fix(server): pass Codex image attachments by path to avoid oversized requests

[saphid]

What Changed

Codex now receives image attachments as local file paths (localImage) instead of inline base64 data URLs, so the turn/start request no longer scales with image file size. The 951 KB PNG from the reproduction thread no longer produces an oversized provider request.

Other providers, the wire contracts, and all client surfaces are unchanged. Claude, Cursor, Grok, and OpenCode already send attachments without inlining files into requests.

Why

Continuing an attachment-heavy Codex thread with a large image could produce unexpected status 413 Payload Too Large from http://127.0.0.1:8317/v1/responses: the adapter base64-inlined the full PNG into the serialized request, pushing the provider payload over the limit.

This change prevents new oversized image rollouts. It does not add automatic compaction or recovery for provider histories that are already oversized.

Verification

• pnpm exec vp test run apps/server/src/provider/Layers/CodexAdapter.test.ts apps/server/src/provider/Layers/CodexSessionRuntime.test.ts: 93 passed, 0 failed.
• pnpm run typecheck in apps/server: exit 0. The command also emits repository-wide Effect suggestions.
• No UI changes; no screenshots or video apply.

Checklist

• This PR is small and focused
• I explained what changed and why
• I included before/after screenshots for any UI changes

Implementation used GLM-5.3 Flash through AI Enablers in T3 Code.

Summary by CodeRabbit

• Improvements

  • Image attachments are now passed to the Codex runtime using local file paths, improving handling of larger images and avoiding unnecessary file-content loading.
  • Image attachment processing now uses local files consistently throughout Codex sessions.

• Behavior Changes

  • Requests that exceed the initial turn-start limit are no longer automatically retried after thread compaction.

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[macroscopeapp]

Approvability

Verdict: Approved at e8eca22

Macroscope's review found this PR approvable — This is a narrowly scoped Codex bug fix that replaces base64 image payloads with validated local paths, preventing request growth while preserving existing attachment behavior. The protocol already supports local images, and focused tests cover the adapter and runtime serialization.

Notes:

• No code objects were reviewed. Approvability was decided on eligibility alone.

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• apps/server/src/provider/Layers/CodexSessionRuntime.ts

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📝 Walkthrough

Walkthrough

The Codex provider now passes image attachments by local filesystem path instead of base64 data URLs. Runtime attachment types and fixtures use localImage with a path field. The adapter test verifies the resolved path.

Changes

Codex provider updates

Layer / File(s)	Summary
Local image attachment contract apps/server/src/provider/Layers/CodexSessionRuntime.ts, apps/server/src/provider/Layers/CodexSessionRuntime.test.ts	Runtime attachment inputs and turn-start parameters now use localImage attachments with filesystem paths. Tests use and expect the new attachment shape.
Adapter local path flow apps/server/src/provider/Layers/CodexAdapter.ts, apps/server/src/provider/Layers/CodexAdapter.test.ts	The adapter returns resolved image paths without reading file contents or acquiring the filesystem service. The test verifies that the runtime receives the resolved path.

Priority: ➖ Normal

Estimated code review effort: 2 (Simple) | ~12 minutes

Suggested reviewers: t3dotgg, juliusmarminge

Merge Risk: ⚪ Minimal · up to e8eca

Codex image attachments now pass resolved local paths through the adapter and runtime contract, avoiding request-size inflation. The removed 413 retry flow no longer risks retrying before compaction completes.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 6 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly and concisely describes the main change: passing Codex image attachments by filesystem path to avoid oversized requests.
Description check	✅ Passed	The description includes the required change and rationale sections, provides verification results, explains that there are no UI changes, and includes the checklist. It is focused and sufficiently co…

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Actionable comments posted: 1

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Inline comments:
In `@apps/server/src/provider/Layers/CodexSessionRuntime.ts`:
- Line 2377: Update the retry flow around client.raw.request("turn/start",
params) to wait for the matching item/completed notification for the
contextCompaction item after initiating manual compaction, and propagate any
compaction failure before retrying. Preserve the existing turn/start request
only after successful compaction completion.

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ℹ️ Review info

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📥 Commits

Reviewing files that changed from the base of the PR and between d29c56a and 58906da.

📒 Files selected for processing (6)

• apps/server/src/provider/Layers/CodexAdapter.test.ts
• apps/server/src/provider/Layers/CodexAdapter.ts
• apps/server/src/provider/Layers/CodexCollabRuntime.integration.test.ts
• apps/server/src/provider/Layers/CodexSessionRuntime.test.ts
• apps/server/src/provider/Layers/CodexSessionRuntime.ts
• apps/server/src/provider/testFixtures/codexCollabMockPeer.mjs

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