MX Platform API vs TrueLayer

MX Platform API

Three public OpenAPI files, llms.txt, Markdown docs and a written version policy with 18 months of support and Deprecation and Sunset response headers. No price, client agreement or SLA is published, production keys need MX's approval, every calling IP address must be allowlisted, and the status page records three platform-wide error incidents since 10 July 2026.

TrueLayer

FCA and Central Bank of Ireland authorised, holding the AISP and PISP licences itself. No public pricing anywhere on the site or in the docs.

MX Platform API

1. Send Accept: application/json, Accept-Version: v20260929 and Basic auth of client_id:api_key on every call. A missing version returns 406
2. Ask the owner to allowlist the calling machine's static IP in the Client Dashboard first. Other addresses get 403, and some failed authentication returns 404
3. Test against https://int-api.mx.com with institution mxbank, username mxuser and any password. It has no aggregation throttle
4. Set your own id when creating users and members. A repeat returns 409, which makes a retried create safe
5. Expect 202 without an error when a standard aggregation is throttled (three hours by default). Balance checks stop at 5 per member every 2 hours with 429
6. Pass includes[]=merchant or includes[]=category as an array on transaction lists. A comma-separated string returns 400

TrueLayer

1. Use auth.truelayer-sandbox.com and api.truelayer-sandbox.com with a separate sandbox client; live credentials don't work there
2. Send the user's IP when they're present, or a bank allows 4 calls a day per account
3. Check the retry column of the Data API error table before retrying; codes marked No need the user or a config fix
4. Set data_access_type to one_time for a single read and skip the 90-day reauthorisation
5. Append .md to any docs URL to get the page as Markdown