Head to head · Tax calculate · October 2026 research run
Anrok vs Fonoa
Anrok scores 61.6 (C) on agent readiness against Fonoa's 51.7 (D), and leads in 6 of 7 scored categories. Both do tax calculate.
Which one, for what
Anrok C
Good for An agent working for a software or ecommerce seller that already uses Anrok and wants calculation, exemption certificates and filing status in one account.
Ahead on
- Reliability, 88 against 66
- Agent ergonomics, 70 against 64
- Security & auth, 59 against 47
- Payments & pricing, 15 against 3
- Transparency & trust, 54 against 48
Watch for
No self-serve signup. Starter is $100 per market a month through "Talk to us", and Custom is quoted by sales
Fonoa D
Good for An agent working for a company that already has a Fonoa contract and needs tax ID validation, VAT or GST calculation, or e-invoice reporting across many countries through one API.
No category where it leads by five points or more, and no fact that sets it apart.
Watch for
No self-serve signup. Sandbox, demo and production keys are issued by Fonoa after contact by email or the sales form
Score by category
| Category | Weight this run | Anrok | Fonoa | Edge |
|---|---|---|---|---|
| Reliability | 16%20 | 88 | 66 | Anrok +22 |
| Performance | 10%pending | pending | pending | not scored in this run |
| Schema & documentation | 13%16.2 | 71 | 68 | Anrok +3 |
| Agent ergonomics | 13%16.2 | 70 | 64 | Anrok +6 |
| Security & auth | 14%17.5 | 59 | 47 | Anrok +12 |
| Payments & pricing | 10%12.5 | 15 | 3 | Anrok +12 |
| Task success | 10%pending | pending | pending | not scored in this run |
| Maintenance & community | 7%8.8 | 47 | 49 | Fonoa +2 |
| Transparency & trust | 7%8.8 | 54 | 48 | Anrok +6 |
| Negative events | ≤15 | 0 | 0 | |
| Total | 61.6 · C | 51.7 · D |
Facts side by side
| Fact | Anrok | Fonoa |
|---|---|---|
| Kind | HTTP API | HTTP API |
| Vendor | Anrok, Inc. | Fonoa Technologies Limited |
| Hosted endpoint | https://api.anrok.com | https://api.fonoa.com |
| Transports | HTTP, Streamable HTTP | HTTP |
| Auth | OAuth or key | API key |
| Pricing | Paid | Paid |
| x402 | no | no |
| Licence | Proprietary service under the Anrok SaaS Services Agreement. The OpenAPI file states "All rights reserved" | Proprietary service. The API contract is not published. The public Terms of Service took effect on 14 May 2020 and name older seller sites |
| Tools exposed | 31 | none |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-10-06 | 2026-10-02 |
| Terms last updated | 2026-07-01 | no document linked |
| Privacy policy last updated | 2026-07-01 | no date given |
| Customer content may train models | not found in the text | |
| Terms restrict automated access | yes | |
| Terms restrict benchmarking | yes | |
| Terms or service can change without notice | not found in the text | |
| Arbitration or class-action waiver | not found in the text |
Verdicts
Anrok
The public OpenAPI 3.1 spec covers 26 operations with typed error codes, and the remote MCP server uses OAuth 2.1 with six scopes and keeps voids, refunds and filing approval away from the model. Access needs a seller account arranged through sales, API keys carry no scopes, and no API changelog, SDK or subprocessor list was found.
Fonoa
The API reference is served as Markdown with an OpenAPI definition on each endpoint page, and e-invoicing submissions are idempotent by transaction_id. API keys are issued by Fonoa staff after contact, no price, rate limit or changelog is published, and the only public terms date from May 2020 and cover older seller sites.
Before you call either
Anrok
- Send every call as a POST with a JSON body to https://api.anrok.com, including reads such as /v1/seller/products/list
- Call createEphemeral for a quote and createOrUpdate only when the invoice is final. createOrUpdate saves the transaction for filing
- Reuse the same transaction id on a retry. createOrUpdate overwrites by id, so a repeat doesn't create a second record
- Expect transactionFrozenForFiling once a transaction is on a filed return. Negate it with createNegation and write a new id with a suffix such as :s2
- On 429 wait the number of seconds in Retry-After. The default limit is 10 requests a second per seller account
Fonoa
- Send the key in the
Ocp-Apim-Subscription-Keyheader. Use the sandbox key at https://sandbox.fonoa.com and the production key at https://api.fonoa.com - Treat validations and e-invoicing submissions as asynchronous. POST, then poll the GET endpoint or wait for the webhook, and avoid tight polling
- Reuse the same
transaction_idon a retry of/v1/transactions. A transaction already processed is not processed again - Commit a calculation with POST
/tax/v2/calculations/<uuid>/commitonly when the sale is final. The commit adds it to revenue tracking - Ask the Fonoa contact to configure webhooks. There is no API for it, and always fetch
resource_urlas given in the webhook
Questions
Which is better for AI agents, Anrok or Fonoa?
Anrok scores 61.6 (C) on agent readiness against Fonoa's 51.7 (D), and leads in 6 of 7 scored categories.
Do Anrok and Fonoa need an API key?
Anrok takes an API key or an OAuth sign-in. Fonoa needs an API key.
Can an agent call Anrok and Fonoa without installing anything?
Yes. Anrok has a hosted endpoint at https://api.anrok.com and Fonoa at https://api.fonoa.com.
Other comparisons with Anrok or Fonoa
Machine-readable
- This page as Markdown
/compare/anrok-vs-fonoa.md· slim.min.md· JSON.json(or sendAccept: text/markdown) - Each listing in full
/api/v1/tools/anrok.json·/api/v1/tools/fonoa.json - From a terminal
anchor compare anrok fonoa(the CLI) - Over MCP
compare_tools {"a": "anrok", "b": "fonoa"}at/mcp, no key