## What changed
- Make `ThreadEnvironments` the source of truth for live environment selections and use it when building configuration snapshots, permission profiles, per-turn configuration, and MCP refresh inputs.
- Keep settings previews side-effect free while applying accepted environment updates consistently to subsequent turns.
- Move `EnvironmentConfig` into `codex-protocol` so environment ownership no longer depends on a core-only type.
## Testing
- Cover environment previews and snapshots, accepted and rejected steer updates, and active-turn environment stability.
GitOrigin-RevId: 7bcf8fb5df1215f720e4e9c419541a51a871aa5e
## Why
When an MCP server rejects existing OAuth credentials, reporting that the server
is merely not logged in obscures that the user needs to authenticate again.
## What changed
Pass the MCP startup failure reason into error formatting and report that the
server requires OAuth reauthentication when appropriate. Preserve the existing
recovery hint for either `codex mcp login` or the client's OAuth sign-in flow.
## Testing
Cover the reauthentication message for both login flows and verify it in the
streamable HTTP OAuth round-trip test.
GitOrigin-RevId: 6f6d5fe7519b1a476f8b70d976223b2ea1ec938e
## Why
App tool file arguments could read and upload files without applying the active
filesystem sandbox policy.
## What changed
- Apply the effective filesystem policy, including session and turn grants, when
reading metadata and streaming files for upload.
- Reject uploads before contacting the files endpoint when the selected path is
denied.
- Report an error when the executor cannot provide sandboxed file streaming for
a restricted policy.
## Testing
Added integration coverage showing that restricted policies allow permitted
files and reject denied files before upload.
GitOrigin-RevId: 63b239c5066dcb9d18b5050089c659fb2a784909
## What changed
- Classify simple PowerShell `Get-Content` commands, including `gc` and `type` aliases, as file reads while preserving Windows paths.
- Reuse the shared classification for implicit skill invocation detection on Windows and render recognized commands as `Read <file>` in the TUI.
- Leave commands with unsupported flags, multiple operands, wildcards, or expressions unclassified.
## Testing
- Cover supported and rejected PowerShell forms, Windows executor skill detection, and the TUI read summary.
GitOrigin-RevId: 4e8f5470f2ae31c08d74091f9634c2926e516ccf
## What changed
- Add a shared, read-only `ConversationHistorySnapshot` capability to the extension API.
- Include the snapshot in `ToolStartInput`, preserving conversation order while excluding contextual user messages.
- Avoid acquiring a history snapshot when no tool lifecycle contributors are registered.
## Testing
- Verify snapshots share existing response items, remain stable as history changes, and filter contextual user messages.
- Verify tool-start callbacks receive the history available for successive tool calls.
GitOrigin-RevId: 822cae33781dd876ea628f104be08d8a449a4900
## What changed
- Capture accepted, successful `node_repl` results from Code Mode and include them as bounded, untrusted evidence in Guardian review prompts.
- Enable the enhanced transcript through `guardian_enhanced_node_repl_transcripts` or when the selected model requires automatic Node REPL review.
- Keep this evidence out of the parent model history, exclude encrypted and failed results, and avoid resending admitted evidence when a Guardian session is reused.
- Clear retained evidence and invalidate review sessions when a thread is rolled back.
## Testing
- Add unit coverage for evidence ordering, escaping, truncation, and empty responses.
- Add an integration test covering feature-disabled, feature-enabled, and model-required behavior, including filtering and review-session reuse.
GitOrigin-RevId: edc3dca5d5b88d472a492f35531ec46889a89d72
## Why
Hooks supplied as managed requirements must not be silently skipped when their
handlers cannot be loaded.
## What changed
- Fail session and app-server thread startup when an enabled managed requirement
contains an invalid matcher, an empty command, or an unsupported handler type.
- Keep load failures for ordinary managed configuration hooks as warnings, and do
not enforce managed hook requirements while the hooks feature is disabled.
## Testing
Added hook-engine, core session, and app-server coverage for valid and invalid
managed hook requirements.
GitOrigin-RevId: 91a23b0c1d85e143aba6aabe874c5274e52fc6b2
## Why
Guardian review sessions must not gain access to paths that the parent turn is
not allowed to read.
## What changed
- Derive Guardian permissions by intersecting managed parent filesystem rules
with read-only access, preserving denied paths and restricting network access.
