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Open a browser fallback for a media upload

POST
/v1/asset-upload-sessions/{upload_id}/browser
const handoff = await bird.assets.uploads.handoff(
  "aus_01krdgeqcxet5s7t44vh8rt9mg",
);
if (handoff.browser_url) console.log(handoff.browser_url);
Response200
{
  "session": {
    "id": "aus_01krdgeqcxet5s7t44vh8rt9mg",
    "state": "pending",
    "expires_at": "2026-11-04T23:00:00Z",
    "name": "Invoice",
    "alt_text": null,
    "folder_id": null,
    "file": {
      "filename": "invoice.pdf",
      "content_type": "application/pdf",
      "size_bytes": 1024,
      "sha256": "4e2090a479f7ce6b17ad31f991988f12571bcafbd4a441cc4063644fc1400ae0"
    },
    "result": null,
    "last_error": null,
    "next": [],
    "asset": null
  },
  "browser_url": "https://bird.com/dashboard/w/ws_01krdgeqcxet5s7t44vh8rt9mg/media-library/uploads/aus_01krdgeqcxet5s7t44vh8rt9mg",
  "next": [
    {
      "kind": "external",
      "description": "Open browser_url and have a person with asset write access select the original file and publish it. Their browser must reach the storage hostname. Opening the page does not complete the upload."
    },
    {
      "kind": "operation",
      "operation": "getAssetUploadSession",
      "params": {
        "upload_id": "aus_01krdgeqcxet5s7t44vh8rt9mg"
      },
      "description": "After the person finishes, read the saved result using the original workspace and connection."
    }
  ]
}

Offers an existing upload session to a signed-in person with asset write access in its workspace. Only the same OAuth connection or API key that created the session can request this fallback. The file, metadata, capacity reservation and one-hour deadline stay unchanged. Repeating the request returns the same page for a pending session. A non-pending session returns its current state without a browser URL. Enabling the handoff allows any currently authorized person in that workspace to complete or cancel it, independently of the original connection's continued access. The person must select matching file bytes; opening the page never publishes them.

Parameters

upload_idstring

ID of the media-library upload session.

Response Payload

session
object
required

The original upload session and any saved publication receipt. In this response, session.next is empty; follow the top-level next steps.

Show child attributes
session.id
string
required
session.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

session.expires_at
string
required

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

session.name
string
required

Frozen display name for a newly published asset.

session.alt_text
nullable string
required

Frozen alternative text, or null when omitted.

session.folder_id
nullable string
required

Frozen destination folder, or null for the library root.

session.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
session.file.filename
string
required

Original filename, including its extension.

session.file.content_type
string
required

Media type of the original file. Supported values are image/png, image/jpeg, image/gif, video/mp4, video/webm, video/quicktime, audio/mpeg, audio/mp4, audio/ogg, audio/wav, and application/pdf.

Supply the exact value without parameters. Unsupported values return E20001. Completion checks this against the file's contents.

session.file.size_bytes
integer
required

Exact size of the original file in bytes.

session.file.sha256
string
required

SHA-256 of the original bytes, encoded as lowercase hexadecimal.

session.result
nullable object
required

Saved publication receipt, or null until completed.

Show child attributes
session.last_error
nullable object
required

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

Show child attributes
session.next
array of object
required

Available next steps for this session.

Show child attributes
session.asset
nullable object
required

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

Show child attributes
browser_url
nullable string
required

Bird page for a pending session, or null when it no longer accepts an upload. The link grants no access; the person must sign in and have asset write permission in the workspace.

next
array of object
required

Ordered steps to finish the fallback or read its outcome.

Show child attributes

Related resources

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