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POST
Register Upload

Authorizations

Authorization
string
header
required

API key from Settings > Developer > REST API

Headers

Moda-Version
enum<string>
default:2026-05-01

Calendar-dated API version pin. New integrations should pin 2026-05-01 to opt into the newest response shapes. For back-compat the server also accepts requests with no header and resolves them to the current default (today: 2026-04-12); that default advances on each sunset date. Any unsupported value returns 400 unsupported_version.

Available options:
2026-04-12,
2026-05-01
Example:

"2026-05-01"

Body

application/json
storage_key
string
required

storage_key returned by a prior POST /v1/uploads/url after the PUT completed.

filename
string | null

Filename to record on the File row. Defaults to the basename embedded in storage_key.

Maximum string length: 512
mime_type
string | null

MIME type to record on the File row. Defaults to the type the signed URL was originally bound to (inferred from the filename when not supplied).

folder_id
string | null

Prefixed fld_ wire ID (Crockford base32 body) — the canonical, recommended form. For back-compat, a bare UUID string is also accepted in both path parameters and JSON request bodies (older integrations that stored raw UUIDs keep working). Both are permanent, supported inputs.

Pattern: ^fld_[0-9A-HJKMNP-TV-Za-hjkmnp-tv-z]{26}$
Example:

"fld_01HT9WK8N3M2J4A5Z6P7Q8R9TV"

Response

Successful Response

id
string
required

Unique file identifier (prefixed file_...).

Pattern: ^file_[0-9A-HJKMNP-TV-Za-hjkmnp-tv-z]{26}$
Example:

"file_01HT9WK8N3M2J4A5Z6P7Q8R9TV"

url
string
required

Stable proxy URL for the uploaded file. Use this in attachment URLs.

filename
string
required

Filename of the uploaded file.

mime_type
string
required

MIME type of the file.

size_bytes
integer | null

File size in bytes.

was_duplicate
boolean
default:false

True if an identical file already existed (deduplicated).

folder_id
string | null

Prefixed fld_ wire ID (Crockford base32 body) — the canonical, recommended form. For back-compat, a bare UUID string is also accepted in both path parameters and JSON request bodies (older integrations that stored raw UUIDs keep working). Both are permanent, supported inputs.

Pattern: ^fld_[0-9A-HJKMNP-TV-Za-hjkmnp-tv-z]{26}$
Example:

"fld_01HT9WK8N3M2J4A5Z6P7Q8R9TV"