Asset types and accounts
Define a thing you count, such as a currency, a credit or a stock unit, and give it its own precision. Then open accounts for it. Every account declares the lowest balance it may reach.
Product
One ledger for money, credits and stock
Ledger is a hosted double-entry ledger with an API. Your systems post movements, and the ledger keeps books that always balance, never forget and can be proved at any moment.
What you get
Seven things the API does
Balanced transactions
A transaction lists where value comes from and where it goes. It is accepted whole or refused whole. There is no partial write.
Reserve now, settle later
Set money or stock aside without moving it. Complete the hold when the sale goes through, or release it yourself. Unfinished holds expire on a schedule you choose.
Balances, past and present
Read what is posted and what is available now, or the balance as it stood at an earlier moment. Statements are paged, and a page you have already read will not shift underneath you.
Safe retries
Every write carries a key you derive from your own record. Send it twice and the second call returns the first answer without moving anything again.
Ledgers for your own clients
A client gets an isolated ledger under your account, along with their own accounts, records and keys. You suspend and restore them through the API.
A machine-readable contract
The full API is published as an OpenAPI document, and a plain-text contract written for software agents is served beside it.
The ledger model
What happens when you post a transaction
-
1. Request
Your system posts a transaction with a key of its own choosing.
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2. Checks
Balance, floors, account state and your key are all verified together, under lock.
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3. Journal
The entries are written permanently, or nothing is written at all.
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4. Balances
Posted and available balances update in the same step. A background check keeps proving they add up.
A walk through the API
Eight steps, each captured from a running instance
The guide shows every request and response. The runnable tour in the ledger repository performs them against a live tenant.
Step 1
Authenticate
One credential, scoped to your tenant. Its role decides whether it can read, post, administer, or manage clients.
Step 2
Define assets and accounts
Create an asset type such as GBP with two decimal places, a control account for money entering the system, and customer accounts floored at zero.
Step 3
Move value
Post a transfer of 100.00 from the control account to a customer. The response shows the available balance of both accounts after the move.
Step 4
Retry safely
Send the same request again with the same key, and the original answer comes back without the money moving twice. Send a different body under the same key and it is refused.
Step 5
Read the books back
The balance now, the statement page by page, and the transaction itself.
Step 6
Reserve and settle
Place a hold of 25.00, then complete one hold and release another. Anything you leave unresolved is released when it expires.
Step 7
Handle refusals
An overdraft attempt, an unbalanced request and an invalid timestamp all return a clear code that names the field. Retry only the temporary ones.
Step 8
See isolation at work
Ask for a record with another tenant’s credential and it does not exist. Nothing in the answer confirms that the record is there.
POST /v1/transactions
Idempotency-Key: payout-2026-09-05-0001
Content-Type: application/json
{
"description": "welcome credit",
"entries": [
{ "account_id": "<control account>", "direction": "debit", "amount": "100.00" },
{ "account_id": "<customer account>", "direction": "credit", "amount": "100.00" }
]
}
201 Created (a second identical request answers
Idempotent-Replay: true <--- with the same body and this header)# money and goods in one write — or neither
POST /v1/transactions
{
"description": "sale: 2 widgets for 50.00",
"entries": [
{ "account_id": cash, "direction": "debit", "amount": "50.00" },
{ "account_id": customer, "direction": "credit", "amount": "50.00" },
{ "account_id": stock, "direction": "credit", "amount": "2" },
{ "account_id": shipped, "direction": "debit", "amount": "2" }
]
}
# unbalance either asset and the whole write is refused:
# 422 UNBALANCED_TRANSACTION{
"error": {
"code": "INSUFFICIENT_AVAILABLE",
"message": "insufficient available",
"details": [{
"account_id": "019fdfe1-…",
"available_minor": "7500",
"balance_floor_minor": "0"
}]
}
}
# how to react, by class
# 409 + Retry-After -> wait, then retry with the SAME key
# 422 / 404 / 403 -> a fact about your request; fix it or surface it
# 5xx -> temporary; your key is not consumedRead the full walk-through in the getting-started guide.
Implementation path
From first key to reconciled reporting
1
Get a key
Request access, and we provision a tenant and mint your first key. A partner key lets you create ledgers for your own clients.
2
Model your books
Choose asset types and precision, then decide which accounts are customer-facing, floored at zero, and which are control accounts.
3
Post from your system of record
Derive a request key from your own document, such as an order or a statement line. A retry then cannot double-post.
4
Reconcile and report
Pull statements and as-of balances into your reporting. The ledger keeps proving its own trial balance in the background.
The API surface
20 endpoints, generated from the served contract
This table is produced from the live OpenAPI document and checked against it before every deploy. It cannot drift from what the service actually serves.
| Group | Method | Path | What it does |
|---|---|---|---|
| Accounts and balances | GET | /v1/accounts | List your accounts, page by page |
POST | /v1/accounts | Open an account for an asset type and set its floor | |
GET | /v1/accounts/{account_id} | Read one account | |
PATCH | /v1/accounts/{account_id} | Freeze an account, close it, or adjust its floor | |
GET | /v1/accounts/{account_id}/balance | The current balance, both posted and available | |
GET | /v1/accounts/{account_id}/balance-as-of | The balance at any past moment, on either clock | |
GET | /v1/accounts/{account_id}/entries | The statement of every entry on the account, in order and page by page | |
| Reference data | GET | /v1/asset-types | List the asset types you have defined |
POST | /v1/asset-types | Define something you count, such as a currency, a credit or a stock unit, and give it a precision | |
PATCH | /v1/asset-types/{asset_type_id} | Retire an asset type created by mistake, or bring it back. Its code, kind and precision never change. | |
| Partners and sub-tenants | GET | /v1/sub-tenants | List your clients |
POST | /v1/sub-tenants | Create an isolated ledger for one of your own clients | |
PATCH | /v1/sub-tenants/{sub_tenant_id} | Suspend or restore a client | |
GET | /v1/sub-tenants/{sub_tenant_id}/keys | List a client’s keys and when they were last used | |
POST | /v1/sub-tenants/{sub_tenant_id}/keys | Issue a key for a client | |
DELETE | /v1/sub-tenants/{sub_tenant_id}/keys/{key_id} | Revoke a client’s key immediately | |
| Transactions and holds | POST | /v1/transactions | Post a balanced transaction, or place a hold |
GET | /v1/transactions/{transaction_id} | Read one transaction and its entries | |
POST | /v1/transactions/{transaction_id}/commit | Settle a hold | |
POST | /v1/transactions/{transaction_id}/void | Release a hold |
Explore it live: API explorer · OpenAPI document · llms.txt for software agents · API reference.
Free today. Access is provisioned personally by RODMENA.
Tell us what you keep books of and we will set up a tenant, mint your first key and walk you through the tour.