{
  "data": {
    "a": {
      "slug": "fonoa",
      "name": "Fonoa",
      "vendor": "Fonoa Technologies Limited",
      "vendorUrl": "https://www.fonoa.com",
      "kind": "http-api",
      "category": "tax",
      "summary": "Fonoa is a hosted indirect tax platform for VAT, GST and sales tax. Its REST API validates tax identification numbers, calculates tax on a transaction and reports e-invoices to tax authorities, with a sandbox and a demo environment.",
      "url": "https://www.anchorterminal.com/tools/fonoa",
      "markdownUrl": "https://www.anchorterminal.com/tools/fonoa.md",
      "slimMarkdownUrl": "https://www.anchorterminal.com/tools/fonoa.min.md",
      "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/fonoa.json",
      "license": "Proprietary service. The API contract is not published. The public Terms of Service took effect on 14 May 2020 and name older seller sites",
      "transports": [
        "http"
      ],
      "remoteUrl": "https://api.fonoa.com",
      "packages": [],
      "auth": "api-key",
      "authNotes": "Every request needs a subscription key in the `Ocp-Apim-Subscription-Key` header. Fonoa issues a primary and a secondary key once a client is onboarded, on request by email or through the sales form, with separate keys for the sandbox and production. No self-serve key page, scopes, read-only keys or expiry were found in the docs. Countries are enabled per tenant, and a call for a country that is not enabled returns `COUNTRIES_NOT_ALLOWED`. Webhooks are set up by asking a Fonoa contact.",
      "pricing": "paid",
      "pricingNotes": "No public prices. www.fonoa.com/pricing returns 404 and the site's buttons read \"Get in touch\". No free tier or self-serve trial was found. The sandbox has unlimited usage with fixed data and the demo environment has limited usage, and a key for either comes from Fonoa after contact (https://docs.fonoa.com/reference/environments, checked 2026-10-08).",
      "priceSummary": "Paid",
      "where": "hosted",
      "x402": {
        "level": "no",
        "evidence": "No x402, MPP or L402 in the API docs, the OpenAPI definitions or the website (checked 2026-10-08).",
        "endpoints": []
      },
      "toolCount": null,
      "popularity": {
        "githubStars": null,
        "npmWeekly": null,
        "pypiWeekly": null,
        "asOf": "2026-10-08"
      },
      "docsUrl": "https://docs.fonoa.com",
      "llmsTxt": "https://docs.fonoa.com/llms.txt",
      "capabilities": [
        "tax.calculate",
        "tax.transactions",
        "tax.invoicing"
      ],
      "tags": [
        "hosted",
        "paid",
        "closed-source",
        "api-key",
        "openapi",
        "llms-txt",
        "sandbox",
        "webhooks",
        "sales-led",
        "status-page",
        "iso27001"
      ],
      "lastRelease": "2026-10-02",
      "graded": true,
      "anchor": {
        "graded": true,
        "score": 51.7,
        "grade": "D",
        "agentReady": false,
        "rank": 575,
        "ranked": true,
        "rankOf": 722,
        "categoryRank": 8,
        "methodology": "0.4",
        "run": "2026-10-01",
        "scores": {
          "ergonomics": 64,
          "maintenance": 49,
          "payments": 3,
          "reliability": 66,
          "schema": 68,
          "security": 47,
          "transparency": 48
        },
        "pending": [
          "performance",
          "tasks"
        ],
        "assessment": {
          "confidence": "medium",
          "date": "2026-10-08"
        },
        "negative": 0,
        "verdict": "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.",
        "bestFor": "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.",
        "strengths": [
          "Every reference page is served as Markdown with its OpenAPI 3.0 definition inline, indexed by docs.fonoa.com/llms.txt",
          "E-invoicing submissions are idempotent by `transaction_id`, and the docs say a transaction can be replayed any number of times",
          "The sandbox at sandbox.fonoa.com returns fixed outcomes for documented test inputs, including errors, delays and HTTP 500",
          "Webhooks carry a signed OIDC token with a SHA-256 checksum of the body, valid for one hour",
