# Kintsugi vs Numeral

> Kintsugi scores 60.7 (C) on agent readiness against Numeral's 49.3 (D), and leads in 6 of 7 scored categories. Both do tax calculate. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/kintsugi-vs-numeral
- Markdown: https://www.anchorterminal.com/compare/kintsugi-vs-numeral.md (~2,250 tokens)
- Slim: https://www.anchorterminal.com/compare/kintsugi-vs-numeral.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/kintsugi-vs-numeral.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

Kintsugi scores 60.7 (C) on agent readiness against Numeral's 49.3 (D), and leads in 6 of 7 scored categories. Both do tax calculate.

- Kintsugi: grade C, 60.7/100, rank #392 of 722. Markdown https://www.anchorterminal.com/tools/kintsugi.md · JSON https://www.anchorterminal.com/api/v1/tools/kintsugi.json
- Numeral: grade D, 49.3/100, rank #611 of 722. Markdown https://www.anchorterminal.com/tools/numeral.md · JSON https://www.anchorterminal.com/api/v1/tools/numeral.json

## Which one, for what

### Kintsugi (C)

Good for: An agent working for a seller that already has Kintsugi Premium and wants estimates, transaction sync, exemptions, nexus, registrations and filing status through one API, or read-only answers about an account through the OAuth MCP server.

Ahead on:
- Reliability, 73 against 25
- Security & auth, 52 against 47
- Maintenance & community, 78 against 60
- Transparency & trust, 60 against 45

Watch for: API access, SDKs and real-time tax calculation are listed only under Premium, which is priced on request. API keys need a paid plan that includes them

### Numeral (D)

Good for: An agent working for a seller or platform that has a Numeral account and needs tax at checkout, committed transactions for filing, and read access to nexus, registrations and filings through MCP.

Also in its favour:
- No incidents deducted, where Kintsugi loses 3 points for them

Watch for: No status page, uptime SLA or numeric rate limit was found. The product page says rate limits can be removed on request


## Score by category

| Category | Weight | Kintsugi | Numeral | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 73 | 25 | Kintsugi +48 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 87 | 87 | even |
| Agent ergonomics | 13% (16.2 this run) | 75 | 71 | Kintsugi +4 |
| Security & auth | 14% (17.5 this run) | 52 | 47 | Kintsugi +5 |
| Payments & pricing | 10% (12.5 this run) | 13 | 10 | Kintsugi +3 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 78 | 60 | Kintsugi +18 |
| Transparency & trust | 7% (8.8 this run) | 60 | 45 | Kintsugi +15 |
| Negative events | ≤15 | -3 | 0 | |
| **Total** | | **60.7 · C** | **49.3 · D** | |

## Facts side by side

| Fact | Kintsugi | Numeral |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Kintsugi AI, Inc. | Numeral Two, Inc. |
| Hosted endpoint | `https://api.trykintsugi.com` | `https://api.numeralhq.com` |
| Transports | HTTP, Streamable HTTP | HTTP, Streamable HTTP |
| Auth | OAuth or key | API key |
| Pricing | Paid | Paid |
| x402 | no | no |
| Licence | Proprietary service under the Kintsugi Terms of Service. The Python SDK repository is MIT | Proprietary service under Numeral's terms of service. The Go, Python and Node SDKs are Apache-2.0 |
| Tools exposed | 55 | 14 |
| Read-only variant documented | yes | yes |
| llms.txt | yes | yes |
| Last release | 2026-10-07 | 2026-09-15 |
| Terms last updated | 2026-09-29 | no date given |
| Privacy policy last updated | 2025-04-13 | no document linked |
| Customer content may train models | yes | not found in the text |
| Terms restrict automated access | yes | 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 | not found in the text |
| Arbitration or class-action waiver | yes | yes |
| Popularity | 71 npm/wk, 10 PyPI/wk | 0 stars, 9 npm/wk, 19 PyPI/wk |

## Verdicts

**Kintsugi.** The docs are built for machine readers, with llms.txt, Markdown pages, a public OpenAPI 3.1 file, a dated changelog and an MCP server whose 55 tools carry read-only and destructive annotations. API keys need the custom-priced Premium plan and carry no scopes, no general rate limit is published, and breaking changes reached the pinned 2026-07-21 release in October 2026.

**Numeral.** Docs are written for agents, with a public OpenAPI spec for 32 operations, Markdown pages, llms.txt and a remote MCP server whose 14 tools are read-only by default. No status page, numeric rate limit or SLA was found, the API ignores idempotency keys, and API access is sold on a custom plan after a demo.

## Before you call either

### Kintsugi

1. Send `Api-Key` and pin `Api-Version` (for example `2026-10-06`) on Tenanted API calls to `https://api.trykintsugi.com`. Without the header a request runs against `2026-07-21`
2. Use `x-api-key` and `x-organization-id` with `/v1` paths for the SDKs and the docs MCP server. They don't cover the Tenanted API
3. Call `POST /tax-estimations` for a quote. Nothing is stored. Record the sale with a transaction create, which answers 202, then check `processingStatus` before reading tax totals
4. Always send `externalId` on creates. A repeat with the same `externalId` and `source` returns the stored record with 200 and doesn't apply the new fields
5. Branch on the error `code`, not the message. Retry 429, 500 and 503 with exponential backoff, and restart paging from the first page on `stale_cursor`

### Numeral

1. Send `X-API-Version: 2026-03-01` on every call to `https://api.numeralhq.com`. Merchant, platform and certificate endpoints reject requests without it
2. Commit with a stable `reference_order_id`. On `REFERENCE_ORDER_ID_ALREADY_EXISTS` look up the existing transaction, because `Idempotency-Key` is ignored
3. Commit before the calculation's `expires_at`. If it has expired, calculate again and commit the new `calculation_id` with the original `reference_order_id`
4. Send `amount` as the line total in minor units to `/tax/calculations` and as the per-unit price to `/tax/platform/calculations`
5. Start with an `sk_test_` key. Certificate endpoints and MCP certificate tools are live only and answer `TESTMODE_NOT_SUPPORTED` or `live_mode_required`

## Questions

### Which is better for AI agents, Kintsugi or Numeral?

Kintsugi scores 60.7 (C) on agent readiness against Numeral's 49.3 (D), and leads in 6 of 7 scored categories.

### Do Kintsugi and Numeral need an API key?

Kintsugi takes an API key or an OAuth sign-in. Numeral needs an API key.

### Can an agent call Kintsugi and Numeral without installing anything?

Yes. Kintsugi has a hosted endpoint at https://api.trykintsugi.com and Numeral at https://api.numeralhq.com.


## For agents

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

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