- Offer Guardian execution tools only when a managed sandbox can enforce those
rules.
- Include the selected environment IDs in the review-session reuse key so a
session is not reused across different environment sets.
## Testing
Update the Guardian reuse integration test to verify that a review cannot read
a parent-denied file or write a local file while consecutive reviews still
reuse the same session.
GitOrigin-RevId: 20f17a6c379f1eda651e8508459d642a51e4ce94
## What changed
- Add `RecoverTurnRequest` and `CodexThread::recover_turn_if_idle` to resume an interrupted regular turn with its existing turn ID and updated thread settings.
- Treat recovery separately from automatic idle work so it can resume in Plan mode without injecting an empty user message.
- Reject recovery while another turn is active without applying settings or queuing input.
## Testing
- Cover successful Plan-mode recovery, turn ID preservation, and the absence of an empty user message.
- Cover active-turn rejection and verify that it leaves settings and pending input unchanged.
GitOrigin-RevId: 2376fdc78b5d48b571633981960741ba269ab1ef
## What changed
- Represent blocked network requests as approval actions so permission hooks,
automatic review, and user review use the common approval flow.
- Route network requests using the active turn's review settings, including for
background terminals started by an earlier turn.
- Record the final applied network decision in tool telemetry without exposing
the destination or assigning an approval source.
- Persist deny amendments and keep the blocked request denied.
## Testing
Added coverage for strict automatic review, cross-turn background network
requests, deny amendment persistence, and destination-safe telemetry.
GitOrigin-RevId: a2a9d106962f407ed93f4d198f40ced15f090b8e
## What changed
- Delete the unused standalone `apply_patch` instruction template and its
`codex-prompts` export.
- Simplify prompt-caching coverage to assert that requests use the model's base
instructions.
GitOrigin-RevId: 8c0dc9426d9ac0184d587272622db608a75e8436
## 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
## Why
World-state snapshots and merge patches are keyed collections of sections. Allowing
their persisted `state` field to contain any JSON value required replay code to
handle shapes that cannot represent world state.
## What changed
- Type `WorldStateItem.state` and snapshot patches as JSON object maps.
- Reconstruct full snapshots directly from those maps and apply patches without
fallible arbitrary-value conversions.
- Regenerate the app-server protocol schema for the object-only representation.
GitOrigin-RevId: 3d7662b74f3dd1f3ccc5fdd0200074c13a73cbe5
## What changed
- Add fractional Unix creation times to locally authored user, developer, agent, and tool-output items when they enter durable conversation history.
- Preserve any creation time already supplied with an item across subsequent requests, remote compaction, and resumed history.
## Testing
- Cover timestamp assignment and preservation in session, client, tool, agent-spawn, and remote-compaction tests.
GitOrigin-RevId: 431d1770b9746005c808bc0a43953845166d68ad
## Why
Skill catalogs can present shortened package locators, but callers previously had
to expand those aliases before reading a skill.
## What changed
- Resolve catalog aliases automatically when `skills.read` looks up a
model-visible executor or orchestrator skill package.
- Update skill prompts and tool documentation to tell models to pass the listed
package locator directly.
## Testing
- Exercise reading an executor skill through its shortened package locator when
the skills catalog exceeds its context budget.
GitOrigin-RevId: d1cdfd64002510b616146929deb5b7077850b951
## What changed
- Use each `ExternalAuth` provider's error classification for resolve, refresh,
and validation failures.
- Allow runtime providers to be replaced, clearing any recorded permanent
refresh failure after the replacement resolves successfully.
- Preserve workload identity as immutable, host-managed authentication while
sharing external ChatGPT credentials through the process-local store.
## Testing
- Cover provider replacement after a permanent failure, provider-defined error
classification, workload identity immutability, and refreshed headers after
an unauthorized response.
GitOrigin-RevId: ec75cf9224dc82d3fd10063606c724e3b06fb1e7
## Why
A single execution can trigger multiple network approval reviews. Its tool
result should reflect the latest specific rejection.
## What changed
- Let each explicit network review outcome replace the previously recorded
outcome for the execution.
- Keep generic blocked-request messages as fallbacks that cannot overwrite an
explicit review outcome.
## Testing
- Add unit coverage for outcome precedence.
- Add an integration test that rejects two network requests from one execution
and verifies that only the latest rejection is returned.