          "status.fonoa.com shows 100 per cent over 90 days for its E-Invoicing, Lookup and Tax monitors on 8 October 2026"
        ],
        "weaknesses": [
          "No self-serve signup. Sandbox, demo and production keys are issued by Fonoa after contact by email or the sales form",
          "No pricing page. www.fonoa.com/pricing returns 404 and the site's buttons read \"Get in touch\"",
          "No rate limit numbers found. The 429 response says \"Try again a bit later\" with no `Retry-After` documented",
          "No changelog, deprecation policy, official SDK or MCP server found. docs.fonoa.com/changelog returns 404",
          "The only public terms took effect on 14 May 2020 and cover older seller sites. They bar benchmarking and automated access without written permission"
        ],
        "agentNotes": [
          "Send the key in the `Ocp-Apim-Subscription-Key` header. 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_id` on a retry of `/v1/transactions`. A transaction already processed is not processed again",
          "Commit a calculation with POST `/tax/v2/calculations/\u003cuuid\u003e/commit` only 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_url` as given in the webhook"
        ],
        "metrics": {
          "kind": "remote",
          "measured": false
        },
        "reviewCount": 0,
        "avgRating": 0,
        "history": [
          {
            "basis": "public evidence",
            "confidence": "medium",
            "grade": "D",
            "methodology": "0.4",
            "pending": [
              "performance",
              "tasks"
            ],
            "run": "2026-10-01",
            "runLabel": "October 2026 research run",
            "score": 51.7
          }
        ],
        "editorialScores": {
          "ergonomics": 64,
          "maintenance": 49,
          "payments": 3,
          "reliability": 66,
          "schema": 68,
          "security": 47,
          "transparency": 27
        },
        "provenanceScore": 69
      },
      "connect": {
        "http": "curl --location 'https://sandbox.fonoa.com/lookup/v2/single-validations' \\\n--header 'Content-Type: application/json' \\\n--header 'Ocp-Apim-Subscription-Key: \u003cyour-sandbox-API-key\u003e' \\\n--data '{\n    \"country_iso_code\": \"pl\",\n    \"tax_identification_number\": \"2000\"\n}'"
      },
      "letme": {
        "capability": "https://letme.dev/tax.calculate",
        "tool": "https://letme.dev/fonoa"
      },
      "area": "domain-data",
      "provenance": {
        "legalEntity": "Fonoa Technologies Limited",
        "domain": "fonoa.com",
        "domainRegistered": "2004-08-24",
        "endpointOnVendorDomain": true,
        "terms": "",
        "privacy": "https://www.fonoa.com/legal/privacy-notice",
        "statusPage": "https://status.fonoa.com",
        "changelog": "",
        "securityTxt": "none",
        "checked": "2026-10-08",
        "notes": [
          "The privacy notice names Fonoa Technologies Limited, 6th Floor, South Bank House, Barrow Street, Dublin 4, Ireland as data controller. The site footer gives Irish company number 677236.",
          "No terms URL is recorded. The only terms Fonoa publishes, at www.fonoa.com/legal/terms-of-service, took effect on 14 May 2020, apply to fonoatech.com, efacturacion.net, efiscal.biz, portugal.fonoatech.com and efatture.net, name Fonoa Technologies ltd. and are governed by Croatian law. No service agreement or API terms for fonoa.com customers were found.",
          "The privacy notice says it does not apply to personal data Fonoa processes on behalf of customers using its software, where Fonoa is a processor under the customer's contract. No date of last update was found on the page.",
          "The API answers at api.fonoa.com, sandbox.fonoa.com and api-demo.fonoa.com, all on the vendor's domain.",
          "www.fonoa.com/.well-known/security.txt and www.fonoa.com/security.txt return 404. The security page describes a vulnerability disclosure programme with an email address.",
          "No changelog was found. docs.fonoa.com/changelog returns 404, and product news is published as blog posts.",
          "RDAP for fonoa.com gives a registration date of 2004-08-24."
