This release introduces generated image output support with workspace-safe storage and portable session blobs, a new tool hook execution model with mandatory phases, and several other feature additions and fixes.
What's New
- Adds streaming support for model-generated media deltas, accumulating complete image bytes in runtime stream results
- Adds workspace media writes with collision-safe naming, MIME-corrected extensions, and no-overwrite publication for generated images
- Adds generated media materialization as workspace files with no-resend history placeholders stored in session JSON instead of raw base64
- Keeps all generated-media writes inside the owning workspace; external, traversal, and symlink-escaping paths are redirected to a sanitized basename
- Names generated media via private
[media-file:]response markers with fallback to user-prompt filename, provider name, orgenerated-N - Renders generated images through manifest-gated authorization, revalidating against the current manifest on every resolution
- Restores generated media from portable session blobs when resuming sessions
- Adds
output_capabilities.imageconfiguration support to resolve image output capability from models.dev metadata - Guards image-output requests across Google surfaces (gateway, direct Gemini API, and Vertex), rejecting custom function tools and structured output before dispatch
- Adds tool hook phases with a fixed mandatory execution order:
tool_input_transformruns first, followed bytool_guard; includes hook deduplication, config validation, and a shared events catalog with centralized contracts - Adds
provider_opts.service_tierfield for OpenAI provider, forwarded unchanged to the underlying API for Fast mode support - Marks lean TUI user prompts with OSC 133 semantic prompt boundaries in terminal scrollback, enabling navigation between turns in supported terminals (e.g., iTerm2); also restores session transcripts when the lean TUI starts with a resumed session
Bug Fixes
- Fixes Gemini session title generation by omitting
thinkingConfigand reserving 128-token reasoning headroom with a separate 50-character visible title limit - Fixes session title selection to keep image-output-capable models eligible as title candidates
- Fixes sanitization and bounding of generated-media metadata
- Classifies generated-media save failures into safe, reportable reasons
Technical Changes
- Reverts "fail fast on foreign-OS paths and explain path resolution" from the filesystem tool
- Moves CI image builds to Docker Build Cloud
- Reverts CI feedback-loop shortening changes (parallel jobs, warm Go cache, Build Cloud pipeline)
- Fixes CI image builds for fork pull requests that lack cloud credentials
What's Changed
- feat(#3996): stream model-generated media deltas by @aheritier in #4023
- docs: update CHANGELOG.md for v1.137.0 by @docker-read-write[bot] in #4212
- feat(openai): support provider_opts.service_tier for Fast mode by @dgageot in #4214
- docs: fix CLI completion, debug visibility, task dev parallelism, DCO clarification by @dgageot in #4215
- docs: auto-update for merged PRs (2026-09-10) by @aheritier in #4216
- chore: update docker-agent-action to v2.0.7 by @docker-agent in #4208
- feat(#3996): add workspace media writes and session provenance by @aheritier in #4024
- ci: move image builds to Docker Build Cloud by @aheritier in #4219
- feat(#3996): save generated media with no-resend placeholders by @aheritier in #4025
- feat(#3996): keep generated media workspace-only with portable session copies by @aheritier in #4026
- feat(#3996): name generated media with private markers and prompt fallback by @aheritier in #4027
- fix(#3996): leave reasoning headroom for Gemini session titles by @aheritier in #4028
- feat(#3996): render generated images from manifest-gated portable blobs by @aheritier in #4029
- ci: shorten the feedback loop (parallel jobs, warm Go cache, Build Cloud) by @aheritier in #4220
- docs(#3996): describe portable generated media and Gemini output limits by @aheritier in #4030
- feat(hooks): tool hook phases — mandatory guards, transforms, dedup and strict output by @dgageot in #4211
- Revert "ci: shorten the feedback loop (parallel jobs, warm Go cache, Build Cloud)" by @dgageot in #4223
- revert: remove foreign-OS path rejection from filesystem tool by @dgageot in #4222
- feat: mark lean TUI prompts in terminal scrollback by @rumpl in #4224
Full Changelog: v1.137.0...v1.138.0