GitOrigin-RevId: 644a01e5c49855adcdc48ba8f91baededce26875
## What changed
- Provide matching local plugin commands with a sandbox-writable temporary output file through `CODEX_PLUGIN_METRICS_OUTPUT` when analytics is enabled.
- Validate successful command output against the plugin's `analytics.yaml` declaration, including measurement names, enum dimensions, finite values, duplicate rows, and size limits, before publishing analytics events.
- Keep the output path reserved from user overrides and clean up the temporary file after execution.
## Testing
- Cover output validation, limits, cleanup, sandbox permissions, environment handling, and path replacement.
- Verify measurement collection through both classic and zsh-fork shell runtimes.
GitOrigin-RevId: 88af0f87dc2f207fcbcca6af498f5c940d79349d
## What changed
- Extract `x-models-etag` from `codex.response.metadata` events and emit it as a `ModelsEtag` response event.
- Stop reading or reporting the model ETag from WebSocket upgrade headers.
## Testing
- Update the WebSocket response-stream test to deliver the ETag through a metadata event and verify that it is emitted.
GitOrigin-RevId: 9b9cff3d8a0a914549aca62d8d316483a9a47f69
## What changed
- Add `http_headers_helper` configuration for local streamable HTTP MCP servers. The configured shell command runs once per connection and returns a JSON object of headers that is cached across requests.
- Apply helper headers to MCP startup and OAuth flows while restricting them to the server origin, stopping redirects, rejecting reserved or duplicate headers, and enforcing output and execution limits.
- Reject helpers for remote or managed-disabled servers, use the local environment working directory, and redact helper commands from `codex mcp list` and `codex mcp get` output.
## Testing
- Cover configuration validation, helper lifecycle and output parsing, origin isolation, OAuth discovery and token refresh, managed requirements, environment selection, and CLI redaction.
GitOrigin-RevId: 84e0e26ce75520b0869d37c72b1678e033bd6818
## What changed
- Mark developer messages received from clients with `client_authored` harness
metadata when `retain_client_developer_messages` is enabled.
- Carry that provenance through pending input and persist it alongside rollout
response items without adding it to provider requests or the serialized
`TurnInput` payload.
- Preserve existing behavior for unannotated response items and when the
feature is disabled.
## Testing
- Cover client item injection before and during turns, additional application
context, rollout replay, image resize notices, and serialization boundaries.
GitOrigin-RevId: f385c177732becde732272e4b8440eb91f5c1039
## What changed
- Parse `node_repl_auto_review_required` and `node_repl_disabled` from model catalog entries and include their values in each turn's Responses API metadata.
- Treat both fields as reserved metadata so client-provided values cannot override the selected model's policy.
- Use the selected review model's catalog entry when building metadata for review turns.
## Testing
- Cover metadata propagation across model switches, review turns, Responses API requests, and MCP tool calls.
GitOrigin-RevId: c1f63426eeb8e559abff439fbc618716a4908aff
## Why
`parent_turn_id` identifies the immediate caller of a nested request, but not the
top-level turn that initiated a multi-level chain of work.
## What changed
- Add `root_turn_id` to turn state, submissions, and Responses API metadata.
- Propagate the root through spawned agents, delegated work, review sessions, and
turn-triggering inter-agent messages.
- Omit the root when background work has no user turn or combined input makes the
root ambiguous.
## Testing
Added coverage for nested agent resumes, reviews, mailbox delivery, steered input,
and reserved metadata handling.
GitOrigin-RevId: 60057db2ee81f4efefa946a9f63c74ff98b93929
## Why
Subagents can reuse cached MCP tool definitions without opening another server
connection immediately, but marking a server as required previously forced eager
startup even when its cached tools were available.
## What changed
- Allow required MCP servers with usable cached tools to remain dormant under
the lazy startup policy.
- Treat those cached tools as satisfying required-server validation and tool
catalog capture until the server is needed.
- Preserve eager startup for required servers without cached tools and start a
dormant server when one of its tools is called.
## Testing
Extend the cached HTTP MCP subagent test to cover both optional and required
servers, verifying that the required server stays dormant until its cached tool
is called.
GitOrigin-RevId: 48ea20b9ae447eef27461caee2320ea78465bb6a
## What changed
- Require delegated Codex sessions to use the `never` approval policy and reject
delegate creation with any prompt-capable policy.
