Old behaviour: HEIC/AVIF photos, .mov / .webm / .mkv videos, and niche
audio (FLAC, etc.) got rejected outright at upload with "Images are
not supported" / "Videos are not supported" errors. Strict but
unfriendly — recipients could still receive these as a downloadable
file via WhatsApp's document path; we just weren't using it.
New behaviour: anything not playable inline gets routed through the
document path automatically. The recipient downloads the file and
opens it in their default app. The 100 MB document cap applies
instead of the inline 5 / 16 / 16 MB caps. Only oversized uploads
get rejected.
Where the policy lives
----------------------
The classifier moved into a new `@cmbot/shared/whatsapp-media`
module so the web upload validator AND the bot's fire-reminder send
path share one source of truth:
- resolveDeliveryKind(mime, bytes?) → "image" | "video" | "audio"
| "document". Native types stay as-is; HEIF / AVIF / QuickTime /
WebM / Matroska / non-MP3-or-M4A audio all collapse to "document".
- Bytes argument is optional but recommended — sniffing the first
12 bytes of the file catches iOS Safari's habit of labelling
a HEIC as image/jpeg or a .mov as video/mp4. Bytes win when they
disagree with the mime.
Web side
--------
- `lib/whatsapp-media.ts` re-exports the shared helpers and keeps
only the validator + byte-formatter. `validateForWhatsApp` calls
resolveDeliveryKind internally; the size cap it returns is for the
RESOLVED kind (so a HEIC routes to document and gets the 100 MB
cap). The "Images are not supported" / "Videos are not supported"
rejection messages are gone — there's no format rejection anymore.
- `actions/media.ts` collapses the previous explicit-mime + byte-sniff
pair into a single `validateForWhatsApp(mime, size, bytes)` call.
- Compose-step upload-zone hint updated to spell out the per-kind
caps: "JPEG/PNG up to 5 MB · MP4/3GP up to 16 MB · MP3/M4A/OGG
up to 16 MB · documents up to 100 MB".
Bot side
--------
- `fire-reminder.ts` reads the first 12 bytes of the file before
dispatching and calls `resolveDeliveryKind(mimeType, head)` to
pick the senderKind. So a HEIC on disk (whose mime claims
image/jpeg) gets sent via Baileys' document path — no failed
thumbnail extraction, message arrives as a downloadable .heic.
- New `readHeadBytes(filePath, n)` helper opens, reads N bytes,
closes — no full-file slurp.
Tests
-----
249 web + 31 shared + 26 bot = 306 passing total.
Web (`lib/whatsapp-media.test.ts`):
- "HEIC at 30 MB allowed: routes to document (100 MB cap)"
- "HEIC at 110 MB rejects: exceeds the document cap"
- "MOV at 50 MB allowed (would be 16 MB cap as video, 100 MB as
document)"
- "MOV pretending to be mp4 demotes to document (50 MB allowed)"
- "FLAC audio routes to document path"
- "genuine MP4 byte-sniff path keeps it as video"
Shared (`packages/shared/src/whatsapp-media.test.ts`, new):
- The cross-package contract: 11 tests covering size limits,
classifyMediaKind, resolveDeliveryKind for native + demoted +
byte-sniff cases, plus the underlying helpers.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Symptom
-------
The upload action rejected anything over 50 MB with a flat
"File too large (>50MB)" — a number that was both too generous for
images (WA caps at 5 MB) and too restrictive for documents (WA
allows 100 MB). And anything over 1 MB was being rejected even
earlier by Next's default Server Action body limit, with a much
less actionable error.
Fix
---
1. New `lib/whatsapp-media.ts` resolves an uploaded file's MIME type
to a WhatsApp delivery kind and validates it against the
per-kind cap that WA actually enforces:
image → 5 MB image/* except sticker-mode
video → 16 MB video/*
audio → 16 MB audio/*
document → 100 MB anything else (PDFs, office docs, …)
Anything not recognised as image/video/audio falls through to
"document", which is also the Baileys sender path the bot uses
to deliver it. So a .zip or .csv ends up correctly classified
AND correctly limited to the document cap.
Error messages now name the kind and show both the actual size
and the cap: "Image too large (5.2 MB > 5.0 MB limit on
WhatsApp)".
