Introduction to the Monument Bank Partner API

As of August 2026, Monument Bank offers four endpoints for approved external partner applications to carry out automated access to the base operational features of Bertha, the Bank Bot.

Endpoint consumption is approved through a consultation and discovery process in the Pavia Discord server. Head to #contact-mg and select “MB API Enquiries.”

Accessible Endpoints

Access is granted per credential, per account and per tier. A credential is issued with only the roles your integration needs, and the transaction endpoints are further scoped to the specific account threads you have been granted. Your key cannot read an account it was not given as an authorised party on the account. Transactions Create is available only with MB Premium API Access.

Securities View

GET /api/securities/market-summary returns the current market summary for every security listed on the Monument Bank order book supplying price, movement, and book state.

This is the endpoint behind any dashboard, ticker, or valuation feature you want to run outside Discord.

Commodities View

GET /api/commodities/market-summary returns pricing for every active commodity market, expressed in Diamond per commodity unit.

The feed carries pricing data only, with no book depth or volume. It is also delayed by at least thirty minutes so that the public feed cannot be used to front-run the market against traders working inside Bertha. If your use case is price discovery, reference rates, or historical charting, the delay will not matter.

Transactions View

GET /api/transactions returns up to ninety days of transfers for an account thread your credential has been granted. Pass the account’s details, and optionally a since timestamp to fetch anything after a certain point in time.

Transactions Create

POST /api/transfers/pending creates a Diamond transfer to a primary or alternative sort code, and Bertha posts Confirm and Deny controls into the source account thread for an authorised human to action. Setting the flag instant in the request body will execute immediately, but only where that source account has already completed an outbound transfer to that same destination before.

A credential on MB API Access is not issued transfer authority. Ask a Bank Director about MB Premium API Access if your integration needs to create transfers.

Billing & Usage

API access became chargeable on 1 August 2026. The first collection runs on 1 September and covers August usage.

What it costs

^*

Each read endpoint carries a monthly base fee and a monthly allowance. Beyond the allowance you are charged per block of calls.

A base fee applies only in a month where that endpoint served at least one successful request which means an endpoint you hold access to but do not call costs nothing. Blocks are started rather than pro-rated, so a single call past your allowance will allow for a whole block. Only successful responses count to your usage limit.

Choosing a tier

MB API Access is cheap for day-to-day small-business reading, but its overage is deliberately steep. It is strictly cheaper through 32 calls per read endpoint each month. The first eight-call overage block, covering 33 to 40 calls, brings it level with MB Premium API Access, so at roughly 36 calls the upgrade is already worth considering. MB Premium API Access is strictly cheaper from 41 calls and is the only tier that includes transfer creation.

Bank Directors set the tier for each credential. Run /api pricing to see both current rate cards and /api usage to see the tier attached to your credential or historic invoice. A tier move is not prorated: the whole month is billed on whichever tier the credential holds when the monthly billing run executes.

Transfer fees are separate

From September 1 2026, a 1.5% fee on Diamond transfers is taken inside each transfer with a minimum of 0.500d. Wherever a transfer is executed, this fee applies on any tier. It is disclosed in the API response, and both the amount and the fee are reserved together. A pending transfer that is denied or cancelled releases both reservations and costs nothing at all.

Seeing what you have used

Run /api usage in your Monument Bank account thread. It shows for each endpoint you use: how many calls you made, how many were included at no charge, how far past the allowance you have gone, and what that has cost so far, alongside a day by day chart of your call volume. /api pricing shows the pricing above in effect for any given month.

Anyone with balance permission on the account can run both, so if a developer maintains your integration, add them to the account with /team and they can watch usage without needing to be the account owner.

Figures for a month still in progress are usage to date and nothing is charged until the monthly update process runs. Once a month has been invoiced you can check that historical period so you can see what was charged.

Collection

Read charges are invoiced after the month ends and debited automatically from the billing account linked to your credential by Bank Directors. The charge posts into your account thread with a full breakdown of the calls it covers.