- Stop forwarding delegate approval and permission requests to the parent
session. Approval-requiring commands and MCP tool calls are denied within the
delegate instead.
- Skip prompts for missing skill MCP dependencies when approvals are disabled.
## Testing
Add coverage for review and Guardian delegates to verify that command
escalations, MCP approvals, and skill dependency installation do not prompt or
execute approval-gated actions.
GitOrigin-RevId: fee96a97624352cd25c904592ba7eebe2ae3fd63
## Why
The search tool integration test suite was disabled entirely on Windows.
## What changed
- Remove the suite-wide Windows exclusion and build test fixtures with automatic environment selection.
- Configure stdio MCP fixtures with environment-aware server paths and environment IDs for local and remote runs.
- Skip the three stdio MCP cases that still require a native Windows test server when running through Wine.
GitOrigin-RevId: cf6f919bed28722996680dd0a085c1d1f80e4dcb
## Why
Executor skills required a `skills.list` lookup before their contents could be
read, even when the catalog already identified the skill.
## What changed
- Render executor skill catalog entries as package locators, including shortened
locators when skill roots are aliased.
- Tell the model to pass those packages directly to `skills.read`, while keeping
`skills.list` as the fallback when no package is available.
- Use the shorter package locators when applying the skills context budget.
## Testing
Update catalog, aliasing, budget-pressure, and selected-skill coverage, including
an executor package ID containing a literal backslash.
GitOrigin-RevId: 2ace5e527dc4f29651a8f3214475ccc90d52c73f
## What changed
- Represent MCP tool calls as approval actions and route them through the
session-level approval flow for permission hooks, reviewer selection,
rejection handling, and resolution telemetry.
- Preserve MCP-specific user prompts, session and persistent approval choices,
and the approval policy and reviewer captured for the tool call.
## Testing
- Add coverage for permission hooks resolving MCP calls before user or
automatic review, persistence choices, captured policy routing, and MCP turn
metadata with strict automatic review enabled.
GitOrigin-RevId: 8e134b3d17a19dc62b3b56076d2cd05a54c9f638
## What changed
- Include the connector ID, action name, and model in file creation requests for hosted app tool calls.
- Use the file size returned by upload finalization when available, while falling back to the local size for older server responses.
- Keep upload finalization requests empty for compatibility with older servers.
## Testing
- Cover hosted app upload metadata and legacy finalization responses.
GitOrigin-RevId: 1bc834736db4fe3515f8224965cde0e5d6955ca3
## What changed
Add integration coverage verifying that Guardian receives both the user prompt
and the outer code mode `exec` source when reviewing a nested escalated
`exec_command` call.
GitOrigin-RevId: e78e9d4d69e7ebccc935c548565a07600659f65a
## What changed
- Resolve user message admission when Core accepts the input as a new turn or a steer, without waiting for rollout persistence.
- Remove persistence- and hook-specific admission errors and task bookkeeping.
- Delete queued messages after Core accepts them for turn processing, including messages subsequently stopped by a prompt hook.
## Testing
- Update concurrent admission and queue service tests for acceptance-based admission.
GitOrigin-RevId: 7dcc311cfecd3d710733b420f2add546edb86153
## What changed
- Permit immediate user-message admission to start a turn when `Op::UserInput`
has no items. The turn can proceed with its generated environment context and
does not emit a user-message item.
- Continue rejecting empty input for persisted admission, where there is no
user message to persist.
## Testing
- Cover successful empty-input turn admission and completion.
- Cover prompt rejection of empty persisted admission.
GitOrigin-RevId: d534cf0e228e3bc77f45fe6d9bd25c9073216fbd
## What changed
- Detect executor-owned skill document reads and script executions across native and URI-based working directories.
- Match skills only within the active execution environment while preserving host skill detection for local commands.
- Emit resource-backed implicit invocation events and deduplicate repeated accesses within a turn.
## Testing
- Add unit coverage for document reads, script executions, and environment-scoped matching.
- Add an integration test for environment selection, resource-backed analytics, and repeated-access deduplication.
GitOrigin-RevId: f78a48c3a4766fe8775bd88926b45a76761f6af8
## Why
Threads that share an executor environment can require different capability roots and login-shell policies. Treating readiness configuration as executor-wide can expose one thread's settings to another.
