Connect an installed TypeScript client with delegated OAuth

npm install @shodai-network/agreements-api-client

import { mkdir, readFile, rm, writeFile } from 'node:fs/promises';
import { dirname, resolve } from 'node:path';
import { ApiClient } from '@shodai-network/agreements-api-client';
import {
  OauthDelegatedSession,
  type OauthDelegatedTokenSet,
} from '@shodai-network/agreements-api-client/oauth';

const clientId = requiredEnv('OAUTH_CLIENT_ID');
const issuer = requiredEnv('OAUTH_ISSUER_URL');
const apiBaseUrl = requiredEnv('EXTERNAL_API_BASE_URL');
const tokenPath = resolve(process.env.SHODAI_TOKEN_PATH ?? '.shodai-oauth-session.json');

async function loadTokens(): Promise<OauthDelegatedTokenSet | undefined> {
  try {
    return JSON.parse(await readFile(tokenPath, 'utf8')) as OauthDelegatedTokenSet;
  } catch (error) {
    if ((error as NodeJS.ErrnoException).code === 'ENOENT') return undefined;
    throw error;
  }
}

async function saveTokens(tokens: OauthDelegatedTokenSet): Promise<void> {
  await mkdir(dirname(tokenPath), { recursive: true });
  await writeFile(tokenPath, `${JSON.stringify(tokens, null, 2)}\n`, { mode: 0o600 });
}

async function clearTokens(): Promise<void> {
  await rm(tokenPath, { force: true });
}

function requiredEnv(name: string): string {
  const value = process.env[name]?.trim();
  if (!value) throw new Error(`Set ${name} before running this client.`);
  return value;
}

const session = new OauthDelegatedSession({
  clientId,
  issuer,
  scope: 'agreements.read agreements.write',
  onTokensUpdated: saveTokens,
  onTokensCleared: clearTokens,
});

const savedTokens = await loadTokens();
if (savedTokens) {
  session.restoreTokens(savedTokens);
}

if (process.argv.includes('--disconnect')) {
  if (!savedTokens) {
    console.log('No saved session to disconnect.');
  } else {
    try {
      await session.revoke();
      console.log('Disconnected and cleared the saved session.');
    } catch (error) {
      console.error('Local token cleanup or remote revocation was not confirmed.', error);
      process.exitCode = 1;
    }
  }
} else {
  if (!savedTokens) {
    await session.loginWithLoopback();
  }

  const client = new ApiClient({
    baseUrl: apiBaseUrl,
    tokenProvider: session.tokenProvider(),
  });

  const agreements = await client.listAgreements({ limit: 5 });
  console.log(`Signed in; ${agreements.data.length} agreement(s) returned.`);
}