* feat(gateway): implement claim check pattern to prevent OOM on large attachments
* fix: sanitize mediaId, refine trimEnd, remove warn log, add threshold and absolute path
* fix: enforce maxBytes before decoding and use dynamic path from saveMediaBuffer
* fix: enforce absolute maxBytes limit before Buffer allocation and preserve file extensions
* fix: align saveMediaBuffer arguments and satisfy oxfmt linter
* chore: strictly enforce linting rules (curly braces, unused vars, and error typing)
* fix: restrict offload to mainstream mimes to avoid extension-loss bug in store.ts for BMP/TIFF
* fix: restrict offload to mainstream mimes to bypass store.ts extension-loss bug
* chore: document bmp/tiff exclusion from offload whitelist in MIME_TO_EXT
* feat: implement agent-side resolver for opaque media URIs and finalize contract
* fix: support unicode media URIs and allow consecutive dots in safe IDs based on Codex review
* fix(gateway): enforce strict fail-fast for oversized media to prevent OOM bypass
* refactor(gateway): harden media offload with performance and security optimizations
This update refines the Claim Check pattern with industrial-grade guards:
- Performance: Implemented sampled Base64 validation for large payloads (>4KB) to prevent event loop blocking.
- Security: Added null-byte (\u0000) detection and reinforced path traversal guards.
- I18n: Updated media-uri regex to a blacklist-based character class for Unicode/Chinese filename support, with oxlint bypass for intentional control regex.
- Robustness: Enhanced error diagnostics with JSON-serialized IDs.
* fix: add HEIC/HEIF to offload allowlist and pass maxBytes to saveMediaBuffer
* fix(gateway): clean up offloaded media files on attachment parse failure
Address Codex review feedback: track saved media IDs and implement best-effort cleanup via deleteMediaBuffer if subsequent attachments fail validation, preventing orphaned files on disk.
* fix(gateway): enforce full base64 validation to prevent whitespace padding bypass
Address Codex review feedback: remove early return in isValidBase64 so padded payloads cannot bypass offload thresholds and reintroduce memory pressure. Updated related comments.
* fix(gateway): preserve offloaded media metadata and fix validation error mapping
Address Codex review feedback:
- Add \offloadedRefs\ to \ParsedMessageWithImages\ to expose structured metadata for offloaded attachments, preventing transcript media loss.
- Move \ erifyDecodedSize\ outside the storage try-catch block to correctly surface client base64 validation failures as 4xx errors instead of 5xx \MediaOffloadError\.
- Add JSDoc TODOs indicating that upstream callers (chat.ts, agent.ts, server-node-events.ts) must explicitly pass the \supportsImages\ flag.
* fix(agents): explicitly allow media store dir when loading offloaded images
Address Codex review feedback: Pass getMediaDir() to loadWebMedia's localRoots for media-uri refs to prevent legacy path resolution mismatches from silently dropping large attachments.
* fix(gateway): resolve attachment offload regressions and error mapping
Address Codex review feedback:
- Pass \supportsImages\ dynamically in \chat.ts\ and \gent.ts\ based on model catalog, and explicitly in \server-node-events.ts\.
- Persist \offloadedRefs\ into the transcript pipeline in \chat.ts\ to preserve media metadata for >2MB attachments.
- Correctly map \MediaOffloadError\ to 5xx (UNAVAILABLE) to differentiate server storage faults from 4xx client validation errors.
* fix(gateway): dynamically compute supportsImages for overrides and node events
Address follow-up Codex review feedback:
- Use effective model (including overrides) to compute \supportsImages\ in \gent.ts\.
- Move session load earlier in \server-node-events.ts\ to dynamically compute \supportsImages\ rather than hardcoding true.
* fix(gateway): resolve capability edge cases reported by codex
Address final Codex edge cases:
- Refactor \gent.ts\ to compute \supportsImages\ even when no session key is present, ensuring text-only override requests without sessions safely drop attachments.
- Update catalog lookups in \chat.ts\, \gent.ts\, and \server-node-events.ts\ to strictly match both \id\ and \provider\ to prevent cross-provider model collisions.
* fix(agents): restore before_install hook for skill installs
Restore the plugin scanner security hook that was accidentally dropped during merge conflict resolution.
* fix: resolve attachment pathing, defer parsing after auth gates, and clean up node-event mocks
* fix: resolve syntax errors in test-env, fix missing helper imports, and optimize parsing sequence in node events
* fix(gateway): re-enforce message length limit after attachment parsing
Adds a secondary check to ensure the 20,000-char cap remains effective even after media markers are appended during the offload flow.
* fix(gateway): prevent dropping valid small images and clean up orphaned media on size rejection
* fix(gateway): share attachment image capability checks
* fix(gateway): preserve mixed attachment order
* fix: fail closed on unknown image capability (#55513) (thanks @Syysean)
* fix: classify offloaded attachment refs explicitly (#55513) (thanks @Syysean)
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Co-authored-by: Ayaan Zaidi <hi@obviy.us>
* gateway: fix /v1/responses tool schema to use flat Responses API format
* gateway: fix remaining stale wrapped-format tools in parity tests
* gateway: propagate strict flag through extractClientTools normalization
* fix(gateway): cover responses tool boundary
* Delete docs/internal/vincentkoc/2026-03-30-pr-57166-responses-tool-schema-followup.md
---------
Co-authored-by: Michel Belleau <mbelleau@Michels-MacBook-Pro.local>
Co-authored-by: Vincent Koc <vincentkoc@ieee.org>
* gateway: prefer transcript model in sessions list
* gateway: keep live subagent model in session rows
* gateway: prefer selected model until runtime refresh
* gateway: simplify session model identity selection
* gateway: avoid transcript model fallback on cost-only reads
