Landmark Conveyancing Experience API (1.0.0)

The Conveyancing API is where you quote for, instruct, and manage conveyancing work with Landmark. Whether you're referring work to a panel conveyancer or handling the cases that come your way, you do it through one API and against one shared case record.

The first thing it supports is panel conveyancing through Optimus: as an introducer you create a quote, choose a conveyancer, and instruct them on your client's behalf; as a conveyancer you pick up the cases assigned to you and keep the introducer updated as the work moves forward. That's the workflow this documentation focuses on, though the API will grow to cover more of how you connect to conveyancing over time.

Throughout, a quote becomes a case once instructed. After that, retrieve and list it through the Cases endpoints rather than Quotes. Both sides share one case record, and you only see the cases your account is party to.

Functionality is being made available in UAT as it becomes ready to test. We'll keep this section updated as each drop lands.

The Quotes and Cases endpoints have a settled schema and you can use them as a reference to start your integration work.

Your Landmark contact will confirm what's available to you and when.

The API is a REST service over HTTPS. You send and receive JSON, apart from document uploads, which use multipart/form-data, and PDF or document downloads, which return the file itself.

You'll start with UAT credentials, then move to production once your integration is ready to go live.

The API uses OAuth 2.0 with the client credentials grant. When you're onboarded you'll receive a client ID and secret. These identify your account, so there's no separate account header to send.

1. Get an access token by POSTing your credentials to the token endpoint for your environment:

• UAT: https://lmkmaster-uat.eu.auth0.com/oauth/token
• Production: https://lmkmaster.eu.auth0.com/oauth/token

{
  "client_id": "your-client-id",
  "client_secret": "your-client-secret",
  "audience": "https://api.landmarkcloudservices.com",
  "grant_type": "client_credentials"
}

You'll get back an access_token (a JWT) and an expires_in value. Cache and reuse the token until it's close to expiring rather than fetching a new one for every call.

2. Send the token on every request:

• Authorization: Bearer <access_token>

A 401 means your token is missing or invalid. A 403 means your account isn't entitled to that operation; contact support if you think that's wrong.

The API allows 1000 requests per minute per client. That limit is shared across all endpoints - it is not a separate quota per endpoint. If you exceed it you'll receive a 429 Too Many Requests response; wait briefly and retry.

Standard HTTP status codes apply: 400 validation, 401 authentication, 403 not entitled, 404 not found, 429 too many requests, 5xx server error.

When something goes wrong you'll get back a consistent JSON shape:

{
  "status": "400",
  "code": "40001",
  "title": "Validation error",
  "messages": [
    { "property": "propertyAddress.postcode", "message": "Postcode is required" }
  ]
}

Every response includes a traceresponse header that uniquely identifies your request. Quote it when you contact support so we can find it quickly.

Support Contact: TBC

Callbacks notify your system when something changes on a quote or case - for example when a case has been instructed. We POST a JSON payload to an HTTPS endpoint you provide.

Setup: before callbacks can be delivered, tell your Landmark contact which URL we should call and what authentication your endpoint requires (for example an API key header or OAuth client credentials). We'll configure the subscription against your account.

Each callback uses a common envelope. The fields outside content stay the same for every event; only content varies by eventType. See Callback Schemas for the payload of each event. More event types will be added over time with different content shapes.

Documented events include Case Status Changed (request.status-changed) and Task Completed (request.task-completed). When content.status is Instructed on a status-changed callback, the quote has been instructed and is thereafter a case - use the Cases endpoints for that resource.

Quotes are where a job begins. You build a quote for your client's transaction, get back the panel conveyancers available to you with their pricing, and instruct one of them to turn the quote into a live case.

A single request can cover a standalone transaction (one quote) or a combined sale and purchase (two quotes, one for each side). You choose what you're quoting for with a product schema, which sets the questions that apply. See Product Schemas.

To instruct, pass the conveyancerId of one of the conveyancers returned for the quote. That creates the case and makes the details available to the conveyancer you've chosen. Once instructed, the quote becomes a case and is no longer returned by quote retrieval or listing - switch to the Cases endpoints for that resource.

Once you instruct a quote it becomes a case and is thereafter retrieved and listed through these endpoints rather than Quotes. If you're the conveyancer, these are the cases assigned to you: you work them through to completion and post updates as you go. If you're the introducer, this is how you follow the work you've referred and see how it's progressing. Either way, you only see the cases your account is party to.

From here you can retrieve your cases, read the full detail of one, update its status and handler, work the task hierarchy, follow the activity history, add notes, and exchange documents.