Cloud Files — Skill

This skill enforces the architecture established in features/files/FEATURE.md. Read it first. This skill is the checklist version.

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Non-negotiables

• Reads: supabase-js (RLS) + RPC cloud_get_user_file_tree. No REST calls for reads unless the endpoint returns bytes.
• Metadata writes: direct authenticated database calls through the canonical RPCs.
• File bytes, signing, and processing: the Files service. Always send the caller JWT and request id.
• Never call an object-store SDK from the client. Use the public surface in features/files/index.ts.
• All file state in the cloudFiles Redux slice. No local useState for file data. No new Redux slices for files — extend the existing one.
• All types in features/files/types.ts. Do not declare inline types or per-file type files. Import via features/files/index.ts.
• Identity is fileId. Never cache by file_path — paths move with renames.
• Mutations are optimistic + rollback (pattern from features/agents/redux/agent-shortcuts/thunks.ts). No spinner-then-refetch.
• Realtime is the source of truth for cross-session sync. The middleware dedups echoes of local writes via the request ledger — always register a requestId on every mutation.
• Mobile rules: Drawer not Dialog; push-nav not tabs; dvh not vh; pb-safe on fixed bottoms; 16px inputs.
• FieldFlags<K> not Set<K> in Redux state (JSON-serializability).
• app/(core)/files/ routes follow app/(core)/_read_first_route_rules/RULES.md. SSR-first, zero layout shift; 'use cache' is NOT available (cacheComponents off — see CLAUDE.md).

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Before writing code

Read, in this order:

1. /Users/armanisadeghi/code/common-docs/systems/files/file-service/WIRE_CONTRACT.md — the backend contract (routes, shapes, quotas, TUS, share tokens).
2. features/files/FEATURE.md — current FE architecture.
3. features/agents/redux/agent-shortcuts/slice.ts — the record + dirty-tracking pattern you're copying.

For route work under app/(core)/files/, additionally run these skills before writing code:

• .claude/skills/ssr-zero-layout-shift/SKILL.md
• .claude/skills/ios-mobile-first/SKILL.md (for any mobile branch)

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Common tasks

Upload files

import { useAppDispatch } from '@/lib/redux/hooks';
import { uploadFiles } from '@/features/files/redux/thunks';

const dispatch = useAppDispatch();
await dispatch(
  uploadFiles({ files: [file], parentFolderId, visibility: 'private' })
).unwrap();

Render a file as <img> / <video>

import { useMediaResolution } from "@ai-matrx/media/core";

// Prefer <InlineMediaRef ref={{ file_id }} /> from @ai-matrx/media/react.
const src = useMediaResolution(fileId).resolution?.src ?? null;
return <img src={src ?? undefined} />;

Pick a file for "attach"

import { openFilePicker } from '@/features/files/components/pickers/FilePicker';

const [file] = await openFilePicker({ multi: false });

List contents of a folder

import { useFolderContents } from '@/features/files/hooks/useFolderContents';

const { files, folders, loading } = useFolderContents(folderId);

Create a share link

import { useSharing } from '@/features/files/hooks/useSharing';

const { createShareLink } = useSharing();
const link = await createShareLink(fileId, {
  permission_level: 'read',
  expires_at: '2026-12-31T23:59:59Z',
  max_uses: 50,
});
// link.share_token → https://app.aidream.com/share/${link.share_token}

---

Forbidden

• Direct object-store SDK calls.
• New Redux slices for files. Extend cloudFiles.
• Local types declarations for CloudFile, CloudFolder, etc. Import from features/files/index.ts.
• window.alert / confirm / prompt. Use components/ui/alert-dialog.
• Dialog on mobile. Branch via useIsMobile() to Drawer.
• h-screen / vh under app/(core)/files/ — use dvh, --header-height, pb-safe.
• Hardcoded paths. Use features/files/utils/path.ts.
• Set in Redux state. Use FieldFlags<K> from @ai-matrx/agents/field-flags.
• Directly importing core components from components/core/FileTree/internal/*. Consume from the barrel.
• Calling the REST API without a requestId. The realtime middleware will not be able to dedup, and you will see visual flicker.

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When something breaks

Symptom	Likely cause
Optimistic update flickers/reverts after a second	Missing requestId on the REST write. Realtime echo is overwriting state.
Uploads succeed but don't appear in tree	Realtime middleware not attached. Check <CloudFilesRealtimeProvider> is mounted under the user-scoped layout.
Signed URL returns 403	Expired. Use useFileSrc (the handler's expiry-wheel auto-refreshes). Never cache raw signed URLs across mounts.
Tree shows stale state after reconnect	reconcileTree() dispatch missing from the realtime middleware's SUBSCRIBED-after-error handler.
Type error on CloudFile.metadata	You're using an inline type somewhere. Delete it and import from types.ts.
413 on upload	File >tier cap (or >100MB free). For >100MB uploads, use the TUS endpoint at /files/upload/tus (transport is chosen in upload/cloudUpload.ts).

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Change-log expectations

After any non-trivial change:

1. Update FEATURE.md — architecture sections, invariants, status.
2. Append to the bottom of FEATURE.md change log with date + one-line summary.
3. If you need something new from the file service, add it to /Users/armanisadeghi/code/common-docs/systems/files/file-service/HANDOFF.md.

Treat docs as weight-equal to code. Stale docs cascade across every future agent touching this system.