## Why
Skill tools depended on World State rendering to initialize their catalogs and could return `skill catalog is not ready for this step` before rendering completed.
## What changed
- Add an asynchronous `ToolContributor::prepare_for_step` hook and await all contributors before constructing tools.
- Prepare immutable skill catalogs, aliases, plugin policy, and configuration for each step. Tools, invocation detection, and World State rendering consume the prepared state without relying on rendering to perform discovery.
- Apply configuration reloads to subsequent steps while preserving live authorization checks for skill reads.
## Testing
Add coverage for preparation completing before tool construction and World State rendering, skill tools working before rendering, catalogs remaining stable across steps, and configuration reloads during discovery.
GitOrigin-RevId: 1fb95c58c412488353f3bd4403824d6d1476d3d0
## Why
A skill can be available from Cloud and multiple executor environments. Reading its instructions needs to expose where supporting files live and allow discovery of locations omitted by response limits. Package aliases also need to keep identifying the same roots as catalogs change.
## What changed
- With executor capability discovery V2, add `skills.installations` to list enabled locations with source filtering and pagination, without reading skill contents.
- Let `skills.read` select Cloud or a specific executor environment through `source`. Return bounded installation metadata and an `installations_truncated` flag so callers can retrieve omitted locations.
- Share bounded, append-only alias assignments between catalog rendering and tools within a live thread. Preserve each step's alias snapshot and render only root mappings used by its catalog entries.
- Use discovery-root metadata when constructing executor skill locators, with a fallback when it is absent. Preserve the legacy read response and tool set outside discovery V2.
## Testing
Add coverage for installation filtering and pagination, response budgets, source-specific reads and cursors, and alias stability across catalog and plugin changes. Add an end-to-end scenario that discovers an omitted installation and reads its instructions from the selected environment.
GitOrigin-RevId: a04e51e8242b21288d9d7b822780f9f1e093151d
## What changed
- Build executor skill catalogs from discovery V2 inventories without reopening host paths or falling back to legacy discovery.
- Merge Cloud and executor skills by remote plugin identity and skill name, retaining Cloud metadata and accepted provider read routes. Apply plugin selection and disablement before merging.
- Share a stable catalog across each step's rendering, list/read tools, and explicit and implicit skill invocations.
- Preserve unmatched executor entries when Cloud catalogs are unavailable or partial; only complete Cloud catalogs disable unmatched remote entries.
- Bind discovery caches to captured environments and executor sessions, and refresh MCP when V2 inventories change. Preserve pending invalidations when forced MCP refreshes fail.
## Testing
Add regression coverage for V2 inventory sharing and refresh, environment isolation, catalog merging, partial Cloud results, disabled plugins, and catalog consistency across steps and read routes.
GitOrigin-RevId: 842bdcbc9e19364dd69a9abf9e48330b7425a76c
## What changed
- Upload generated images to the attachment store and expose `fileId` in image-generation items when available, with inline `result` fallback on upload or decoding failure.
- Preserve file references through legacy events, persisted rollouts, thread history, and task output summaries. Keep model-facing image preparation separate.
- Add attachment request tags and mark generated-image uploads with `usage=image_gen`, preserving the thread's ephemeral setting.
- Update public schemas and SDK types to accept either image representation, retain the Python `ImageGenerationThreadItem` alias, and prefer `fileId` when reading records containing both fields.
## Testing
Add coverage for file-backed generation and rollout persistence, legacy history replay, inline and transitional serialization, task output visibility, and Python SDK alias compatibility.
GitOrigin-RevId: f7a2bb5707e2f277348a547a988bc33c8e96d891
## What changed
- Add the disabled-by-default `executor_capability_discovery_v2` feature to acquire `capabilities/discoverV2` inventories from supporting remote executors using each selected environment's working directory and sandbox.
- Share snapshots with MCP and world-state contributors and skill providers without activating discovered plugins or publishing discovered skills to the model.
- Cache inventories by environment instance, executor session, working directory, and sandbox. Coalesce concurrent requests, refresh the cache at turn start, retry transient failures, and refresh MCP projections after recovery.
- Resolve the system skills root in the executor and pass it explicitly to capability location discovery.
## Testing
Add coverage for feature gating, unsupported executors, inert inventories, cache reuse and eviction, turn refreshes, failure recovery, executor replacement, and system skill locations.
GitOrigin-RevId: 1bdca28fa7f17622b27e2713ab3dcc0c13426889
## Why
Environment changes and overlapping catalog refreshes can cause a step to use another step's selected plugins or executor skills. Model context and skill tools need to agree on the capabilities captured for that step.
## What changed
- Resolve selected plugins from each step's ready capability roots, honoring disabled plugins, and retain the snapshot with the step's extension data.
- Use that snapshot for skill attribution in World State and the first step's active-plugin telemetry.
