Retrieves a single dossier (a KYC/KYB case) with the full detail rendered in
the Bynn dashboard: dossier fields, all dossier media, and every applicant
(entity) with their personal information, identity documents, captured media
and all liveness selfie frames — each media asset tagged with its type and
a download URL.

Getting the dossier id

The :id accepts the prefixed dossier token (dossier_xxx) or the humanized
token (e.g. U45XZQE9N). You receive dossier_id in the session.completed,
identity_document.* and decision.* webhook events, and as rel.url on the
dossier webhook payload. This endpoint is the supported way to fetch an
applicant's liveness selfie and ID-document (front/back) images after a session
completes.

⚠️ Media URLs are short-lived — download immediately

Every url in the response (media[].url, entities[].media[].url,
entities[].identity_documents[].images[].url, entities[].liveness_images[].url)
is a presigned, short-lived link — it typically expires within ~5 minutes.
Download and persist the files on your side immediately upon receiving the
response. Do not store or cache the URLs themselves; request a fresh dossier
to mint new URLs when needed.

Response

See DossierEntity. Notable fields:

• id — prefixed dossier_<token>
• type — kyc, kyb, doc
• status — business status (open, approved, rejected, …)
• media[] — every dossier-level asset ({ type, name, page, url, created_at })
• entities[] — applicants, each with identity_documents[], media[] and
  liveness_images[]

Errors

• 401 authentication_error — missing, malformed, or revoked private key.
• 404 not_found — no dossier with the given identifier exists in this organization.