        ],
        "score": 69
      },
      "pageJsonUrl": "https://www.anchorterminal.com/tools/fonoa.json",
      "live": {
        "slug": "fonoa",
        "probe": {
          "target": "https://api.fonoa.com",
          "method": "get",
          "lastAt": "2026-10-08T21:53:22.577198926Z",
          "lastOk": true,
          "lastStatus": 404,
          "lastMs": 68,
          "authRequired": false,
          "uptime24h": 100,
          "uptime30d": 100,
          "p50ms24h": 81,
          "p95ms24h": 161,
          "samples24h": 28,
          "samples30d": 28,
          "days": [
            {
              "date": "2026-10-08",
              "probes": 28,
              "ok": 28
            }
          ]
        },
        "vendorStatus": {
          "page": "https://status.fonoa.com",
          "indicator": "unknown",
          "summary": "no machine-readable status found",
          "checkedAt": "2026-10-08T19:38:33.601208747Z"
        },
        "updatedAt": "2026-10-08T21:53:22.577198926Z"
      }
    },
    "answer": "Vertex O Series scores 54.7 (C) on agent readiness against Fonoa's 51.7 (D), and leads in 4 of 7 scored categories. Fonoa leads on agent ergonomics.",
    "b": {
      "slug": "vertex-tax",
      "name": "Vertex O Series",
      "vendor": "Vertex, Inc.",
      "vendorUrl": "https://www.vertexinc.com",
      "kind": "http-api",
      "category": "tax",
      "summary": "Vertex O Series is indirect tax software from Vertex, Inc. that calculates sales tax, use tax and VAT for a transaction and records it for reporting. Agents reach it through REST v2 APIs with OAuth client credentials.",
      "url": "https://www.anchorterminal.com/tools/vertex-tax",
      "markdownUrl": "https://www.anchorterminal.com/tools/vertex-tax.md",
      "slimMarkdownUrl": "https://www.anchorterminal.com/tools/vertex-tax.min.md",
      "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/vertex-tax.json",
      "license": "Proprietary service under a customer agreement with Vertex, Inc. that isn't published",
      "transports": [
        "http"
      ],
      "remoteUrl": "https://calcconnect.vertexsmb.com/vertex-ws/v2",
      "packages": [],
      "auth": "oauth",
      "authNotes": "Access is granted through a sales contract. OAuth 2.0 client credentials follow. A Cloud Partition System Administrator creates an API credential under Account Settings, Security \u0026 Credentials, choosing the API and the partition it maps to. The client id and secret are exchanged at https://auth.vertexcloud.com/oauth/token with audience `verx://migration-api` for a bearer token that lasts 3,599 seconds. The secret is shown once and a credential can't be edited. Token requests are limited to 10 per 8 hours, and a caching endpoint at tokenguard.vertexcloud.com returns unexpired tokens. On-Premise and On-Demand deployments use a service account with the API User role and their own token URL.",
      "pricing": "paid",
      "pricingNotes": "No public prices. www.vertexinc.com/pricing returns 404 and the O Series product page asks visitors to book a demo. No free tier, trial or self-serve sandbox was found, and the security guide says to work with the Vertex sales team to establish an account. O Series Online Commerce documents a sandbox host that uses the same contracted credentials (checked 2026-10-08).",
      "priceSummary": "Paid",
      "where": "hosted",
      "x402": {
        "level": "no",
        "evidence": "No x402, MPP or L402 in the developer docs or the OpenAPI specs (checked 2026-10-08).",
        "endpoints": []
      },
      "toolCount": null,
      "popularity": {
        "githubStars": null,
        "npmWeekly": null,
        "pypiWeekly": null,
        "asOf": "2026-10-08"
      },
      "docsUrl": "https://developer.vertexinc.com/oseries/docs/quick-start",
      "openapi": "https://developer.vertexinc.com/oseries/openapi/vertex-tax-calculation-and-tax-gis-api.json",
      "capabilities": [
        "tax.calculate",
        "tax.transactions",
        "tax.exemptions",
        "tax.invoicing"
      ],
      "tags": [
        "hosted",
        "enterprise",
        "oauth",
        "openapi",
        "sales-led",
        "status-page",
        "soc2",
        "on-premise",
        "vat",
        "sales-tax"
      ],
      "lastRelease": "2026-09-25",
      "graded": true,
      "anchor": {
        "graded": true,
        "score": 54.7,
        "grade": "C",
        "agentReady": false,
        "rank": 526,
        "ranked": true,
        "rankOf": 722,
        "categoryRank": 7,
        "methodology": "0.4",
        "run": "2026-10-01",
        "scores": {
          "ergonomics": 51,
          "maintenance": 62,
          "payments": 0,
          "reliability": 65,
          "schema": 74,
          "security": 57,
          "transparency": 68
        },
        "pending": [
          "performance",
          "tasks"
        ],
        "assessment": {
          "confidence": "medium",
          "date": "2026-10-08"
        },
        "negative": 0,
