Basiq vs MX Platform API

Basiq

Ten public OpenAPI files, an llms.txt index with Markdown twins and a free self-serve sandbox let an agent start on test data. Live access needs a 12-month plan with an unpublished platform access fee, no SLA or security.txt was found, and the privacy policy says collected content may be kept indefinitely.

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.

Basiq

1. Send the API key verbatim after Basic in the Authorization header of POST /token. Base64-encoding it returns a 400.
2. Send basiq-version: 3.0 on the token request, cache the bearer token for its 60 minutes, and stay under 1,500 token requests per 5 minutes.
3. Send the account holder through the hosted Consent UI in a browser with a CLIENT_ACCESS token bound to their userId. The API alone cannot create a first connection on version 3.0.
4. Poll GET /jobs/{jobId} until verify-credentials, retrieve-accounts and retrieve-transactions all read success before reading accounts or transactions.
5. Follow links.next on GET /users/{userId}/transactions. A page holds at most 500 items, and pending transactions get new ids on each refresh.

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