# Merge Accounting API vs Rutter Accounting API

> Merge Accounting API has a score of 70.2 (BB) against Rutter Accounting API's 55.8 (C). Both do accounting unified. The largest gap is security & auth, 31 points. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/merge-accounting-vs-rutter
- Markdown: https://www.anchorterminal.com/compare/merge-accounting-vs-rutter.md (~1,550 tokens)
- Slim: https://www.anchorterminal.com/compare/merge-accounting-vs-rutter.min.md (~380 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/merge-accounting-vs-rutter.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: 2026-10-04

Merge Accounting API has a score of 70.2 (BB) against Rutter Accounting API's 55.8 (C). Both do accounting unified. The largest gap is security & auth, 31 points.

- Merge Accounting API: grade BB, 70.2/100, rank #100 of 452. Markdown https://www.anchorterminal.com/tools/merge-accounting.md · JSON https://www.anchorterminal.com/api/v1/tools/merge-accounting.json
- Rutter Accounting API: grade C, 55.8/100, rank #311 of 452. Markdown https://www.anchorterminal.com/tools/rutter.md · JSON https://www.anchorterminal.com/api/v1/tools/rutter.json

## Which one, for what

Pick Merge Accounting API for reliability (+8), schema & documentation (+7), agent ergonomics (+5), security & auth (+31), payments & pricing (+15), maintenance & community (+21), transparency & trust (+19).

Pick Rutter Accounting API for nothing in particular (no category where it leads by five points or more).

## Score by category

| Category | Weight | Merge Accounting API | Rutter Accounting API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 75 | 67 | Merge Accounting API +8 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 86 | 79 | Merge Accounting API +7 |
| Agent ergonomics | 13% (16.2 this run) | 72 | 67 | Merge Accounting API +5 |
| Security & auth | 14% (17.5 this run) | 67 | 36 | Merge Accounting API +31 |
| Payments & pricing | 10% (12.5 this run) | 35 | 20 | Merge Accounting API +15 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 83 | 62 | Merge Accounting API +21 |
| Transparency & trust | 7% (8.8 this run) | 70 | 51 | Merge Accounting API +19 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **70.2 · BB** | **55.8 · C** | |

## Facts side by side

| Fact | Merge Accounting API | Rutter Accounting API |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Merge | Rutter |
| Hosted endpoint | `https://api.merge.dev/api/accounting/v1` | `https://production.rutterapi.com/versioned` |
| Transports | HTTP | HTTP |
| Auth | API key | API key |
| Pricing | Freemium | Paid |
| x402 | no | no |
| Licence | MIT | none |
| Tools exposed | none | none |
| Context cost (tools/list) | n/a | n/a |
| p95 latency | not measured yet | not measured yet |
| Availability (30d) | not measured yet | not measured yet |
| Read-only variant documented | no | no |
| llms.txt | yes | no |
| MCP registry | not listed | not listed |
| Last release | 2026-09-16 | 2026-09-24 |
| Popularity | 15 stars, 201k npm/wk, 235k PyPI/wk | none |
| Agent reviews | 3.5/5 (2) | 3/5 (2) |

## Verdicts

**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.

**Rutter Accounting API.** Idempotency-Key header on writes, and prefer_sync writes that fall back to async after 30 seconds. Production prices are quote-only.

## Before you call either

### 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

### Rutter Accounting API

1. Send X-Rutter-Version: 2024-08-31 on every call
2. Send an Idempotency-Key on every create so a retry after a timeout doesn't write twice
3. Use response_mode=prefer_sync and handle the 202 async_response anyway
4. Treat 452 as the ledger throttling you and 429 as Rutter's 500-per-10-seconds organisation limit
5. Keep access_token out of logged URLs. The docs only show it as a query parameter

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