- Return executor skill catalogs directly from refresh so overlapping requests render their own results while retaining thread caches.
## Testing
Add regression coverage for overlapping executor catalogs and environment changes during step preparation. Verify that `skills.list` retains the original step's skills, the next step advertises the new skills, and disabled executor and plugin skills remain absent from model context.
GitOrigin-RevId: 37d3cbe8c7e062fd06290aa985ada4d3b3462d43
## Why
Executor skill reads need to use the environments and permissions captured for the current step, including newly approved grants. Cached continuation pages must remain bound to the filesystem and permissions that produced them.
## What changed
- Supply borrowed `EnvironmentAccess` to turn-input contributors and extension tools, with session and originating-turn grants already applied.
- Require executor skill reads to use filesystem access from an environment available to the callback, and replace separate optional read contexts with `SkillReadContext`.
- Bind skill pagination snapshots to `EnvironmentAccessKey`, which identifies the source filesystem and callback permissions.
- Route image-generation filesystem operations through the same accessor.
## Testing
Extend skill-read integration coverage to verify that a denied reference becomes readable after a turn-scoped grant is captured by the next model step. Update Windows coverage to verify that restricted reads fail when the executor cannot enforce a sandbox, and add a test requiring turn environment selection before exposing capability roots.
GitOrigin-RevId: 825b49302319965835d61c77fc5bcdb951e10543
## What changed
Return snapshots and model-visible fragments together from world-state rendering, and use those snapshots for history baselines, step updates, compaction, and new context windows.
Update `WorldStateSectionContribution` so its renderer returns an optional replacement snapshot and an optional fragment. A missing snapshot preserves stored section state, even when retained history requires a fresh render; a null snapshot removes the section. Derive step patches from the history baseline rather than a separately captured live world state.
Adapt skills and Git attribution contributors to the new contract.
## Testing
Add coverage for skipped snapshot updates, explicit section removal, changed-state patch replay, unchanged-state deduplication, and matching live and persisted checkpoints when starting a new context window.
GitOrigin-RevId: af71606a278358ae937853cb76e8a019a501408e
## Why
Shadow skill selection runs synchronously during turn input construction, making turn preparation wait for experimental rankings.
## What changed
Run ranking on background blocking workers with a process-wide limit of two concurrent rankings. Wait for capacity in the background and hold each slot until its blocking worker finishes, even if the async evaluation is cancelled.
Freeze catalog, query, and relevance history at turn start. Record eligible invocations immediately for future turns, then score queued observations against the frozen rankings once they are ready, including observations queued before the turn state is dropped.
## Testing
Add tests for turn preparation and history updates while ranking is blocked, deferred invocation scoring against each turn's history, and shared ranking capacity that remains occupied until cancelled workers finish. Update existing metric assertions to collect asynchronous observations across snapshots.
GitOrigin-RevId: f7776e9aaeb45d3a792de167abbe35f7ec5a513e
## Why
Skills available from both cloud and executor providers consume duplicate catalog space, leaving less room for descriptions of unique skills.
## What changed
- Prefer model-visible cloud skills over executor listings with the same `plugin:skill` name before allocating the metadata budget.
- Preserve aliases from the full visible executor inventory so filtering duplicates does not renumber remaining packages. Continue choosing full locators when they fit the budget better.
- Keep executor packages available through `skills.list` and `skills.read`, and retain executor listings when cloud skills are disabled.
## Testing
Add regression tests and a model-request snapshot covering description retention, stable aliases across turns, executor availability changes, package reads, and full-locator selection after deduplication.
GitOrigin-RevId: 477e4cf16b8968dbe61438dd5af1eca9cbfa78c8
## What changed
- Add callback lifetimes to extension `ToolCall`, `ToolEnvironment`, turn-input context, and skill-read request types.
- Require extension tool executors to handle calls for any invocation lifetime and tie their returned futures to that lifetime.
- Update built-in extensions, adapters, and tests to use the lifetime-scoped APIs without retaining host-owned environment capabilities.
GitOrigin-RevId: aca9ce3a1b6870df550bc84ec9308cc65533f161
## Why
Short continuation prompts such as `continue` do not contain enough context for
skill selection on their own.
## What changed
- Add the `task_context_fusion_v1` shadow selector, combining the current request
with up to two prior substantive requests and recently relevant skills.
- Record explicit skill intent and successful skill invocations for future turns,
while excluding same-turn observations from predictions.
- Bound retained requests, augmented queries, and skill history, including safe
truncation at UTF-8 character boundaries.
## Testing
Add unit and extension tests for continuation prompts, explicit intent, turn
isolation, cold thread state, bounded history, and unchanged control selectors.
GitOrigin-RevId: 72eca3f0d64620a0d24e95d5675f126ac982f8c7
Anthony Tafoya