## Why
Switching models can send images from conversation history with `detail: original` to a model that does not support it.
## What changed
Normalize image details on request copies using the receiving model's capabilities. Downgrade `original` to `high` when unsupported, covering user messages and function and custom tool outputs. Preserve stored image details so switching back to a supporting model retains `original`, and continue stripping details for Responses Lite.
## Testing
Expand unit coverage across image detail values and model capabilities. Extend integration coverage for model switches within and between turns, text-only models, and resumed and forked threads, including assertions that persisted tool outputs remain unchanged.
GitOrigin-RevId: 2561651ea74f045e00f708ae53771a41dcd49c94
## Why
Replaying tool outputs under a different model can expand or shrink the history shown to the model if truncation uses the new model's budget.
## What changed
Save the originating history truncation budget on function and custom tool outputs and reuse it during replay, preserving existing tool-specific overrides. Include the existing 20% serialization allowance once, before converting byte budgets to tokens.
Rename the metadata field to `history_truncation_token_limit` while retaining `fallback_token_limit_override` as its serialized name for compatibility.
## Testing
Add regression coverage for resume and fork with different model budgets, including custom tool outputs. Extend unit coverage for existing overrides and byte-budget conversion.
GitOrigin-RevId: a62c8fd3e43198e2252b150fba72f022939c1070
## Why
History recording used the model captured at turn start, so switching models within a turn could apply stale image preparation and tool-output truncation rules.
## What changed
Pass explicit model metadata through conversation recording. Record model responses and tool results using their originating step's settings, and capture the current model for pending input recorded during startup interruption or task completion.
## Testing
Add regression coverage for tool results across a model switch, explicit model selection for plain and annotated history, and image input retained during interruption and completion. Extend model-switching tests to verify that prepared media and item identity survive switching back to a multimodal model in live, resumed, and forked threads.
GitOrigin-RevId: 5bc750c30c334acb9b802cb80fdea01daffa84a1
## Why
After a model change within a turn, tools could still use the turn's original model capabilities, output limits, and telemetry attribution.
## What changed
- Build each step's tool plan from its captured model settings.
- Use those settings for image support and detail, command and MCP output truncation, extension metadata, and tool telemetry.
- Preserve the issuing step's model for delayed command completion events while allowing later `write_stdin` calls to use their own step's output limits.
## Testing
Add regression coverage for model changes within a turn, including tool replanning, Code Mode execution, image handling, MCP tool and resource output limits, extension settings, and delayed command completion.
GitOrigin-RevId: ef991598e89a846889baf770a0c9e12e56886d5d
## Why
Model switches within a turn can leave extension context using stale model metadata. Skill catalogs, context windows, and metric attribution need to match the model captured for each sampling step.
## What changed
- Pass captured model metadata and step-specific telemetry to world-state contributors.
- Use that metadata for skill catalog budgets and usage instructions, preserving configured budget overrides.
- Supply the captured model's usable context window to turn-context contributors, including when rebuilding context.
## Testing
Add regression coverage for model switches during skill discovery, catalog budgets and metric attribution, and extension context windows after `new_context` and retained-step context rebuilds.
GitOrigin-RevId: c51b40b739a380b9767a54ea8c8ee6de45bf01c8
## Why
Model changes during an active turn could leave context using the turn's initial model and settings, even after requests switched to the new model.
## What changed
- Build model, personality, approval, collaboration, app, plugin, and multi-agent instructions from captured step settings.
- Resolve multi-agent policy from the step's effective reasoning effort.
- Use the captured step's context window for full-context metadata and retain that step when rebuilding initial context for compaction.
## Testing
Add regression coverage for model switches updating context without duplicating updates, delegation policy following selected or model-default reasoning effort, and compaction preserving retained context after a model change.
GitOrigin-RevId: 3615c7a3f13f15fdcce9ad13d23311340e0aea88
## What changed
- Update the status heading from the latest usable reasoning line and retain it through tool activity and empty reasoning items. Keep completed reasoning in the expanded transcript only.
- Restore active reasoning after resume, thread switches, and session refreshes, including when earlier events have left the replay buffer.
- Default new embedded TUI threads to `model_reasoning_summary = "detailed"`, honoring explicit summary settings. Keep `concurrent_reasoning_summaries` opt-in and disable it when summaries are `none`.
- Persist the request's captured reasoning summary setting in context updates and local and remote compaction checkpoints.
- Animate status text with a smooth, grapheme-aware shimmer that respects terminal colors and reduced motion.
## Testing
Add regression coverage for reasoning status updates, transcript visibility, resume and buffered replay, outbound summary configuration, and summary settings across all three compaction modes. Add shimmer snapshots and checks for smooth brightness changes and Unicode grapheme preservation.
GitOrigin-RevId: 725c7de20f23166d7a3da6daeca617add5cbc600
## What changed
- Replace `send_user_message_async` with `request_user_input_async`, accepting one or more questions with optional suggested answers while allowing the turn to continue.
