consulting model metadata.
- Remove `supports_parallel_tool_calls` from `ModelInfo`, the bundled model catalog, and related fixtures.
- Preserve the existing Responses Lite behavior that disables parallel tool calls at request construction.
GitOrigin-RevId: 49552bdf97e71fa57325abb49f8adc0c88f1401a
## What changed
- Add `TurnInputRequest` and typed submission results for atomically starting a turn, steering the active turn, or declining input with a specific reason.
- Expose `start_or_steer_turn`, `start_turn_if_idle`, and `steer_turn` on `CodexThread`, and migrate Core consumers to these APIs.
- Make app-server `turn/start` steer an active regular turn and return that turn's ID. Reject incompatible output schemas and non-steerable turns without applying settings or enqueueing input.
## Testing
- Cover concurrent start-or-steer submissions, accepted and rejected settings updates, output-schema compatibility, idle-start rejection, and app-server steering.
GitOrigin-RevId: dd9b5528d76ec650c019e97af420bc13190ea86a
## What changed
- Stop adding `code_mode_tool_names` to Responses Lite turn metadata.
- Keep `code_mode_tool_names` reserved so client metadata cannot reintroduce the removed, unbounded inventory.
- Use the opt-in `tool_namespaces_info` metadata, including each function's `code_mode_name`, when authoritative tool details are requested.
## Testing
- Update Responses Lite and code-mode tests to verify the opt-in namespace metadata and normalized code-mode names.
GitOrigin-RevId: cbfb9af984de71c7cc175d0cd47ae799a5275309
## What changed
- Add opt-in `tool_namespaces_info` metadata for Responses Lite turns when
`tool_registry.turn_metadata_includes_tool_info` is enabled.
- Describe each model-visible function's namespace, direct and deferred
exposure, Code Mode name, and harness or MCP ownership.
- Reject visible namespaces shared by different owners when strict collision
checking and tool inventory metadata are enabled.
- Keep tool inventories out of compatibility headers and metadata sent to MCP
servers.
## Testing
- Cover opt-in behavior, MCP exposure details, namespace ownership collisions,
reserved metadata handling, and Responses Lite request serialization.
GitOrigin-RevId: 6a6965d2ba98e29444fdfbb4ccec6aafcf0391e6
## What changed
- Group top-level function and custom tool definitions into a single `functions` namespace for Responses Lite providers that support namespaced tools.
- Normalize missing, empty, and explicit `functions` namespaces to the same tool identity across registration, routing, lifecycle hooks, configuration, and tool search.
- Keep default tool names unprefixed in code mode, display output, and dispatch traces while preserving explicit non-default namespaces.
## Testing
- Add coverage for Responses Lite serialization, tool search results, namespace normalization and collision handling, routing, lifecycle events, and code-mode namespace policies.
GitOrigin-RevId: d48414005b5d22d39b11a198e19c47814d3a19f2
## Why
Amazon Bedrock supports hosted text web search, but it rejects the
`search_content_types` field used for multimodal search and does not support
external live or indexed web access.
## What changed
- Advertise hosted web search for Amazon Bedrock while marking external web
access as unsupported.
- Resolve unsupported live and indexed modes to cached search, or disable the
tool when cached search is prohibited by managed requirements.
- Normalize built-in and configured Bedrock model catalogs to text-only web
search, and retain the runtime provider in session configuration so turn
setup can apply its capabilities.
## Testing
- Cover cached fallback, managed-mode restrictions, text-only tool payloads,
provider capabilities, and catalog normalization.
GitOrigin-RevId: 310473849257401654388a4ebb42920e03aa3228
## What changed
- Add `code_mode_tool_names` to Responses Lite turn metadata, mapping each normalized code-mode identifier to its structured `ToolName`.
- Reserve the metadata key against client overrides and omit it from metadata exposed to external MCP servers.
- Keep non-Lite requests and the legacy top-level client metadata unchanged.
## Testing
- Cover HTTP and WebSocket Responses Lite requests, including switching from a non-Lite model.
- Verify reserved-key handling and external MCP metadata filtering.
GitOrigin-RevId: b678afba13d57a91e26f5895aa37238fbb4cb276
## What changed
- Add the `supports_standalone_web_search` model-provider setting, defaulting to `false`, and preserve it in remote thread configuration.
