feat: let agents work with PDFs, ZIPs, and other files

[t3dotgg]

T3 Code only accepted image attachments. PDFs, ZIP archives, and large text files had no direct route to an agent.

Web, desktop, and mobile can now upload files up to 50 MB directly to their environment. Agents receive the saved file path, images keep their existing behavior, and mobile supports the system file picker and share sheet.

Uploads stream to disk, pending files reuse hard links, and downloaded documents cannot run as pages.

The mobile share-sheet change requires a new iOS and Android store build before later OTA updates work.

Built with GPT-5.6 Sol in the Codex harness.

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Note

High Risk
Touches signed upload tokens, streamed attachment storage, asset download headers, and mobile share-sheet MIME handling—security-sensitive file ingest and serving paths.

Overview
Agents can now receive generic files (PDFs, ZIPs, etc.), not just images. Servers advertise a fileAttachments capability with a 50 MB upload cap; images keep the existing 10 MB path.

Web and mobile composers pick, persist, and upload files alongside images. Mobile copies files into app-owned storage, cleans them when drafts/outbox no longer reference them, and accepts files from the share sheet (*/* on Android; iOS file share counts). File picking is gated on the server capability.

Uploads stream to disk instead of buffering the whole body. Attachment IDs can encode a safe extension so files resolve without directory scans. Pending uploads are claimed with a hard link (copy fallback). Document downloads force Content-Disposition: attachment and a sandbox CSP so they cannot execute as pages.

Providers still get images as attachments; files are injected as on-disk path lines in the turn text. Legacy image upload tokens remain valid. Mobile share-sheet MIME changes need a new store build before later OTAs.

^{Reviewed by Cursor Bugbot for commit d014010. Bugbot is set up for automated code reviews on this repo. Configure here.}

Note

Add support for non-image file attachments (PDFs, ZIPs) across web, mobile, and server

• Introduces a ChatFileAttachment type and fileAttachments environment capability (50 MB max) in packages/contracts/src/orchestration.ts, expanding ChatAttachment beyond images
• Web composer (apps/web/src/components/chat/ChatComposer.tsx) supports attaching, uploading, retrying, and removing generic files; drafts and prompt stash persist file references without file bytes
• Mobile composer and sharing pipeline (apps/mobile/src/lib/composerImages.ts, apps/mobile/src/features/sharing/incoming-share-model.ts) can pick, persist, upload, and clean up generic files via expo-file-system
• Server (apps/server/src/assets/AttachmentUpload.ts, apps/server/src/attachmentStore.ts) issues typed upload URLs, streams file bodies to disk preserving file extensions, enforces signed byte limits, and serves file assets with Content-Disposition: attachment headers
• Providers (apps/server/src/provider/Layers/ProviderService.ts) receive only image attachments in the routed input array; file attachments are referenced via path hints in the input text rather than forwarded as image content
• Risk: AttachmentUploadClaims schema adds a type field defaulting to 'image' for legacy tokens — verify all existing upload token decoders handle the new field; attachmentIdExtensionSuffix appends -bin for invalid/missing extensions, so attachment IDs now have a different shape than before

^{Macroscope summarized d014010.}

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[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	13.4 KiB	13.4 KiB	+1 B (+0.0%)	15.1 KiB	✅
Codex	Thread snapshot wire	6.9 KiB	6.9 KiB	0 B (0.0%)	7.3 KiB	✅
Codex	Live turn WebSocket wire	6.5 KiB	6.5 KiB	+1 B (+0.0%)	7.8 KiB	✅
Codex	Live turn WebSocket decoded	55.0 KiB	55.0 KiB	0 B (0.0%)	66.4 KiB	✅
Codex	Live turn messages	16	16	0 (0.0%)	21	✅
Claude	Total thread wire	13.5 KiB	13.5 KiB	+6 B (+0.0%)	15.1 KiB	✅
Claude	Thread snapshot wire	6.9 KiB	6.9 KiB	+1 B (+0.0%)	7.3 KiB	✅
Claude	Live turn WebSocket wire	6.6 KiB	6.6 KiB	+5 B (+0.1%)	7.8 KiB	✅
Claude	Live turn WebSocket decoded	55.8 KiB	55.8 KiB	0 B (0.0%)	66.4 KiB	✅
Claude	Live turn messages	16	16	0 (0.0%)	21	✅

Baseline: f035a0f · PR result: d014010 · Source CI: success

Scenario and decoded snapshot size

10 historical turns, 5 command tools per turn, 878.9 KiB retained MCP result per historical turn, and a 1.05 MiB retained result in the measured turn.

• Codex decoded thread snapshot: 109.4 KiB
• Claude decoded thread snapshot: 110.1 KiB

Updated in place by a trusted workflow. PR artifacts are strictly validated and never executed.

[macroscopeapp]

Approvability

Verdict: Not approved

Macroscope's review found this PR not approvable — This change introduces end-to-end file attachments across web and mobile, including new upload protocols, server-side storage and download handling, provider path integration, draft persistence, and cleanup workflows. Its cross-platform scope and substantial runtime/storage side effects require human review.

^{You can add or adjust custom eligibility rules. Learn more.}

[macroscopeapp]

One UI consistency finding in the new web composer file attachment row. Everything else in the changed web scope (the paperclip Button size="icon-sm" + Tooltip/TooltipTrigger render composition, the icon-xs retry/remove actions, the timeline download anchor, and the semantic color tokens used) matches the existing composer/timeline conventions.

^{Posted via Macroscope — UI Consistency}

[macroscopeapp]

One finding in the changed web UI: the new attachment download link inside the user message bubble hovers to text-primary, which is the solid-control fill role rather than a foreground role owned by the message surface. Details inline. (The unbounded retry tooltip in ChatComposer.tsx file rows from the earlier review is still open; not re-posting it.)

^{Posted via Macroscope — UI Consistency}

[cursor]

Cursor Bugbot has reviewed your changes using high effort and found 3 potential issues.

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^{Reviewed by Cursor Bugbot for commit ae250e2. Configure here.}

[macroscopeapp]

One new finding in scope, plus one carried-over finding that is still unresolved.

New: the stashed-file count badge in ComposerStashMenu does not pin a type scale or an icon tone, so it renders larger than every sibling metadata span in the row and its icon is re-colored by the CommandItem primitive. Inline comment below.

Still open from a previous run (not re-posted): apps/web/src/components/chat/MessagesTimeline.tsx:1075 — the file download link on the user message bubble takes its hover color from --primary, which index.css defines as the solid-control fill role rather than a text role owned by the bg-message surface, so the hover state is not guaranteed to stay legible in themed palettes. A message-surface-owned foreground (e.g. the existing text-message-foreground with an opacity/underline hover) keeps the hover state under the surface that renders it.

Everything else in the changed web UI looks consistent: the new composer attach control uses Button variant="ghost" size="icon-sm" inside the standard Tooltip/TooltipTrigger render composition, the failed-upload tooltip now matches the image tile's max-w-64 whitespace-normal leading-tight cap, and the attach affordance is correctly gated out of the collapsed-mobile and approval footers.

^{Posted via Macroscope — UI Consistency}

[macroscopeapp]

UI consistency review of the changed web files. Two findings, both about draft/stash surfaces that summarize composer attachments and were not updated for the new files list. The previously flagged message-link hover token and the uncapped retry tooltip in ChatComposer are both resolved in this revision.

^{Posted via Macroscope — UI Consistency}

[baptisteArno]

YES