- Attach structured question metadata to asynchronous agent messages while retaining readable fallback text, and preserve it through app-server events, thread history, and generated schemas.
- Continue enabling the new tool for model catalogs that advertise either the old or new tool name.
## Testing
- Cover tool registration, question validation, emitted items, continued turn execution, history preservation, and backwards-compatible deserialization.
GitOrigin-RevId: ffc49aebde2e854c3c50a122aa52805fec3fc6b3
## What changed
- Add `approvalsReviewer` to the experimental `turn/settings/update` API.
- Apply reviewer changes to subsequently captured steps and new background approval requests while preserving pending approvals and future-thread defaults.
- Allow reviewer-only updates without `step_model_switching`, while continuing to enforce managed reviewer restrictions and model-required auto review.
- Use an explicit live reviewer update for MCP approvals while retaining refreshed thread defaults for clients that have not set one.
## Testing
- Cover switching between user and automatic review during a live turn, future-turn isolation, and managed-authority rejection.
GitOrigin-RevId: e1216b09c6a7972c2c9eaf4955d8d57d60604ca1
## What changed
- Add model metadata flags for enabling token budgeting and its history-notes extension.
- Apply those activation defaults once at thread startup when the user has not explicitly configured token budgeting, while respecting managed feature requirements.
- Continue resolving model-owned prompts for the active model so model switches can use their own token-budget guidance.
## Testing
- Update the token-budget integration test to verify that model metadata activates the feature without manual configuration.
GitOrigin-RevId: 73a32623eaeabb9243e240c43da7a5e7e93e9a19
## What changed
- Add model message metadata for built-in tool descriptions.
- Use the active step model's catalog description for `send_user_message_async`, including after a mid-turn model change.
- Fall back to the built-in description when catalog metadata is absent, while preserving an explicitly empty description.
## Testing
- Cover catalog serialization, fallback and empty-value behavior, and model changes within a turn.
GitOrigin-RevId: 72b953214ab9708931065321debf12133f8d2d40
## Why
Model settings can change between steps in the same turn. Token-budget defaults,
context-window limits, and model-visible guidance need to stay aligned with the
model captured for each step.
## What changed
- Preserve the turn's original token-budget preferences and resolve model-owned
defaults when each `StepContext` is created.
- Use the step's model to determine context-window availability and token-budget
guidance, while keeping explicit user settings unchanged.
- Emit one-time replacement or removal notices when context-window guidance
changes, including compatibility with previously persisted world-state
snapshots.
- Add `ModelInfo::usable_context_window()` to distinguish reserved-headroom
capacity from the resolved context window and auto-compaction limit.
## Testing
- Cover mid-turn model switches with model defaults, explicit settings, config
reloads, missing context windows, and missing destination guidance.
- Cover unchanged, replaced, removed, blank, and legacy guidance transitions.
GitOrigin-RevId: 91100a9f3625bef8a79ecd158eb028051c309eee
## What changed
- Add optional Browser Use and Computer Use confirmation-policy Markdown to model catalog messages.
- Send the configured documents verbatim in `openai/confirmation_policies` metadata for `node_repl` and `cua_repl` tool calls. Send an empty object when the issuing model has no policies so runtime defaults are cleared.
- Use the issuing step's model snapshot across approval waits, and omit the metadata for other MCP servers and Guardian sessions.
## Testing
- Cover policy serialization, configuration overrides, model changes, approval waits, partial or empty policies, eligible server filtering, and Guardian exclusion.
GitOrigin-RevId: 038c4c262a31fc71986e4a2a947fe9bcbd407acc
## What changed
- Add bundled proactivity and follow-up guidance when `ReasoningEffort::Persistent` is selected.
- Allow model metadata to override or disable the guidance with `persistent_instructions`.
- Track the instructions as world state so effort and model changes replace or retire stale guidance without duplicating unchanged context.
- Tailor approval guidance to `send_user_message_async` availability, rebuild it for forked agents and rolled-back history, and exclude Guardian sessions.
## Testing
- Cover default, overridden, disabled, replaced, and retired instructions.
- Cover model changes, history transitions, agent forks, Guardian sessions, and asynchronous-message tool availability.
GitOrigin-RevId: 78e05d0335a70b385bd069b45edcd4ba570cef91
## What changed
- Add a feature-gated `TurnSettings` operation that can update the model,
reasoning effort, reasoning summary, and service tier for subsequent steps of
a named running turn without changing future thread settings.
- Report whether an update was applied, rejected, or lost its live target.
- Revalidate managed constraints and preserve the turn's admitted approval and
Guardian safety properties before publishing an updated settings snapshot.
## Testing
- Cover sparse updates, step capture and ordering, target replacement, managed
policy changes, model metadata safety, and separation from future settings.
GitOrigin-RevId: ecaaaa95b4fd4ec9d62265bef551582dddb36d78
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