## What changed
- Add `CodexThread::environment_ready` and `EnvironmentConfig` so hosts can install capability roots and login-shell policy for an exact thread, environment, and working-directory attachment.
- Validate attachment readiness updates, merge ready attachment roots with persisted thread roots, and refresh MCP capabilities when those roots change.
- Preserve installed environment policy across thread settings updates and child-thread inheritance while resetting it when the selected working directory changes.
## Testing
- Cover attachment config inheritance and reset behavior.
- Verify that threads sharing an executor retain independent model-visible capability roots and login-shell tool schemas across updates.
GitOrigin-RevId: 60e7a296b3e41b835b0413aa2837451e8a55c230
## What changed
- Emit skill invocation analytics when a resource-backed skill is explicitly selected or its main resource is successfully read from the first page.
- Preserve provider-supplied skill IDs and user scope when available, and derive a stable ID from the main resource otherwise.
- Deduplicate repeated implicit reads of the same main resource within a turn.
## Testing
- Extend the orchestrator skill integration test to cover explicit and implicit invocation events, stable fallback IDs, failed reads, and repeated-read deduplication.
GitOrigin-RevId: 7d8453b31b5a2205847e65cda2c46183d6c97b45
## What changed
- Set `store` to `false` for every Responses request, including requests sent
through Azure providers.
- Remove the provider-specific storage check and simplify request construction.
- Update the Azure request test to verify that storage is disabled while
prefixed item IDs remain unchanged.
GitOrigin-RevId: 1c71cb80880058cb26789112f03269b73f0645b9
## What changed
- Wrap response items with optional harness-owned metadata while keeping the persisted response payload shape backward compatible.
- Store compacted-history metadata in an aligned sidecar and reject malformed sidecars.
- Carry metadata through history normalization, compaction, resume, fork, truncation, migration, and rollout recording without sending it to model providers.
## Testing
- Cover legacy rollout compatibility, metadata serialization and validation, compaction retention, and resume/fork reconstruction.
GitOrigin-RevId: 17a6127c9048ff984cb4df4d97c0751a38c29f5f
## What changed
- Add a host-owned external auth source that runtime account APIs cannot replace,
clear, or log out, and keep its credentials process-local instead of writing
them to auth storage.
- Let configured providers classify refresh failures. Preserve cached credentials
after permanent reload failures while retaining transient behavior for runtime
providers.
- Compare external ChatGPT token data when detecting auth changes so a refreshed
access token is applied to a retried request.
## Testing
- Cover configured-auth immutability, process-local storage, permanent reload
failures, runtime error classification, and refreshed headers after a `401`.
GitOrigin-RevId: c6d70a39325c8ba6ca65ae68e12b55609f00a876
## What changed
- Add `inject_response_items_for_turn` for callers that inject Responses API
items immediately before admitting user input. It defers the rollout flush so
the injected items and user input are persisted together by turn admission.
- Keep `inject_response_items` behavior unchanged by flushing after it delegates
to the new helper.
- Update the turn-start persistence test to exercise the turn-aware path.
GitOrigin-RevId: 8349b65f937af2b2a95d36b3fd73d862d38e5fd9
## What changed
- Add `auto_review_enabled` to serialized turn metadata for regular and review turns.
- Derive the value from approval-policy routing and reserve the metadata key so client-provided metadata cannot override it.
## Testing
- Cover enabled metadata, reserved-key handling, Guardian review requests, and updated compaction request snapshots.
GitOrigin-RevId: 52773e2bf7d4be251f8466332de9f9c9869dd084
## Why
Cross-platform remote `apply_patch` calls were rejected when filesystem writes
were restricted because patch verification and writes could not be safely
performed against executor files.
## What changed
- Route intercepted and direct remote patches through the executor-managed
filesystem sandbox, including the configured workspace roots.
- Select the restricted-token sandbox for Windows executor paths when no
Windows sandbox level was configured.
- Fail closed when an executor cannot enforce the requested sandbox, and treat
executor-managed access failures as sandbox denials so approval can retry the
patch without sandboxing.
## Testing
- Cover sandboxed remote patches, denied writes, approval retries, Windows
sandbox selection, and executor filesystem enforcement.