        "verdict": "Public OpenAPI 3.0 specs cover calculation, transaction management, tax area lookup and tax configuration, and guides are served as Markdown. Access needs a sales contract. No price, free tier, sandbox signup, calculation rate limit, idempotency key or official SDK was found in the reviewed documentation.",
        "bestFor": "An agent working inside a company that already has an O Series licence, for quotes, invoice tax, tax area lookups and tax configuration across sales tax, use tax and VAT.",
        "strengths": [
          "OpenAPI 3.0 specs download without a login. Calculation and Tax GIS is version 2.9.0 with 14 operations, Tax Configuration v2.1.0 with 29",
          "Every guide page is served as Markdown when .md is added to its URL",
          "Each Cloud API credential maps to one API and one partition, and token requests carrying credentials in the URL are rejected",
          "status.vertexinc.com lists 26 components, and no incident from 10 July to 8 October 2026 names O Series Cloud",
          "The trust centre lists SOC 1 Type II and SOC 2 Type II reports for 2025 and five sub-processors with locations"
        ],
        "weaknesses": [
          "No public price, free tier or self-serve signup. The security guide sends new users to the Vertex sales team for an account",
          "No rate limit for the calculation API and no idempotency key were found in the reviewed documentation",
          "The standard token endpoint allows 10 access token requests per 8 hours for each client",
          "No official SDK, MCP server or llms.txt on the developer site was found",
          "The customer agreement, DPA and Service Level Exhibit sit behind an access request in the trust centre"
        ],
        "agentNotes": [
          "Cache the access token for its 3,599-second life. The standard token endpoint allows 10 requests per 8 hours, and tokenguard.vertexcloud.com returns a cached token",
          "Send no `Authorization: Bearer` header to /oauth/token, and put the client id and secret in the body or a Basic header. Credentials in the URL are rejected",
          "Set `saleMessageType` to QUOTATION for an estimate. INVOICE is stored for reporting and remittance",
          "Call GET /v2/transaction-exists/{transactionid} before retrying a failed INVOICE. No idempotency key is documented",
          "Delete, reverse or roll back a Cloud transaction within 90 days of calculation. Later requests can cause calculation errors or duplicates"
        ],
        "metrics": {
          "kind": "remote",
          "measured": false
        },
        "reviewCount": 0,
        "avgRating": 0,
        "history": [
          {
            "basis": "public evidence",
            "confidence": "medium",
            "grade": "C",
            "methodology": "0.4",
            "pending": [
              "performance",
              "tasks"
            ],
            "run": "2026-10-01",
            "runLabel": "October 2026 research run",
            "score": 54.7
          }
        ],
        "editorialScores": {
          "ergonomics": 51,
          "maintenance": 62,
          "payments": 0,
          "reliability": 65,
          "schema": 74,
          "security": 57,
          "transparency": 52
        },
        "provenanceScore": 84
      },
      "connect": {
        "http": "curl --location 'https://auth.vertexcloud.com/oauth/token' \\\n  --header 'Content-Type: application/x-www-form-urlencoded' \\\n  --data-urlencode 'client_id=\u003cyour-client-id\u003e' \\\n  --data-urlencode 'client_secret=\u003cyour-client-secret\u003e' \\\n  --data-urlencode 'audience=verx://migration-api' \\\n  --data-urlencode 'grant_type=client_credentials'"
      },
      "letme": {
        "capability": "https://letme.dev/tax.calculate",
        "tool": "https://letme.dev/vertex-tax"
      },
      "area": "domain-data",
      "provenance": {
        "legalEntity": "Vertex, Inc.",
        "domain": "vertexinc.com",
        "domainRegistered": "1998-09-01",
        "endpointOnVendorDomain": true,
        "terms": "https://www.vertexinc.com/terms-of-use",
        "privacy": "https://www.vertexinc.com/vertex-privacy-policy",
        "statusPage": "https://status.vertexinc.com",
        "changelog": "https://developer.vertexinc.com/oseries/docs/os-release",
        "securityTxt": "none",
        "checked": "2026-10-08",
        "notes": [
          "The website terms of use and the privacy notice name Vertex, Inc., 2301 Renaissance Blvd., King of Prussia, PA 19406, and the terms choose Pennsylvania law. The privacy notice was last updated on 19 August 2026.",
          "Cloud API calls go to calcconnect.vertexsmb.com and auth.vertexcloud.com, which the vendor's developer docs name as its hosts. We didn't check the registration of those two domains. On-Demand deployments answer on \u003ccustomer\u003e.ondemand.vertexinc.com.",
          "www.vertexinc.com/.well-known/security.txt and /security.txt return 404.",
          "The terms URL is the website terms of use. The customer agreement, DPA, Security Exhibit and Service Level Exhibit are listed in the trust centre behind an access request.",
          "RDAP for vertexinc.com gives a registration date of 1998-09-01."
