Metadata

doc.metadata reads and rewrites the document’s Info dictionary — title, author, dates, and custom keys.

interface MetadataService {
  read(): AbortablePromise<DocumentMetadata>;
  update(patch: MetadataPatch): AbortablePromise<MetadataUpdateResult>;
}

Reading metadata#

const meta = await doc.metadata.read();
 
meta.title;    // string | null
meta.author;   // string | null
meta.created;  // ISO 8601 string | null (from /CreationDate)
meta.modified; // ISO 8601 string | null (from /ModDate)
meta.trapped;  // 'true' | 'false' | 'unknown'
meta.custom;   // Record<string, string> of non-standard Info entries

The full shape:

interface DocumentMetadata {
  title: string | null;
  author: string | null;
  subject: string | null;
  keywords: string | null;
  producer: string | null;
  creator: string | null;
  created: string | null;   // ISO 8601
  modified: string | null;  // ISO 8601
  trapped: 'true' | 'false' | 'unknown';
  custom: Record<string, string>;
}

Dates come back as ISO 8601 strings. Parsing them into Dates is the caller’s job — the engine doesn’t assume a timezone for you.

Updating metadata#

update() takes a three-state patch, the same convention used by annotation patches:

undefined — leave the field untouched
null — clear the field
a value — set the field

const result = await doc.metadata.update({
  title: 'Q2 Proposal (final)',
  subject: null,            // clear /Subject
  created: '2026-01-04T09:00:00Z', // engine formats to PDF date syntax
  custom: {
    reviewedBy: 'dana',     // set a custom key
    draftOwner: null,       // remove a custom key
  },
});
 
console.log(result.metadata.title); // re-read result

Notes:

created/modified accept ISO 8601 strings; the engine formats them into PDF date syntax (D:YYYYMMDD…) on write.
trapped has no clear form (it’s a tri-valued enum) — omit it to leave it untouched.
custom is a per-key three-state map. Reserved standard keys are rejected.
The result includes the re-read metadata plus cloud coherence pins so subsequent reads stay consistent.

Writing metadata is gated by doc.metadata.modify on the cloud. Without it, update() rejects with Forbidden.