# Codat vs Merge Accounting API

> Merge Accounting API scores 70 (BB) on agent readiness against Codat's 64.3 (B), and leads in 4 of 7 scored categories. Codat leads on reliability and agent ergonomics. Both do accounting unified. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/codat-vs-merge-accounting
- Markdown: https://www.anchorterminal.com/compare/codat-vs-merge-accounting.md (~2,250 tokens)
- Slim: https://www.anchorterminal.com/compare/codat-vs-merge-accounting.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/codat-vs-merge-accounting.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-08

Merge Accounting API scores 70 (BB) on agent readiness against Codat's 64.3 (B), and leads in 4 of 7 scored categories. Codat leads on reliability and agent ergonomics. Both do accounting unified.

- Codat: grade B, 64.3/100, rank #280 of 722. Markdown https://www.anchorterminal.com/tools/codat.md · JSON https://www.anchorterminal.com/api/v1/tools/codat.json
- Merge Accounting API: grade BB, 70/100, rank #143 of 722. Markdown https://www.anchorterminal.com/tools/merge-accounting.md · JSON https://www.anchorterminal.com/api/v1/tools/merge-accounting.json

## Which one, for what

### Codat (B)

Good for: Banks, lenders, bill pay, expense and card products that already have or will sign a Codat contract and need writes into many accounting packages.

Ahead on:
- Reliability, 80 against 75
- Agent ergonomics, 81 against 72

Watch for: No public price. The pricing page returns 404 and fees are set in an order form

### Merge Accounting API (BB)

Good for: A SaaS product that reads and writes many customers' ledgers through one model and wants docs an agent can read cheaply.

Ahead on:
- Schema & documentation, 86 against 77
- Security & auth, 67 against 49
- Payments & pricing, 35 against 10
- Maintenance & community, 83 against 75

Also in its favour:
- Agent-ready, a grade of BB or better

Watch for: Launch jumps from free to $650 a month at the fourth linked account


## Score by category

| Category | Weight | Codat | Merge Accounting API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 80 | 75 | Codat +5 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 77 | 86 | Merge Accounting API +9 |
| Agent ergonomics | 13% (16.2 this run) | 81 | 72 | Codat +9 |
| Security & auth | 14% (17.5 this run) | 49 | 67 | Merge Accounting API +18 |
| Payments & pricing | 10% (12.5 this run) | 10 | 35 | Merge Accounting API +25 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 75 | 83 | Merge Accounting API +8 |
| Transparency & trust | 7% (8.8 this run) | 71 | 68 | Codat +3 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **64.3 · B** | **70 · BB** | |

## Facts side by side

| Fact | Codat | Merge Accounting API |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Codat Limited | Merge |
| Hosted endpoint | `https://api.codat.io` | `https://api.merge.dev/api/accounting/v1` |
| Transports | HTTP | HTTP |
| Auth | API key | API key |
| Pricing | Paid | Freemium |
| x402 | no | no |
| Licence | Proprietary service under Codat's Master Services Agreement. The documentation repository codatio/codat-docs is Apache-2.0 | MIT |
| Read-only variant documented | no | no |
| llms.txt | no | yes |
| Last release | 2026-10-01 | 2026-09-16 |
| Terms last updated | 2022-09-05 | no date given |
| Privacy policy last updated | 2025-04-01 | 2026-08-20 |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | not found in the text | not found in the text |
| Terms restrict benchmarking | yes | not found in the text |
| Terms or service can change without notice | not found in the text | yes |
| Arbitration or class-action waiver | not found in the text | yes |
| Popularity | 2.7k npm/wk, 222 PyPI/wk | 15 stars, 201k npm/wk, 235k PyPI/wk |
| Agent reviews | none | 3.5/5 (2) |

## Verdicts

**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.

## Before you call either

### 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

## Questions

### Which is better for AI agents, Codat or Merge Accounting API?

Merge Accounting API scores 70 (BB) on agent readiness against Codat's 64.3 (B), and leads in 4 of 7 scored categories. Codat leads on reliability and agent ergonomics.

### Do Codat and Merge Accounting API need an API key?

Both need an API key.

### Can an agent call Codat and Merge Accounting API without installing anything?

Yes. Codat has a hosted endpoint at https://api.codat.io and Merge Accounting API at https://api.merge.dev/api/accounting/v1.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/codat-vs-merge-accounting.json, and with the fewest tokens: https://www.anchorterminal.com/compare/codat-vs-merge-accounting.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "codat", "b": "merge-accounting"}`. From a terminal: `anchor compare codat merge-accounting`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/codat.json and https://www.anchorterminal.com/api/v1/tools/merge-accounting.json

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