Module attachments 

Community message attachments (NIP-92 imeta).

Unlike NIP-17 DMs (one media item per event), a Community message event carries its caption in content plus one imeta tag per attachment — so a single message can mix text and N files. Each imeta holds the per-file AES-GCM key+nonce (the NIP-17 attachment technique: fresh random key per file), so the Blossom ciphertext is only decryptable by members who can open the event.

Functions

attachment_from_imeta

Parse a single imeta tag into an Attachment. None if the tag isn’t an imeta or is missing the required url / decryption fields. download_dir computes the (not-yet-downloaded) local target path, mirroring the DM file-attachment path.

attachment_to_imeta

Encode an Attachment as a NIP-92 imeta tag with Vector’s encryption fields. Entries are space-delimited key value strings (NIP-92 form); a value may contain spaces (e.g. a filename) since only the first space delimits key from value.

attachments_from_tags

Parse every imeta tag on an event into attachments, order preserved. Capped: a max-size event can carry ~1700 imeta tags, each becoming a persisted + in-STATE Attachment — bound the per-message amplification.

strip_attachment_urls

Strip attachment blob URLs that some clients (e.g. Armada) inline into the message content IN ADDITION to the imeta tag. Vector renders the file from the imeta, so the inline copy is pure redundancy: it wastes storage and makes the frontend try to web-preview a raw (often encrypted) blob URL — which can’t decode, so it just errors. Display-only: the wire event and message id are untouched (we never re-sign), so this can’t affect dedup or authority.