        ],
        "score": 84
      },
      "pageJsonUrl": "https://www.anchorterminal.com/tools/vertex-tax.json",
      "live": {
        "slug": "vertex-tax",
        "probe": {
          "target": "https://calcconnect.vertexsmb.com/vertex-ws/v2",
          "method": "get",
          "lastAt": "2026-10-08T21:53:37.659165049Z",
          "lastOk": true,
          "lastStatus": 401,
          "lastMs": 332,
          "lastNote": "asks for credentials",
          "authRequired": true,
          "uptime24h": 100,
          "uptime30d": 100,
          "p50ms24h": 337,
          "p95ms24h": 399,
          "samples24h": 71,
          "samples30d": 71,
          "days": [
            {
              "date": "2026-10-08",
              "probes": 71,
              "ok": 71
            }
          ]
        },
        "vendorStatus": {
          "page": "https://status.vertexinc.com",
          "indicator": "none",
          "summary": "All Systems Operational",
          "checkedAt": "2026-10-08T21:58:17.542181507Z"
        },
        "securityTxt": {
          "url": "https://vertexinc.com/.well-known/security.txt",
          "state": "none",
          "checkedAt": "2026-10-08T15:38:42.909167355Z"
        },
        "pages": [
          {
            "url": "https://developer.vertexinc.com/oseries/docs/os-release",
            "kind": "changelog",
            "status": 200,
            "checkedAt": "2026-10-08T18:17:20.759088603Z",
            "changedAt": "0001-01-01T00:00:00Z",
            "fingerprint": "dbf33e43de24"
          },
          {
            "url": "https://www.vertexinc.com/vertex-privacy-policy",
            "kind": "privacy",
            "status": 200,
            "checkedAt": "2026-10-08T18:31:23.444238352Z",
            "changedAt": "0001-01-01T00:00:00Z",
            "fingerprint": "a77bfa05dfc0"
          },
          {
            "url": "https://www.vertexinc.com/terms-of-use",
            "kind": "terms",
            "status": 200,
            "checkedAt": "2026-10-08T18:31:21.326104819Z",
            "changedAt": "0001-01-01T00:00:00Z",
            "fingerprint": "8a38170a4aef"
          }
        ],
        "updatedAt": "2026-10-08T21:58:17.542181507Z"
      }
    },
    "facts": [
      {
        "a": "HTTP API",
        "b": "HTTP API",
        "name": "Kind"
      },
      {
        "a": "Fonoa Technologies Limited",
        "b": "Vertex, Inc.",
        "name": "Vendor"
      },
      {
        "a": "https://api.fonoa.com",
        "b": "https://calcconnect.vertexsmb.com/vertex-ws/v2",
        "name": "Hosted endpoint"
      },
      {
        "a": "HTTP",
        "b": "HTTP",
        "name": "Transports"
      },
      {
        "a": "API key",
        "b": "OAuth",
        "name": "Auth"
      },
      {
        "a": "Paid",
        "b": "Paid",
        "name": "Pricing"
      },
      {
        "a": "no",
        "b": "no",
        "name": "x402"
      },
      {
        "a": "Proprietary service. The API contract is not published. The public Terms of Service took effect on 14 May 2020 and name older seller sites",
        "b": "Proprietary service under a customer agreement with Vertex, Inc. that isn't published",
        "name": "Licence"
      },
      {
        "a": "no",
        "b": "no",
        "name": "Read-only variant documented"
      },
      {
        "a": "yes",
        "b": "no",
        "name": "llms.txt"
      },
      {
        "a": "2026-10-02",
        "b": "2026-09-25",
        "name": "Last release"
      },
      {
        "a": "no document linked",
        "b": "no date given",
        "name": "Terms last updated"
      },
      {
        "a": "no date given",
        "b": "no date given",
        "name": "Privacy policy last updated"
      },
      {
        "a": "",
        "b": "not found in the text",
        "name": "Customer content may train models"
      },
      {
        "a": "",
        "b": "not found in the text",
        "name": "Terms restrict automated access"
      },
      {
        "a": "",
        "b": "not found in the text",
        "name": "Terms restrict benchmarking"
      },
      {
        "a": "",
        "b": "not found in the text",
        "name": "Terms or service can change without notice"
      },
      {
        "a": "",
        "b": "not found in the text",
        "name": "Arbitration or class-action waiver"
      }
    ],
    "faq": [
      {
        "answer": "Vertex O Series scores 54.7 (C) on agent readiness against Fonoa's 51.7 (D), and leads in 4 of 7 scored categories. Fonoa leads on agent ergonomics.",
        "question": "Which is better for AI agents, Fonoa or Vertex O Series?"