2. `next.config.ts` lifts the Server Action body limit from the 1 MB
default to 100 MB, so document uploads actually reach the action
instead of getting bounced at the framework boundary. The WA
per-kind validator inside the action enforces the real limit
from there.
3. The compose-step upload zone hint now reflects the per-kind caps
("Image up to 5 MB · video / audio up to 16 MB · document up to
100 MB") instead of the wrong flat "up to 50 MB" value.
Tests (17 new cases, total 189)
-------------------------------
- classifyMediaKind: image/video/audio prefix routing, fall-through
to document for unknown / empty / octet-stream / text/plain.
- validateForWhatsApp: at-cap, just-under-cap, just-over-cap for
image (5 MB) / video (16 MB) / audio (16 MB) / document (100 MB);
zero-byte rejected; unknown-mime 60 MB upload accepted as document.
- WA_MAX_BYTES sanity: equals the document cap and is >= every other
per-kind limit (so it's safe to use as the framework body cap).
- formatBytes: bytes / KB (no decimals) / MB (one decimal) rendering.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Reminders can now deliver a stack of message parts in send order. The
DB and bot's fire-reminder loop already supported this — only the UI
and the server action's input shape were single-message. This change
makes the whole flow stack-aware end-to-end.
What's new
----------
A reminder is now a list of MessagePart objects:
{ kind: "text", textContent: "Hi", mediaId: null }
{ kind: "media", textContent: "cap", mediaId: uuid }
{ kind: "media", textContent: null, mediaId: uuid }
The bot fires them in order with ~1.5 s spacing (already the case in
fire-reminder.ts).
Cap of 10 parts per reminder. Anything more clutters the URL beyond
the 2KB practical budget for the wizard's encoded `messages=…` param.
Where this shows up
-------------------
1. `<MessageStack>` — new shared component (apps/web/src/components/
message-stack.tsx). Each block is either a text Textarea or a
media block (file picker + preview + caption Input). Per-block
move-up / move-down / delete buttons. "+ Add text" / "+ Add file"
buttons at the bottom. Reused by both the wizard's compose step
AND the per-section Edit Message page.
2. Edit Message page — was a single Textarea + read-only attachment
indicator with a "Replacing it isn't supported" note. Now uses
MessageStack and lets the operator add/remove/reorder parts AND
swap the file on a media block, fixing
the asked-for "should let user change media files too" gap.
3. Wizard — Compose / When / Groups / Review pass a single
`messages=<urlencoded JSON>` param instead of three separate
text/mediaId/caption fields. The Review step renders one row per
part, with file names resolved from the DB so users see "menu.pdf"
not an opaque uuid. Every step accepts the legacy fields too and
folds them into the new shape on entry, so older bookmarked URLs
keep working.
4. Server actions (createReminder / updateReminder) accept either:
- The new `messages: MessagePart[]` field, OR
- The legacy `text` / `mediaId` / `caption` triple,
and resolve to a flat parts list before doing anything else. Both
actions then write one row per part into `reminder_messages` with
a sequential `position` column, replacing the old "always 1 row"
logic in updateReminderAction.
5. The reminder name (visible in lists, detail header, etc.) is
sourced from the first part with a non-empty text body — falling
back to the literal "Reminder" if every part is media-without-
caption. Capped at 50 chars to fit the existing column.
Wire-format helpers
-------------------
New `lib/reminder-messages.ts`:
- `MessagePart` interface (the canonical shape)
- `isValidMessagePart` — reject empty texts and orphan-mediaId rows
- `encodeMessages` / `decodeMessages` — URI-encoded JSON, drops
invalid entries, returns null when nothing valid is left
- `legacyMessageToParts` — synthesise a one-element stack from the
old text/mediaId/caption fields (used by step pages on entry)
Tests (15 + 5 = 20 new; 146 total, was 132 + adjustment)
--------------------------------------------------------
- `lib/reminder-messages.test.ts`: round-trip a non-trivial stack;
survive URL-unsafe characters in text (\\n, & = % #); reject
null / empty / garbage; drop invalid entries; legacy-fallback paths.
- `edit-message-form.test.tsx`: rewrites for the new prop shape
(initialMessages instead of initialText/initialMediaId/initialCaption);
asserts the form renders one block per initial part and that media
filename appears in the SSR markup.
- `no-render-warnings.test.tsx`: same prop-shape update for the two
EditMessageForm hydration / button-nesting guards.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
