---
title: "Start an OAuth Observer Mode connection"
method: POST
path: "/observer/oauth/start"
---

# Start an OAuth Observer Mode connection

`POST /observer/oauth/start`

## Request

- Base URL: `https://sendinel.ai/api/v1`
- URL: `https://sendinel.ai/api/v1/observer/oauth/start`
- Auth: one of:
  - HTTP bearer
  - OAuth 2 (authorization code, authorization URL `https://sendinel.ai/oauth/authorize`, token URL `https://sendinel.ai/oauth/token`)

Requires a service API key with the service:provision scope. Returns a provider authorization URL for Synchronex to redirect a user through an OAuth consent flow. The callback writes a connection_mode=observe platform connection and returns the browser to Synchronex.

## Request body

- object
  - `synchronex_account_id` string, required
  - `provider` 'hubspot' | 'shopify' | 'stripe' | 'calendly', required
  - `return_to` string, uri, required
  - `state` string, required
  - `label` string
  - `workspace_hint` string

## Response `200`

Provider authorization URL

- object
  - `authorization_url` string, uri, required

## Other responses

- `403`: Signed project does not own this Synchronex account
- `404`: Synchronex account is not linked to an active Sendinel project
- `422`: Missing or invalid observer OAuth request fields

---

[API](https://skmtc.dev/sendinel/apis/sendinel-api.md) · [All operations](https://skmtc.dev/sendinel/apis/sendinel-api/llms.txt) · [OpenAPI document](https://skmtc.dev/sendinel/apis/sendinel-api/revisions/01f916b0c916?raw)