Australian bank rates API: CDR vs RateSonar vs open-banking-mcp

Checked 4 November 2026

Most developers start with the Consumer Data Right (CDR) product data that each bank publishes: free, public and authoritative, but one endpoint per bank and current products only. RateSonar's API and MCP server put the same kind of data behind one call, with dated history from June 2026. open-banking-mcp is a small community package that lets an AI client query those same bank endpoints live.

Checked 4 November 2026. I publish RateSonar, so read the RateSonar column with that in mind. Where the CDR or another option is better, I say so below.

The three options side by side

Ways to read Australian bank rates, compared on 4 November 2026
Attribute	CDR product data, direct	RateSonar API and MCP	open-banking-mcp (npm)
Who runs it	Each bank publishes its own endpoint under the CDR Data Standards. The Data Standards Body writes the standards; the CDR Register lists the banks.	RateSonar (this site).	An individual: npm publisher eaccmk, author name Millan Kaul. Not a bank or government project.
Coverage	The CDR Register listed 116 banking brands on 4 November 2026; 115 had a product endpoint address. Products per bank vary (Alex.Bank listed 6).	206 lenders and 4,145 current product rows as at 3 November 2026 (read 4 November 2026, 11:55am AEDT). Includes lenders captured from their websites as well as CDR feeds.	Its README says 121+ Australian banks. It reads them through the CDR Register and each bank's public endpoint, so it can only see what banks publish.
Auth needed	None for product data. Account and transaction data are a different matter: they need a customer's consent and an accredited recipient.	None for the MCP server or the public HTTP endpoints. Past 25 calls a day without an account, a free sign-in or API key is asked for.	None. It runs on your machine and calls the public bank endpoints.
Format	JSON over HTTPS. GET /cds-au/v1/banking/products lists products; GET /banking/products/{productId} returns one with its rates. Send x-v and x-min-v version headers.	MCP (streamable HTTP, JSON-RPC) with tools such as find_products, compare_rates and rate_history. HTTP: GET /v1/catalog, /v1/series, /v1/changes, /v1/tiers.	MCP over stdio (npx open-banking-mcp), or self-hosted over HTTP/SSE. Eleven tools; compare tools return sorted tables for chat.
Freshness	Live from the bank. The Data Standards set no update interval for product data that I found; each product carries a lastUpdated time. The standards' data-latency wording asks for data in line with the bank's own channels.	Captured daily; the data I read was as at 3 November 2026. Every rate carries the day it was recorded.	Live: each question calls the banks. Its search-all-banks tools show progress while they query.
History	None. The endpoint lists products currently openly offered. Keep your own snapshots if you want history.	From 12 June 2026 for website captures and 14 June 2026 for CDR product listings, with each point marked recorded, carried forward or derived. Without a key a series call returns the last 31 days.	None published. It answers from the banks' current data.
Cost	Free.	Free within fair use. More usage on request.	Free; MIT licence.
MCP support	No official MCP server. You write the client, or use a package that wraps it.	Yes, hosted. Add https://api.ratesonar.com as a remote MCP server; no install.	Yes, local. Install and run it with Node.
Rate limits	The standards let a bank throttle or reject public traffic above 300 transactions a second in total across all callers. Each bank's own limit is not set by the standard; I did not test them.	No account: 60 calls a minute and 25 a day per address. Signed in: 300 a minute and 1,000 a day. Claude and ChatGPT servers share higher pools.	No limit of its own that I found in the code. Each bank's limit applies, and it reports a bank's HTTP 429 as "rate-limited".
Latest release	The standards version each endpoint: Get Products v5 was required from 13 July 2026.	Server card version 0.1.0.	1.0.6, published 2 May 2026. Nothing newer on npm at 4 November 2026.

RateSonar figures were read from ratesonar.com/sonar/rates.json on 4 November 2026 at 11:55am AEDT. CDR figures were read from the CDR Register and a bank's own endpoint the same morning.

When the CDR direct is the better choice

The CDR endpoints are free, public and come from the bank itself. If you need one bank's current figure, or you do not want a third party in the chain, call the bank. Get the list of banks from the CDR Register (send x-v: 2), then call each bank's productBaseUri plus /cds-au/v1/banking/products.

The cost is your own plumbing: one host per bank, a list call that carries no rates, a detail call for every product, version headers, paging, and your own snapshots if you want a history.

