Codat vs Merge Accounting API

Codat

Public OpenAPI specs, an Idempotency-Key header on writes, Retry-After on 429 and a written three-month deprecation notice suit an agent that retries. Access is the limitation. No price or self-serve signup is published, the general Accounting API is closed to new clients, and API keys carry no scopes.

Merge Accounting API

12 accounting platforms behind one set of common models, with writes. Launch jumps from free to $650 a month at the fourth linked account.

Codat

1. Send Authorization: Basic <base64 of the API key> to https://api.codat.io. The Portal shows the ready-made header value
2. Send a new GUID as Idempotency-Key on every POST and PATCH, and reuse the same key when retrying after a 429
3. Treat writes as asynchronous on most APIs. Keep the push operation key and wait for the {dataType}.write.successful or .unsuccessful webhook
4. Call the Get model (options) endpoint for the connection before a create or update, because required fields differ by accounting package
5. Filter with query=modifiedDate>... and keep pageSize at 100. The daily quota is 1,000 requests times one plus the number of active connected companies

Merge Accounting API

1. Call GET /invoices/meta/post for the linked account first. Required fields differ by platform
2. Bills and sales invoices are one model. Set type to ACCOUNTS_PAYABLE or ACCOUNTS_RECEIVABLE
3. Append .md to any docs URL for the Markdown twin
4. Check sync_status before reading a freshly linked account. Common models fill in over the first sync
5. Look the record up before retrying a POST that timed out. There's no idempotency key