- Enable the standalone `web.run` tool for opted-in custom Responses providers when web search is enabled and the runtime provider supports it.
- Send standalone search requests through the custom provider's endpoint and authentication.
## Testing
- Cover opt-in, default-off, disabled-search, and unsupported-provider behavior.
- Verify custom-provider search request routing and authorization through the app server.
GitOrigin-RevId: 7c5f96b0ce924ad2b9715c45bfc635e89fc39cff
## Summary
- allow the standalone image-generation and web-search extensions for
the actor-authorized provider shape used by CCA
- preserve builtin `image_generation` and `web_search` for older models
and existing flows
- keep ordinary non-OpenAI providers excluded from both extensions
- remove only the image extension local managed-AuthManager requirement
that CCA cannot satisfy
- share actor-authorization detection through `ModelProviderInfo`
- keep Core tests focused on routing behavior and cover header-shape
edge cases in `model-provider-info`
- add a Responses Lite regression that verifies both
`image_gen.imagegen` and `web.run`
## Why
CCA uses a provider named `local` with `requires_openai_auth: false` and
a non-empty `x-openai-actor-authorization` header. Core accepts that
provider shape, but both extension provider-name gates rejected it;
image generation additionally required a Codex-managed login.
The standalone paths must coexist with existing builtin tools. New
Responses Lite models can receive `image_gen.imagegen` and `web.run`,
while older models continue using builtin tools.
## Impact
This enables both standalone extensions for CCA once installed
downstream, without removing or changing builtin-tool compatibility for
older models.
## Validation
- `just test -p codex-core
responses_lite_exposes_standalone_tools_for_actor_authorized_provider`
- `just test -p codex-core
responses_lite_uses_standalone_web_search_and_image_generation`
- `just test -p codex-core
hosted_tools_follow_provider_auth_model_and_config_gates`
- `just test -p codex-image-generation-extension`
- `just test -p codex-web-search-extension`
- `just test -p codex-model-provider-info`
- `just fmt`
- `git diff --check`
## Why
Some extension hosts need generated images returned without writing them
to the local filesystem or giving the model a local path.
## What changed
**tl;dr**: we now conduct all extension operations in the image gen
extension
- Let hosts provide an optional image save root when installing the
extension.
- Save images and return path hints only when a save root is configured.
- Return image data without saving or adding a path hint when no save
root is configured.
- Preserve the extension-provided `saved_path` instead of persisting
extension images again in core.
- Leave built-in image generation unchanged.
## Validation
- `just test -p codex-image-generation-extension`
- `just test -p codex-app-server
standalone_image_generation_returns_saved_path_hint_to_model`
- `just test -p codex-core
extension_tool_uses_granted_turn_permissions_without_local_persistence`
- `just test -p codex-core tools::handlers::extension_tools::tests`
- tested on CODEX CLI on both save_root: CODEX_HOME and None
- tested on CODEX APP on both as well
When using Responses Lite, we should all use `additional_tools` and a
developer item instead of the top level tools array & instructions
field. This keeps things 1-to-1.
Forced namespacing for _all_ tools will land in a following PR after
some coordination & fixes in Responses API (around collisions & return
items).
The goal is to eventually expand the scope of this to _all_ requests
from codex, but that will require larger coordination across providers &
slower rollout.
## What
This PR will extend the existing centralized image-preparation path to
replace HTTP(S) image inputs with a model visible error message. It
won't "ruin" and break existing rollouts, but it will deprecate support
for the pathway. App server clients should no longer use HTTP image urls
if they'd like to upgrade.
The HTTP image url pathway is currently resolved in the responsesapi. It
is slow and not reccomended.
## Behavior
- HTTP(S) image URL: replace with `input_text`
- data URL: use the existing decode and resize path
- other image URL schemes: leave unchanged
This intentionally does not change app-server ingress. That validation
remains a follow-up.
## Test plan
- `just test -p codex-core -E
'test(/image_preparation|prepares_image_failures_before_history_insertion|prepares_resumed_history_before_installing_it|responses_lite_prepares_images/)'`
— 7 passed
- `just fix -p codex-core`
- `just fmt`
## What
- make Fjord's centralized response-item image preparation unconditional
for new and resumed history
- have local user images and `view_image` outputs always defer decoding
and resizing to that path
- retain `resize_all_images` as an ignored, removed compatibility key
for released clients
- delete the flag-off producer paths and obsolete policy-specific tests
## Why
Centralized preparation is now the intended image path. Keeping the
runtime feature checks also kept two image-processing implementations
alive and allowed client config to select the legacy behavior.
