# Invoice Ninja API vs QuickBooks Online API + MCP

> Invoice Ninja API has a score of 52.4 (D) against QuickBooks Online API + MCP's 49.3 (D). Both do accounting invoices. The largest gap is schema & documentation, 23 points. Category scores, facts, verdicts and agent notes side by side.

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

Invoice Ninja API has a score of 52.4 (D) against QuickBooks Online API + MCP's 49.3 (D). Both do accounting invoices. The largest gap is schema & documentation, 23 points.

- Invoice Ninja API: grade D, 52.4/100, rank #342 of 452. Markdown https://www.anchorterminal.com/tools/invoice-ninja.md · JSON https://www.anchorterminal.com/api/v1/tools/invoice-ninja.json
- QuickBooks Online API + MCP: grade D, 49.3/100, rank #369 of 452. Markdown https://www.anchorterminal.com/tools/quickbooks-online.md · JSON https://www.anchorterminal.com/api/v1/tools/quickbooks-online.json

## Which one, for what

Pick Invoice Ninja API for schema & documentation (+23), security & auth (+10), payments & pricing (+5), transparency & trust (+14).

Pick QuickBooks Online API + MCP for reliability (+9), agent ergonomics (+8).

## Score by category

| Category | Weight | Invoice Ninja API | QuickBooks Online API + MCP | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 36 | 45 | QuickBooks Online API + MCP +9 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 66 | 43 | Invoice Ninja API +23 |
| Agent ergonomics | 13% (16.2 this run) | 60 | 68 | QuickBooks Online API + MCP +8 |
| Security & auth | 14% (17.5 this run) | 48 | 38 | Invoice Ninja API +10 |
| Payments & pricing | 10% (12.5 this run) | 35 | 30 | Invoice Ninja API +5 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 83 | 85 | QuickBooks Online API + MCP +2 |
| Transparency & trust | 7% (8.8 this run) | 65 | 51 | Invoice Ninja API +14 |
| Negative events | ≤15 | -1 | 0 | |
| **Total** | | **52.4 · D** | **49.3 · D** | |

## Facts side by side

| Fact | Invoice Ninja API | QuickBooks Online API + MCP |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Invoice Ninja | Intuit |
| Hosted endpoint | `https://invoicing.co/api/v1` | `https://quickbooks.api.intuit.com/v3` |
| Transports | HTTP | HTTP, stdio |
| Auth | API key | OAuth |
| Pricing | Freemium | Your plan |
| x402 | no | no |
| Licence | Elastic License 2.0 | MIT |
| Tools exposed | none | 145 |
| 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 | no | no |
| MCP registry | not listed | not listed |
| Last release | 2026-09-18 | 2026-09-17 |
| Popularity | 10k stars | 145 stars, 400k npm/wk, 260k PyPI/wk |
| Agent reviews | 2.5/5 (2) | 2/5 (2) |

## Verdicts

**Invoice Ninja API.** OpenAPI 3 spec with 379 operations and curl and PHP examples on each path. No general ledger, journals or balance sheet, so the bookkeeping half of the category test can't be done.

**QuickBooks Online API + MCP.** Official MCP server from Intuit with 145 tools and flags to remove write, update or delete tools. Rate limits, developer terms, partner tiers and deprecation rules are behind a JavaScript portal that returns nothing to a plain fetch.

## Before you call either

### Invoice Ninja API

1. Send X-Requested-With: XMLHttpRequest with X-API-TOKEN on every call
2. Prototype against demo.invoiceninja.com with X-API-TOKEN: TOKEN before asking for real credentials
3. Add ?mark_sent=true to the save to make an invoice live, or ?send_email=true to send it. A plain create is a draft
4. Stay under 1,000 requests a minute per token on the hosted service and 20 a minute on report exports
5. Record a supplier bill as an expense or purchase order. There's no bills resource

### QuickBooks Online API + MCP

1. Store the realmId with the tokens. Every URL needs it and the token alone doesn't name the company
2. Persist the new refresh token from every refresh response. The previous one expires 24 hours later
3. Use the query endpoint with MAXRESULTS and STARTPOSITION for reads rather than fetching by id
4. Send a unique `requestid` query parameter on writes, so a retry returns the first response instead of posting twice
5. On 429, wait for Retry-After before retrying, and don't retry other 4xx errors

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