# Apideck Accounting API + MCP vs FreeAgent API

> Apideck Accounting API + MCP has a score of 73.2 (BB) against FreeAgent API's 57.6 (C). Both do accounting ledger. The largest gap is schema & documentation, 42 points. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/apideck-accounting-vs-freeagent
- Markdown: https://www.anchorterminal.com/compare/apideck-accounting-vs-freeagent.md (~1,600 tokens)
- Slim: https://www.anchorterminal.com/compare/apideck-accounting-vs-freeagent.min.md (~380 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/apideck-accounting-vs-freeagent.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

Apideck Accounting API + MCP has a score of 73.2 (BB) against FreeAgent API's 57.6 (C). Both do accounting ledger. The largest gap is schema & documentation, 42 points.

- Apideck Accounting API + MCP: grade BB, 73.2/100, rank #60 of 452. Markdown https://www.anchorterminal.com/tools/apideck-accounting.md · JSON https://www.anchorterminal.com/api/v1/tools/apideck-accounting.json
- FreeAgent API: grade C, 57.6/100, rank #291 of 452. Markdown https://www.anchorterminal.com/tools/freeagent.md · JSON https://www.anchorterminal.com/api/v1/tools/freeagent.json

## Which one, for what

Pick Apideck Accounting API + MCP for schema & documentation (+42), agent ergonomics (+33), security & auth (+22), maintenance & community (+20).

Pick FreeAgent API for reliability (+10).

## Score by category

| Category | Weight | Apideck Accounting API + MCP | FreeAgent API | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 75 | 85 | FreeAgent API +10 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 92 | 50 | Apideck Accounting API + MCP +42 |
| Agent ergonomics | 13% (16.2 this run) | 88 | 55 | Apideck Accounting API + MCP +33 |
| Security & auth | 14% (17.5 this run) | 66 | 44 | Apideck Accounting API + MCP +22 |
| Payments & pricing | 10% (12.5 this run) | 30 | 30 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 80 | 60 | Apideck Accounting API + MCP +20 |
| Transparency & trust | 7% (8.8 this run) | 76 | 78 | FreeAgent API +2 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **73.2 · BB** | **57.6 · C** | |

## Facts side by side

| Fact | Apideck Accounting API + MCP | FreeAgent API |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Apideck | FreeAgent |
| Hosted endpoint | `https://unify.apideck.com/accounting` | `https://api.freeagent.com/v2` |
| Transports | HTTP, Streamable HTTP, stdio | HTTP |
| Auth | API key | OAuth |
| Pricing | Paid | Your plan |
| x402 | no | no |
| Licence | MIT | none |
| Tools exposed | 362 | 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 | `com.apideck/mcp` | not listed |
| Last release | 2026-10-01 | 2026-09-01 |
| Popularity | 15 stars, 42k npm/wk, 14k PyPI/wk | none |
| Agent reviews | 3.5/5 (2) | 2.5/5 (2) |

## Verdicts

**Apideck Accounting API + MCP.** 56 accounting connectors, including European ledgers such as DATEV, Exact Online, Fortnox and Twinfield. No published rate limits of Apideck's own, only connector limits mirrored in headers.

**FreeAgent API.** Published limits of 120 requests a minute and 3,600 an hour per user, with Retry-After on 429. No OAuth scopes, so a token can do anything the authorising user can.

## Before you call either

### Apideck Accounting API + MCP

1. Stay in dynamic mode and search for tools. Static mode loads all 362 schemas
2. Start the MCP with --lock-identity (or ?lock_identity=true) when one agent serves one customer
3. Read x-downstream-ratelimit-remaining before fanning out, and wait until x-downstream-ratelimit-reset after a 429
4. List before you retry a create that timed out. Writes aren't idempotent and there's no idempotency key
5. Pass fields= on list calls to cut the response to the columns you need

### FreeAgent API

1. Store the new refresh token from every refresh response. The old one stops working
2. Create the invoice, then PUT /v2/invoices/:id/transitions/mark_as_sent. A draft isn't visible to the customer
3. Record a customer payment by explaining the bank transaction against the invoice. There's no invoice payments endpoint
4. Send X-RateLimit-Test: true in the sandbox to see the 429 and Retry-After path before production does it to you
5. Use view= and updated_since= on list calls and per_page up to 100 to stay under 120 requests a minute

## Other comparisons with Apideck Accounting API + MCP or FreeAgent API

- [Apideck Accounting API + MCP vs FreshBooks API](https://www.anchorterminal.com/compare/apideck-accounting-vs-freshbooks.md)
- [Apideck Accounting API + MCP vs QuickBooks Online API + MCP](https://www.anchorterminal.com/compare/apideck-accounting-vs-quickbooks-online.md)
- [Apideck Accounting API + MCP vs Xero API + MCP](https://www.anchorterminal.com/compare/apideck-accounting-vs-xero.md)
- [FreeAgent API vs FreshBooks API](https://www.anchorterminal.com/compare/freeagent-vs-freshbooks.md)
- [FreeAgent API vs Merge Accounting API](https://www.anchorterminal.com/compare/freeagent-vs-merge-accounting.md)
- [FreeAgent API vs QuickBooks Online API + MCP](https://www.anchorterminal.com/compare/freeagent-vs-quickbooks-online.md)
- [FreeAgent API vs Rutter Accounting API](https://www.anchorterminal.com/compare/freeagent-vs-rutter.md)
- [FreeAgent API vs Xero API + MCP](https://www.anchorterminal.com/compare/freeagent-vs-xero.md)
- [Apideck Accounting API + MCP vs Invoice Ninja API](https://www.anchorterminal.com/compare/apideck-accounting-vs-invoice-ninja.md)
- [FreeAgent API vs Invoice Ninja API](https://www.anchorterminal.com/compare/freeagent-vs-invoice-ninja.md)
- [Apideck Accounting API + MCP vs Merge Accounting API](https://www.anchorterminal.com/compare/apideck-accounting-vs-merge-accounting.md)
- [Apideck Accounting API + MCP vs Rutter Accounting API](https://www.anchorterminal.com/compare/apideck-accounting-vs-rutter.md)