This is a clean replacement for #28975, rebuilt from the latest `main`.
## How
`prepare_response_items` now runs whenever items enter history and
whenever persisted history is reconstructed. Producers emit deferred
image data, so malformed images become the existing model-visible
placeholder instead of failing the session at the producer.
## Test plan
- `just fmt`
- `just fix -p codex-core -p codex-features`
- `just test -p codex-features` — 52 passed
- focused affected `codex-core` set — 20 passed
- `just test -p codex-core handle_accepts_explicit_high_detail` — 1
passed
- full `just test -p codex-core` attempt — 2,723 passed; 88 unrelated
environment failures from read-only `~/.codex` SQLite state and
unavailable integration helper binaries
## Why
Remote compaction v2 is ready to become the default for providers that
already support remote compaction. Leaving it behind an
under-development opt-in keeps eligible sessions on the legacy
remote-compaction path.
This does not broaden provider eligibility: OpenAI and Azure move to v2,
while Bedrock and OSS providers retain their existing local-compaction
behavior.
## What changed
- Mark `remote_compaction_v2` stable and enable it by default.
- Make tests that intentionally cover legacy remote compaction
explicitly disable v2.
- Update parity coverage so v2 exercises the production default and only
legacy mode opts out.
## Verification
- `just test -p codex-core
auto_compact_runs_after_resume_when_token_usage_is_over_limit
auto_compact_counts_encrypted_reasoning_before_last_user
auto_compact_runs_when_reasoning_header_clears_between_turns
responses_lite_compact_request_uses_lite_transport_contract`
## Summary
- Strip image `detail` fields from every Responses Lite request.
- Apply stripping to message images and function/custom tool-output
images.
- Transform only the formatted request copy without mutating stored
history.
- Preserve image URLs byte-for-byte, including HTTP(S) URLs, without
downloading, validating, or resizing them.
- Preserve all image `detail` fields for non-Responses-Lite models.
## Motivation
Responses Lite does not support image `detail` tags, so Codex must omit
them whenever `model_info.use_responses_lite` is enabled. This transport
requirement is independent of the `resize_all_images` feature.
Stored history retains the original detail values. This keeps
request-specific formatting isolated from conversation state and
preserves the information for local image preparation and
non-Responses-Lite requests.
#### [git stack](https://github.com/magus/git-stack-cli)
- ✅ `1` https://github.com/openai/codex/pull/27245
- ✅ `2` https://github.com/openai/codex/pull/27247
- 👉 `3` https://github.com/openai/codex/pull/27246
- ⏳ `4` https://github.com/openai/codex/pull/27266
## Summary
- send `X-OpenAI-Internal-Codex-Responses-Lite: true` on HTTP Responses
requests and WebSocket upgrade requests when model metadata enables
Responses Lite
- use client metadata when sending it over the websocket
This PR is stacked on #26490.
## Why
The Responses Lite marker is request-scoped for HTTP but
connection-scoped for Responses-over-WebSocket because it is carried on
the upgrade request. Reusing a cached socket opened for the opposite
mode would therefore send the wrong transport contract.
## Validation
- `just test -p codex-core responses_lite`
- `just test -p codex-core
responses_websocket_reconnects_when_responses_lite_mode_changes`
- `just fix -p codex-core`
- `just fmt`
## Summary
Responses Lite does not execute hosted Responses tools, so models using
it must route web search and image generation through Codex-owned
executors & standalone Response's API endpoints.
This PR is stacked on #26487.
## Validation
- `cargo test -p codex-core responses_lite_ --lib`
- `cargo test -p codex-core
standalone_executors_remain_hidden_without_flags_or_responses_lite
--lib`
- `cargo test -p codex-core
hosted_tools_follow_provider_auth_model_and_config_gates --lib`
- `cargo test -p codex-web-search-extension -p
codex-image-generation-extension`
- `cargo test -p codex-app-server --test all standalone_`
- `cargo fmt --all -- --check`
