Double-entry accounting your agents can rent.

A headless ledger over HTTP. Immutable entries, trigger-enforced invariants, instant reports. Pay per request with USDC on Base — no signup, no API key, no subscription.

$0.01/write · $0.002/read · USDC on Base

View API Discovery endpoint

# Create an account

POST /ledger/accounts

{"name": "Operating", "type": "asset"}

201 {"id": 1, "name": "Operating", "type": "asset", "balance": 0}

# Post a balanced transaction

POST /ledger/transactions

{"date": "2026-05-25", "description": "Revenue from API sale",

"entries": [{"account_id": 1, "amount": 5000}, {"account_id": 2, "amount": -5000}]}

201 {"id": 1, "balanced": true, "entries": 2}

# Pull a trial balance

GET /ledger/reports/trial-balance

200 {"total_debits": 5000, "total_credits": 5000, "balanced": true}

Why rent a ledger?

Real accounting, not a spreadsheet

Every transaction sums to zero across its entries. Every entry is immutable. SQLite triggers enforce these invariants — your agent can't accidentally break the books.

Pay with a header, not a signup

x402 micropayments mean your agent includes a X-PAYMENT header with a signed USDC transfer. No account creation, no API key, no monthly invoice. Pay for what you use.

Instant reports

Trial balance and general ledger on demand. Filter by date range or account. Your agent gets real-time visibility into its financial state without building reporting from scratch.

Capability tokens

Ed25519-signed JWTs with Reader, Writer, and Owner scopes. Give a sub-agent read-only access. Give a payment agent write access. Keep admin operations locked to the owner.

Reversals, not deletions

Made a mistake? Reverse a transaction. The original stays in the ledger with a full audit trail. No data is ever deleted — that's how real accounting works.

Machine-native

JSON in, JSON out. No web dashboard, no UI, no human-facing chrome. Built for agents that need accounting primitives — expense tracking, settlement, revenue recognition.

Pricing

Pay per request. No signup. No minimum. USDC on Base.

Operation	Price	Endpoints
Write	$0.01	POST accounts, POST transactions, POST reverse
Read	$0.002	GET accounts, GET transactions, GET reports
Capability token auth	Included	All endpoints (bypasses x402)

Capability token holders skip x402 — useful for agents with standing access.
x402 is for pay-as-you-go agents that don't want credentials.

API surface

# Accounts
POST   /ledger/accounts              Create account
GET    /ledger/accounts              List accounts
GET    /ledger/accounts/{id}         Get account + balance
PATCH  /ledger/accounts/{id}         Update account

# Transactions
POST   /ledger/transactions          Post balanced transaction
GET    /ledger/transactions          List transactions
GET    /ledger/transactions/{id}     Get transaction + entries
POST   /ledger/transactions/{id}/reverse  Reverse a transaction

# Reports
GET    /ledger/reports/trial-balance      Trial balance
GET    /ledger/reports/general-ledger     General ledger

# Auth
POST   /capabilities                 Mint capability token
GET    /capabilities                 List tokens
DELETE /capabilities/{jti}           Revoke token

# Discovery
GET    /health                       Service health
GET    /.well-known/x402             x402 payment info

x402 payment flow

# 1. Agent calls the API without payment
GET /ledger/accounts

# 2. Server returns 402 with payment requirements
HTTP 402 Payment Required
X-Payment: {"x402Version":1,"accepts":[{
  "scheme":"exact","network":"base",
  "maxAmountRequired":"2000",
  "asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "payTo":"0xeBe2B021a91758d52Cb5fC6BE9D651357Cb30664"
}]}

# 3. Agent signs a USDC payment and retries
GET /ledger/accounts
X-PAYMENT: <signed payment payload>

# 4. Server verifies, serves response, settles
HTTP 200 OK
[{"id":1,"name":"Operating","type":"asset","balance":5000}]

Accounting for autonomous agents.

No software to install. No dashboard to learn. Just HTTP and USDC.

Discovery endpoint novadyne.ai