Bulk Inscriptions (bulk-files)

bulk-files is an inscription mode designed for multi-file packages where each file should be inscribed as its own standalone HCS-1 topic (as opposed to Hashinals, where media + JSON metadata are paired).

This is the mode used by Registry Broker skill publishing to inscribe a whole skill package (often 20+ files) efficiently.

When to use bulk-files

HCS-26 skill packages that contain multiple artifacts (docs, schemas, code samples, etc.)
Any workflow where you want one job submission, but you need one topic per file
A two-step flow where you first inscribe the files, then inscribe a manifest that references them (for example skill.json)

How it works

Create a ZIP that contains the files you want to inscribe.
Call inscribe(...) with mode: 'bulk-files' and mimeType: 'application/zip'.
The inscription service unpacks the ZIP and inscribes each file separately.
The completed job includes a per-file result list in inscription.files.bulkUploads.

Each bulkUploads[] entry typically includes:

name: file path in the ZIP
topicId: topic created for that file's inscription
uri: HRL-like identifier (often hcs://1/<topicId>)
mimeType, hash, and message counters when available

Standards SDK example

import fs from 'node:fs';
import { inscribe } from '@hashgraphonline/standards-sdk';

const zipBuffer = fs.readFileSync('./my-skill-package.zip');

const res = await inscribe(
  {
    type: 'buffer',
    buffer: zipBuffer,
    fileName: 'my-skill-package.zip',
    mimeType: 'application/zip',
  },
  {
    accountId: '0.0.1234',
    privateKey: process.env.HEDERA_PRIVATE_KEY as string,
    network: 'testnet',
  },
  {
    mode: 'bulk-files',
    waitForConfirmation: true,
    metadata: {
      type: 'my-bulk-package',
      fileCount: 20,
    },
  },
);

const bulkUploads = res.inscription?.files?.bulkUploads ?? [];
for (const upload of bulkUploads) {
  console.log(upload?.name, upload?.topicId, upload?.uri);
}

Registry Broker skill publishing

If you publish skills through the Registry Broker, you do not call inscribe(...) directly from your frontend. The client posts a publish job to the broker and the broker performs the bulk inscription server-side.

import { RegistryBrokerClient } from '@hashgraphonline/standards-sdk';

const client = new RegistryBrokerClient({
  baseUrl: 'https://hol.org/registry/api/v1',
});

await client.authenticateWithLedgerCredentials({
  accountId: '0.0.1234',
  network: 'hedera:testnet',
  hederaPrivateKey: process.env.HEDERA_PRIVATE_KEY,
});

const files = [
  {
    name: 'SKILL.md',
    mimeType: 'text/markdown',
    base64: Buffer.from('# My Awesome Skill\n\nThis skill does awesome things.').toString('base64'),
  },
  {
    name: 'skill.json',
    mimeType: 'application/json',
    base64: Buffer.from(JSON.stringify({ name: 'my-awesome-skill', version: '1.0.0' })).toString('base64'),
  },
  // ... and other files
];

const quote = await client.quoteSkillPublish({ accountId: '0.0.1234', files });
const publish = await client.publishSkill({
  accountId: '0.0.1234',
  quoteId: quote.quoteId,
  files,
});

const job = await client.getSkillPublishJob(publish.jobId, { accountId: '0.0.1234' });
console.log(job.status);

Internally, the broker:

Inscribes the full file set as one ZIP using mode: 'bulk-files', producing one topic per file.
Builds the HCS-26 manifest (skill.json + file HRLs) and inscribes that separately so the manifest can reference the file topics.

For more context on skill publishing, see Skills Upload & Discovery.

Explore Registry Hubs