Where RateSonar adds something

One call across many lenders, with one set of fields.
Dated history from June 2026, with each point marked as recorded, carried forward or derived.
A hosted MCP server, so Claude, ChatGPT or Cursor can ask in plain words with nothing to install.

Where it does not: it is a recorded copy, not the bank's live system; it has no history before 12 June 2026; and it cannot see a product a bank has not published. For an agent, start at Connect your agent.

About open-banking-mcp

Several projects use similar names, so to be exact: this page means the npm package open-banking-mcp, version 1.0.6, MIT licence, published by npm user eaccmk (author name Millan Kaul) on 2 May 2026. Its README describes an MCP server for Australian CDR banking data. Other GitHub repositories with similar names cover other countries and are not covered here.

I read the published package, not its source repository: the GitHub address listed on npm returned a 404 on 4 November 2026. I have not run it. It is a sensible way to put the live bank endpoints in front of an AI client on your own machine. It does not add history or normalisation, and it is a single-maintainer package.

Common questions

Is there a free API for Australian bank interest rates?

Yes. Under the Consumer Data Right, banks publish their product data, including interest rates, on public endpoints that need no key and no sign-up. The CDR Register lists each bank's address. RateSonar's API and MCP server are also free within fair use and put many banks behind one call.

Do I need CDR accreditation to read product rates?

No. Product data endpoints are unauthenticated, and an unauthenticated call to a bank's product endpoint returned HTTP 200 on 4 November 2026. Accreditation and a customer's consent are needed for account and transaction data, not for the products a bank advertises.

How often do banks update CDR product data?

The Data Standards do not set an update interval for product data that I could find. Each product has a lastUpdated timestamp, so read it and decide how stale is too stale. The one product I inspected, at Alex.Bank, was last updated on 29 October 2026.

Does the CDR product list include interest rates?

Not in the list call. On 4 November 2026 the list response for Alex.Bank had names, categories, descriptions and lastUpdated, with no rates. The rates (depositRates or lendingRates) were in the product detail call, which is one request per product.

Can Claude or ChatGPT read Australian bank rates?

Yes, through an MCP server. Add https://api.ratesonar.com as a remote MCP server in Claude, ChatGPT, Cursor or VS Code (steps at ratesonar.com/agents). Or run open-banking-mcp locally with Node. In both cases check the date on each rate before quoting it.

When should I use the CDR endpoints instead of RateSonar?

Use them when you need the bank's own live figure, full detail for a single bank, or no third party in the chain. RateSonar is a recorded copy: it can lag a bank's own page, covers only what it has captured, and has no history before June 2026. It helps when you want one call across many banks, normalised fields, dated history or a ready-made MCP server.

Sources

All checked 4 November 2026.

CDR Data Standards: Get Products, Get Product Detail, pagination and traffic thresholds · Product endpoints, page-size default 25 and maximum 1,000, x-v versioning, the Get Products v5 date, the 300 TPS public-traffic threshold, the data-latency wording, and that product endpoints are unauthenticated.
CDR Register API: Get Data Holder Brands Summary · 116 banking brands, 115 with a productBaseUri, read without credentials on 4 November 2026.
Consumer Data Right (cdr.gov.au) · Who runs the CDR and where the current provider list sits.
Data Standards Body (consumerdatastandards.gov.au) · The body that writes the Data Standards.
A bank's own product endpoint (Alex.Bank, from the register) · An unauthenticated call returned HTTP 200; the list had no rates and the detail call did (see the rate-field FAQ).
RateSonar public rates file · 206 lenders and 4,145 headline product rows as at 3 November 2026, read 4 November 2026 at 11:55am AEDT.
RateSonar API catalogue · 27 standard series, read without a key on 4 November 2026.
RateSonar llms.txt · Usage limits, the 31-day anonymous window, capture start dates and the HTTP endpoints.
RateSonar MCP server card · Remote streamable-HTTP MCP server at api.ratesonar.com.
open-banking-mcp on npm · Name, version 1.0.6, MIT licence, publisher eaccmk (Millan Kaul), first published 1 May 2026, last published 2 May 2026.
open-banking-mcp 1.0.6 package README and code (npm tarball) · The tool list, the 121+ banks claim, the Australian CDR scope, and that it calls the CDR register and each bank's public API.