GitOrigin-RevId: caddeed0b266c456a689080a14a3a58e2bd7887c
## What changed
- Remove effective-config lockfile export, replay, and validation from session startup.
- Remove the `debug.config_lockfile` settings and generated schema entries.
- Remove feature-config materialization helpers that were only used to create lockfiles.
GitOrigin-RevId: a8c07c1c06325b3ec3dae9a97c36c2488d37df25
## Why
Subagents should be able to use known HTTP MCP tool definitions without opening a connection until a tool is actually called.
## What changed
- Add streamable HTTP configurations to the process-scoped MCP tool catalog cache when their authentication identity can be derived safely.
- Fingerprint transport settings, relevant environment variables, protocol mode, plugin status, and client capabilities so catalogs are reused only across equivalent connections.
- Keep OAuth and other dynamically resolved credential configurations out of the shared cache.
## Testing
- Add an integration test proving that a subagent receives cached HTTP tools without reinitializing the server, then starts its own connection when it calls one.
GitOrigin-RevId: bb2787e29e9b71993def31aafd1f0d8f1b728d26
## What changed
- Reject invalid or unsupported image data before producing tool output, so
non-image file contents are not exposed through code mode.
- Preserve valid image bytes and metadata while leaving image preparation and
resizing to the history insertion path.
## Testing
- Cover invalid images in both code mode and standard `view_image` calls.
- Verify that code mode preserves PNG bytes, dimensions, EXIF orientation, and
metadata.
GitOrigin-RevId: 07343ed10b781d0ce0ffb5b24432658be4c046e3
## What changed
- Add `PersistContext` to the thread-store persistence contract so stores can
identify persistence requested immediately before model sampling. A
`TurnStart` request may be enqueued in the background when later flush and
shutdown operations fence it and report any failure; all other persistence
remains synchronous.
- Use the turn-start context only for the initial input of a regular turn, while
admission acknowledgments, steered input, and other persistence paths keep
the standard durability behavior.
- Flush pending metadata before turn-start persistence and ensure shutdown is
still attempted if that metadata update fails.
## Testing
- Verify that developer instructions and user input are persisted before the
model request completes for a default paginated-history thread.
GitOrigin-RevId: 162f0ec796a61aebe66ca0b909fbcccec3047b85
## Why
Background refreshes previously warmed only the on-disk cache, so new sessions in the same process continued using the startup snapshot.
## What changed
- Make `CloudConfigBundleLoader` retrieve the latest shared bundle on each configuration load.
- Update the in-memory bundle after successful refreshes while preserving the last successful bundle when a refresh fails.
- Stop refresh work when its loader is replaced or its final clone is dropped.
## Testing
- Cover refreshed requirements and managed configuration in later sessions.
- Cover concurrent initial loads, refresh failures and recovery, bundle clearing, and refresh-task cancellation.
GitOrigin-RevId: ae3d79b575bad71a1eed370cee6dc66dc022ffa8
## What changed
- Pass image bytes from `view_image` through unchanged for both direct and code-mode calls, leaving decoding and resizing to the shared history-insertion path.
- Represent invalid image data with the existing image-omission placeholder instead of returning a tool error.
## Testing
- Update the `view_image` integration test to cover placeholder output for invalid image data.
GitOrigin-RevId: 62863defd4815efb8a7725712fd583ad81db3fbb
## What changed
- Add `responses_api_metadata` for product-owned key/value metadata included in
every Responses API turn metadata payload, including parent and subagent
requests.
- Limit the map to 16 entries, ASCII identifier keys of at most 64 bytes, and
values of at most 128 bytes. Reject reserved Codex metadata keys and ignore
this setting in project-local configuration.
- Give configured product metadata precedence over app-server client metadata
while keeping it out of metadata sent to external MCP servers.
## Testing
- Cover reserved-key validation, metadata precedence, MCP isolation, and
propagation to parent and subagent Responses API requests.
GitOrigin-RevId: a7be798294fde25145ab375a468321bb4e4a49f1
## What changed
- Decode image data in the `view_image` handler and return a clear error for invalid or unsupported input.
- Re-encode code-mode images as PNG pixel data while preserving original image bytes for direct tool calls.
- Cover code-mode PNG output and rejection of invalid image data.
GitOrigin-RevId: 0a00e595ab749c19eab866a22f6577b6627e19f1
sayan-oai