Developers

Build on SynthCounsel.

Public REST API + signed outbound webhooks for the firm tier. Bearer-token auth. OpenAPI 3.0 spec. Build your integration against a real legal-document engine instead of writing one from scratch.

API reference OpenAPI spec Generate keys

Three things you can build

Custom matter intake

Embed an intake form on your firm site. POST to /api/v1/matters with a Bearer token and the matter shows up in /firm. Webhook subscriptions fire matter.created back to your CRM.

Two-way Clio replacement

Listen to time_entry.created and time_entry.pushed_to_clio webhooks. Push your time-tracker into SynthCounsel, get back the same data once it hits Clio. Saves the integration team a sprint.

Automation triggers

document.approved fires when an attorney signs off on a draft. Use it to kick off DocuSign envelopes, calendar events, Slack notifications — anything you can attach to a webhook.

Quickstart

30-second cURL test. Replace YOUR_KEY with a key generated at /firm/settings/api-keys.

# 1. List your matters
curl -H "Authorization: Bearer YOUR_KEY" \
  https://synthcounsel.com/api/v1/matters?limit=5

# 2. Create a matter
curl -X POST \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"name":"Smith v. Acme","client_name":"John Smith","jurisdiction":"CA"}' \
  https://synthcounsel.com/api/v1/matters

# 3. Log billable time
curl -X POST \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"matter_id":"<from step 2>","duration_minutes":45,"description":"Initial client call"}' \
  https://synthcounsel.com/api/v1/time-entries

Webhook signatures

Every webhook delivery includes an HMAC-SHA256 signature in the X-SynthCounsel-Signature header as sha256=<hex>. Verify before processing:

// Node.js / TypeScript
import { createHmac, timingSafeEqual } from 'node:crypto';

function verifyWebhook(req: Request, secret: string, body: string): boolean {
  const header = req.headers.get('x-synthcounsel-signature') ?? '';
  const expected = 'sha256=' + createHmac('sha256', secret).update(body).digest('hex');
  return header.length === expected.length &&
    timingSafeEqual(Buffer.from(header), Buffer.from(expected));
}

Rate limits

· 60 requests / minute / key (default).
· Headers: X-RateLimit-Limit, X-RateLimit-Remaining.
· On 429: honor the Retry-After seconds header.
· Need a higher limit? Email api@synthcounsel.com.

Versioning

The current version is /v1. Breaking changes ship on a new path (/v2) with a deprecation window for the previous version. Additive changes (new fields, new endpoints) ship to the existing version without version-bump.

Growth tier required

The public API is included with the SynthCounsel Growth tier. Solo and Small tiers do not get key issuance — upgrade to enable. Existing keys revoke immediately if subscription lapses.