      },
      {
        "answer": "Fonoa needs an API key. Vertex O Series uses an OAuth sign-in.",
        "question": "Do Fonoa and Vertex O Series need an API key?"
      },
      {
        "answer": "Yes. Fonoa has a hosted endpoint at https://api.fonoa.com and Vertex O Series at https://calcconnect.vertexsmb.com/vertex-ws/v2.",
        "question": "Can an agent call Fonoa and Vertex O Series without installing anything?"
      }
    ],
    "goodFor": [
      {
        "aheadOn": [
          "Agent ergonomics, 64 against 51"
        ],
        "also": null,
        "goodFor": "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.",
        "slug": "fonoa",
        "watchFor": "No self-serve signup. Sandbox, demo and production keys are issued by Fonoa after contact by email or the sales form"
      },
      {
        "aheadOn": [
          "Schema \u0026 documentation, 74 against 68",
          "Security \u0026 auth, 57 against 47",
          "Maintenance \u0026 community, 62 against 49",
          "Transparency \u0026 trust, 68 against 48"
        ],
        "also": null,
        "goodFor": "An agent working inside a company that already has an O Series licence, for quotes, invoice tax, tax area lookups and tax configuration across sales tax, use tax and VAT.",
        "slug": "vertex-tax",
        "watchFor": "No public price, free tier or self-serve signup. The security guide sends new users to the Vertex sales team for an account"
      }
    ],
    "job": {
      "capability": "tax.calculate",
      "name": "Tax calculate"
    },
    "others": [
      {
        "json": "https://www.anchorterminal.com/compare/anrok-vs-fonoa.json",
        "title": "Anrok vs Fonoa",
        "url": "https://www.anchorterminal.com/compare/anrok-vs-fonoa"
      },
      {
        "json": "https://www.anchorterminal.com/compare/anrok-vs-vertex-tax.json",
        "title": "Anrok vs Vertex O Series",
        "url": "https://www.anchorterminal.com/compare/anrok-vs-vertex-tax"
      },
      {
        "json": "https://www.anchorterminal.com/compare/avalara-vs-fonoa.json",
        "title": "Avalara AvaTax vs Fonoa",
        "url": "https://www.anchorterminal.com/compare/avalara-vs-fonoa"
      },
      {
        "json": "https://www.anchorterminal.com/compare/avalara-vs-vertex-tax.json",
        "title": "Avalara AvaTax vs Vertex O Series",
        "url": "https://www.anchorterminal.com/compare/avalara-vs-vertex-tax"
      },
      {
        "json": "https://www.anchorterminal.com/compare/fonoa-vs-kintsugi.json",
        "title": "Fonoa vs Kintsugi",
        "url": "https://www.anchorterminal.com/compare/fonoa-vs-kintsugi"
      },
      {
        "json": "https://www.anchorterminal.com/compare/fonoa-vs-numeral.json",
        "title": "Fonoa vs Numeral",
        "url": "https://www.anchorterminal.com/compare/fonoa-vs-numeral"
      },
      {
        "json": "https://www.anchorterminal.com/compare/fonoa-vs-quaderno.json",
        "title": "Fonoa vs Quaderno",
        "url": "https://www.anchorterminal.com/compare/fonoa-vs-quaderno"
      },
      {
        "json": "https://www.anchorterminal.com/compare/fonoa-vs-taxcloud.json",
        "title": "Fonoa vs TaxCloud",
        "url": "https://www.anchorterminal.com/compare/fonoa-vs-taxcloud"
      },
      {
        "json": "https://www.anchorterminal.com/compare/fonoa-vs-taxjar.json",
        "title": "Fonoa vs TaxJar",
        "url": "https://www.anchorterminal.com/compare/fonoa-vs-taxjar"
      },
      {
        "json": "https://www.anchorterminal.com/compare/fonoa-vs-zamp.json",
        "title": "Fonoa vs Zamp",
        "url": "https://www.anchorterminal.com/compare/fonoa-vs-zamp"
      },
      {
        "json": "https://www.anchorterminal.com/compare/kintsugi-vs-vertex-tax.json",
        "title": "Kintsugi vs Vertex O Series",
