---
title: API routing reference
description: The request Finerlise sends to your routing endpoint, and the replies it understands.
icon: server
search:
  keywords:
    [api routing, routing webhook, response.routing, signature, next page]
---

[API routing](/logic/api-routing) is available on **Enterprise**.

## Request

Finerlise sends a `POST` with a JSON body when the configured page is completed, or after submission:

```json
{
  "event": "response.routing",
  "phase": "page",
  "createdAt": "2026-10-08T12:00:00.000Z",
  "formId": "3c9d2b1a-7e4f-4a6b-8c2d-1f0e9a8b7c6d",
  "formTitle": "Customer support",
  "responseId": null,
  "completedPage": {
    "id": "…",
    "sourceId": "…",
    "title": "Your account",
    "order": 0
  },
  "answers": [
    {
      "fieldId": "…",
      "label": "Customer ID",
      "type": "SHORT_TEXT",
      "value": "C-1042",
      "rawValue": "C-1042"
    }
  ],
  "values": { "<fieldId>": "C-1042" },
  "pages": [
    { "id": "…", "sourceId": "…", "title": "Priority support", "order": 1 }
  ],
  "endPages": [
    {
      "id": "…",
      "sourceId": "…",
      "name": "Book a call",
      "isDefault": false,
      "order": 0
    }
  ]
}
```

`phase` is `page` between pages and `submission` after the form is submitted. `responseId` is set in the `submission` phase.

## Headers

| Header | Value |
| --- | --- |
| `Content-Type` | `application/json` |
| `X-Finerlise-Event` | `response.routing` |
| `X-Finerlise-Signature` | `sha256=<hex HMAC-SHA256 of the raw body>`, using the routing secret (`fnr_route_…`) |
| Your custom headers | Up to 20, each up to 1,000 characters. |

Verify the signature the same way as for [webhooks](/developers/webhooks-reference#verify-the-signature).

## Reply

Reply `200` with JSON (up to 64,000 characters) within your timeout (3–30 seconds). Redirects aren't followed.

```json
{
  "next": "Priority support",
  "fields": { "tier": "gold" }
}
```

| Key | Meaning |
| --- | --- |
| `next` (or your response path, which can be nested like `routing.target`) | Where to go: a page title or ID, an end page name or ID, `end`/`submit`/`complete`, an `http(s)://` URL, or `next`/`default`. Matching is case-insensitive. |
| `fields` | Values for **API response** blocks, keyed by their **API response key**. Up to 50 keys; text, numbers or booleans up to 500 characters each. |
| `error` | A message (up to 280 characters), or `{ "message": "…" }`, shown to the respondent, who stays on the current page. |

If the call fails, times out or returns something unreadable, the form continues along its default path.