agency-board
POST /v1/agency/boards/{boardId}/cards/{cardId}/attachments
Attach a file to a card.
Authentication
Send an API key as a bearer token. The endpoint checks agency.board.manage; a key without it is refused with 403, not 404.
This endpoint takes no organisation id. Your key already identifies the organisation it belongs to, and the response is scoped to it.
Try it
Replace anything in angle brackets with your own values, and the key placeholder with a key from your dashboard.
curl -X POST https://api.zinndigital.com/v1/agency/boards/{boardId}/cards/{cardId}/attachments \
-H "Authorization: Bearer zdk_live_…"Signed in? The API console in your dashboard fills in your real organisation id and your own key, and runs the request against the live API so you can see the actual response. Open this endpoint in the API console
Details
⚖️ 25 MB per file and 2 GB per organisation, owner-ruled 2026-09-03. The organisation quota is counted across every board it owns, because a per-board cap is escaped by making another board. ⛔⛔ A stored file is pending and not downloadable by anybody, including the agency's own staff, until a malware scan has passed it. A client's upload is the best phishing route into an agency there is, and the person opening it has production access to that client's sites. pending, infected and error all refuse — an unscannable file is not a clean file. Accepted types are PNG, JPEG, GIF, WebP, PDF, plain text and CSV, each validated by its magic bytes rather than by the declared content type. No archives (a way to smuggle every format not on the list), no Office documents (macros), no SVG (a script container browsers execute).
Parameters
| Name | Type | Required | What it is |
|---|---|---|---|
boardId (path) | Uuid | Yes | Project board ID (UUIDv7). |
cardId (path) | Uuid | Yes | Board card ID (UUIDv7). |
Response
| Name | Type | Required | What it is |
|---|---|---|---|
id | Uuid | Yes | UUIDv7 identifier — sortable by creation time (docs/02 §8). |
card_id | Uuid | Yes | UUIDv7 identifier — sortable by creation time (docs/02 §8). |
filename | string | Yes | — |
content_type | string | No | — |
size_bytes | integer | Yes | — |
visibility | AgencyBoardVisibility | No | Who may see this object. internal is always the default. A card reaches the client only when it is client and its column is too — an AND, not inheritance, because that… |
scan_state | AgencyBoardAttachmentScanState | Yes | Where an uploaded file is in the malware pipeline. ⛔ clean is the ONLY state the bytes are ever served in — pending, infected and error all refuse, including to the… |
downloadable | boolean | Yes | ⭐ Whether these bytes may be fetched right now. Computed from the scan state by the engine rather than derived by a caller — two copies of "may this leave the building" is how the… |
uploaded_by | AgencyBoardActor | No | — |
created_at | string | No | — |
Errors this endpoint can return
401 · 403 · 404 · 422