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Get a media-library upload session

GET
/v1/asset-upload-sessions/{upload_id}
const upload = await bird.assets.uploads.get("aus_01krdgeqcxet5s7t44vh8rt9mg");
console.log(upload.state);
Response200
{
  "id": "aus_01krdgeqcxet5s7t44vh8rt9mg",
  "state": "pending",
  "folder_id": "asf_01krdgeqcxet5s7t44vh8rt9mg",
  "file": {
    "filename": "invoice.pdf",
    "content_type": "application/pdf",
    "size_bytes": 1024,
    "sha256": "4e2090a479f7ce6b17ad31f991988f12571bcafbd4a441cc4063644fc1400ae0"
  },
  "result": {
    "asset_id": "ast_01krdgeqcxet5s7t44vh8rt9mg"
  },
  "next": [
    {
      "kind": "operation"
    }
  ],
  "asset": {
    "id": "ast_01krdgeqcxet5s7t44vh8rt9mg",
    "url": "https://us1.assets.birdusercontent.com/6fcy8y6a483sewgnjk2g35y2qz/01krdgeqcxet5s7t44vh8rt9mg/document.pdf",
    "thumbnail_url": null,
    "name": "document.pdf",
    "content_type": "application/pdf",
    "kind": "document",
    "size_bytes": 48210,
    "width": null,
    "height": null,
    "alt_text": null,
    "folder_id": null,
    "deleted_at": null,
    "created_at": "2026-05-20T09:14:52Z",
    "updated_at": "2026-05-20T09:14:52Z"
  }
}

Returns the upload session and its saved publication receipt. Requires current asset write access and the connection that created the session. Status checks do not issue another upload capability.

Parameters

upload_idstring

ID of the media-library upload session.

Response Payload

id
string
required
state
string
required

Upload progress. Pending accepts a transfer; finalizing is checking and publishing it. Completed has a saved result. Rejected, cancelled and expired allow no new upload instruction or publication. An already issued upload URL can remain usable until its expiry.

Possible values: pending, finalizing, completed, rejected, cancelled, expired

expires_at
string
required

Absolute session expiry. Completion must finish before this deadline; starting it or refreshing an upload instruction does not extend it.

name
string
required

Frozen display name for a newly published asset.

alt_text
nullable string
required

Frozen alternative text, or null when omitted.

folder_id
nullable string
required

Frozen destination folder, or null for the library root.

file
object
required

Exact properties of the original file. Calculate size and SHA-256 from its bytes before creating a session. Images allow up to 5,242,880 bytes; other supported media allow up to 25,000,000 bytes.

Show child attributes
result
nullable object
required

Saved publication receipt, or null until completed.

Show child attributes
last_error
nullable object
required

Last completion error, or null when no failure is recorded.

Show child attributes
next
array of object
required

Available next steps for this session.

Show child attributes
asset
nullable object
required

Canonical asset when available, or null before completion or when unavailable.

Show child attributes
asset.created_at
string
required
asset.updated_at
string
required
asset.id
string
required
asset.url
string
required

The asset's permanent public URL. Safe to embed or link in sent messages; for a document the usable form is a link.

asset.thumbnail_url
nullable string
required

A small preview of the asset, for rendering a picker or a grid. Intended for your own interfaces rather than for embedding in messages. Null for every kind but image: generating a preview of a video, an audio file, or a document would mean rendering its contents, which the library does not do. Show an icon for the kind instead.

asset.name
string
required

The asset's display name. Defaults to the uploaded file's name.

asset.content_type
string
required

The stored file's media type, determined from its contents.

asset.kind
string
required

The category a media-library asset's type falls into. Use it to group or filter a mixed library.

  • image: covers PNG, JPEG, and GIF.
  • video: covers MP4, WebM, and QuickTime.
  • audio: covers MP3, M4A, Ogg, and WAV.
  • document: covers PDF.

Possible values (may grow over time): image, video, audio, document

asset.size_bytes
integer
required

The stored file's size in bytes. Images are re-encoded on upload, so for those this can differ from the size of the file you sent. Every other kind is stored byte-for-byte.

asset.width
nullable integer
required

The stored image's width in pixels. Null for every kind but image.

asset.height
nullable integer
required

The stored image's height in pixels. Null for every kind but image.

asset.alt_text
nullable string
required

Default alternative text for the asset. Use it as the starting point for an image description when inserting the asset into content. Updating this field does not update descriptions already copied into saved content.

asset.folder_id
nullable string
required

The folder the asset is filed in, or null when it sits at the top level of the library. Filing an asset never changes its URL.

asset.deleted_at
nullable string
required

When the asset was removed from the library, or null if it is still listed. A removed asset keeps serving at its original URL.

Related resources

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