Zapier - FlowSign

You can automate FlowSign with Zapier using Zapier’s own webhook and HTTP steps: trigger a Zap when a package completes, or create and send a package from another system through a Zap.

Receiving events

Create a webhook endpoint in FlowSign at Settings > Webhooks (my.flowsign.app/settings/webhooks), or with the API (see Webhooks).

In your Zap, add Webhooks by Zapier as the trigger app and choose the Catch Hook event.
Zapier gives you a catch URL. Paste it into the endpoint’s URL field in FlowSign.
Tick the events to subscribe to (for example Package Completed) and save. FlowSign shows the endpoint’s signing secret once; store it.

Every delivery is a POST with three headers and a JSON body:

Header	Value
`X-FlowSign-Event`	The event name, for example `PACKAGE_COMPLETED`
`X-FlowSign-Delivery-Id`	A stable id for this delivery; retries reuse it
`X-FlowSign-Signature`	Hex-encoded HMAC-SHA256 of the raw body, keyed with the endpoint secret

{
  "event": "PACKAGE_COMPLETED",
  "timestamp": "2026-09-17T03:40:11.000Z",
  "data": {
    "packageId": "pkg_9f3c2e",
    "packageTitle": "Employment agreement: Ana Reid",
    "completedAt": "2026-09-17T03:40:10.884Z"
  }
}

data differs per event. See Events for every event’s shape.

Verifying the signature

Skipping verification means your Zap acts on any unauthenticated POST to its catch URL, not just genuine FlowSign deliveries.

Compute a hex HMAC-SHA256 of the raw body with the endpoint secret and compare it to X-FlowSign-Signature. The Catch Hook event parses the body into fields before your Zap sees it, so re-serialising those fields to JSON isn’t guaranteed to match the exact bytes FlowSign signed (whitespace and key order can differ). For verification that has to match byte-for-byte, use the Catch Raw Hook event instead, which passes the unparsed body and headers through. Add a Code by Zapier step (JavaScript) after the trigger:

const crypto = require("crypto");

const expected = crypto
  .createHmac("sha256", inputData.secret)
  .update(inputData.rawBody)
  .digest("hex");

output = { valid: expected === inputData.signature };

Map inputData.rawBody and inputData.signature from the raw hook’s body and X-FlowSign-Signature header, and inputData.secret from a Zapier storage value or environment-style input holding the endpoint secret. Follow with a Filter by Zapier step that only continues when valid is true.

Calling the API

Use Webhooks by Zapier’s Custom Request action for any FlowSign API call. Base URL: https://my.flowsign.app. Every request needs:

Header	Value
`Authorization`	`Bearer fsk_your_key_here`
`X-Workspace-Id`	Optional; the workspace to act in. Omit to use the organisation’s default workspace.

Create the key at Settings > API keys; see Authentication.

List packages

Method GET, URL https://my.flowsign.app/api/v1/packages?status=IN_PROGRESS.

{
  "data": {
    "packages": [
      {
        "id": "pkg_9f3c2e",
        "title": "Employment agreement: Ana Reid",
        "status": "IN_PROGRESS",
        "description": null,
        "recipients": [
          { "name": "Ana Reid", "email": "[email protected]", "action": "Sign", "actionType": "SIGNER", "signed": false }
        ],
        "documentsCount": 1,
        "signingProgress": { "completed": 0, "total": 1 },
        "createdAt": "2026-09-17T01:12:44.000Z",
        "updatedAt": "2026-09-17T01:12:50.000Z",
        "expiresAt": null,
        "completedAt": null
      }
    ],
    "totalCount": 1,
    "page": 1,
    "pageSize": 25
  }
}

Create a package from a template

Method POST, URL https://my.flowsign.app/api/v1/packages/from-template, with a JSON body:

{
  "templateId": "tmpl_abc123",
  "recipients": [
    { "role": "Employee", "name": "Ana Reid", "email": "[email protected]" },
    { "role": "Manager", "name": "Ben Toa", "email": "[email protected]" }
  ],
  "fields": { "start_date": "1 October 2026" },
  "externalId": "order_4471",
  "status": "sent"
}

role must match one of the template’s role names and fields keys must match its merge field keys; a mismatch returns 422 with the unknown or missing names in details. status is "draft" (default) or "sent", which sends immediately. externalId is optional and makes the call idempotent: retrying with the same value returns the existing package instead of creating a duplicate.

{ "data": { "packageId": "pkg_9f3c2e", "externalId": "order_4471", "status": "IN_PROGRESS" } }

Creating requires the key’s user to have the send permission; see Errors for the full status code list.

Plan and cost notes

Webhooks by Zapier is a premium Zapier app, so both the Catch Hook trigger and the Custom Request action need a paid Zapier plan.

​Receiving events

​Verifying the signature

​Calling the API

​List packages

​Create a package from a template

​Plan and cost notes

Receiving events

Verifying the signature

Calling the API

List packages

Create a package from a template

Plan and cost notes