        "url": "https://www.anchorterminal.com/compare/kintsugi-vs-vertex-tax"
      },
      {
        "json": "https://www.anchorterminal.com/compare/numeral-vs-vertex-tax.json",
        "title": "Numeral vs Vertex O Series",
        "url": "https://www.anchorterminal.com/compare/numeral-vs-vertex-tax"
      },
      {
        "json": "https://www.anchorterminal.com/compare/quaderno-vs-vertex-tax.json",
        "title": "Quaderno vs Vertex O Series",
        "url": "https://www.anchorterminal.com/compare/quaderno-vs-vertex-tax"
      },
      {
        "json": "https://www.anchorterminal.com/compare/taxcloud-vs-vertex-tax.json",
        "title": "TaxCloud vs Vertex O Series",
        "url": "https://www.anchorterminal.com/compare/taxcloud-vs-vertex-tax"
      },
      {
        "json": "https://www.anchorterminal.com/compare/taxjar-vs-vertex-tax.json",
        "title": "TaxJar vs Vertex O Series",
        "url": "https://www.anchorterminal.com/compare/taxjar-vs-vertex-tax"
      },
      {
        "json": "https://www.anchorterminal.com/compare/vertex-tax-vs-zamp.json",
        "title": "Vertex O Series vs Zamp",
        "url": "https://www.anchorterminal.com/compare/vertex-tax-vs-zamp"
      }
    ],
    "scores": [
      {
        "by": 1,
        "edge": "fonoa",
        "fonoa": 66,
        "key": "reliability",
        "name": "Reliability",
        "vertex-tax": 65,
        "weight": 16
      },
      {
        "key": "performance",
        "name": "Performance",
        "pending": true,
        "weight": 10
      },
      {
        "by": 6,
        "edge": "vertex-tax",
        "fonoa": 68,
        "key": "schema",
        "name": "Schema \u0026 documentation",
        "vertex-tax": 74,
        "weight": 13
      },
      {
        "by": 13,
        "edge": "fonoa",
        "fonoa": 64,
        "key": "ergonomics",
        "name": "Agent ergonomics",
        "vertex-tax": 51,
        "weight": 13
      },
      {
        "by": 10,
        "edge": "vertex-tax",
        "fonoa": 47,
        "key": "security",
        "name": "Security \u0026 auth",
        "vertex-tax": 57,
        "weight": 14
      },
      {
        "by": 3,
        "edge": "fonoa",
        "fonoa": 3,
        "key": "payments",
        "name": "Payments \u0026 pricing",
        "vertex-tax": 0,
        "weight": 10
      },
      {
        "key": "tasks",
        "name": "Task success",
        "pending": true,
        "weight": 10
      },
      {
        "by": 13,
        "edge": "vertex-tax",
        "fonoa": 49,
        "key": "maintenance",
        "name": "Maintenance \u0026 community",
        "vertex-tax": 62,
        "weight": 7
      },
      {
        "by": 20,
        "edge": "vertex-tax",
        "fonoa": 48,
        "key": "transparency",
        "name": "Transparency \u0026 trust",
        "vertex-tax": 68,
        "weight": 7
      }
    ],
    "summary": "Vertex O Series scores 54.7 (C) on agent readiness against Fonoa's 51.7 (D), and leads in 4 of 7 scored categories. Fonoa leads on agent ergonomics. Both do tax calculate.",
    "verdicts": {
      "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.",
      "vertex-tax": "Public OpenAPI 3.0 specs cover calculation, transaction management, tax area lookup and tax configuration, and guides are served as Markdown. Access needs a sales contract. No price, free tier, sandbox signup, calculation rate limit, idempotency key or official SDK was found in the reviewed documentation."
    }
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  "markdown": "Vertex O Series scores 54.7 (C) on agent readiness against Fonoa's 51.7 (D), and leads in 4 of 7 scored categories. Fonoa leads on agent ergonomics. Both do tax calculate.\n\n- Fonoa: grade D, 51.7/100, rank #575 of 722. Markdown https://www.anchorterminal.com/tools/fonoa.md · JSON https://www.anchorterminal.com/api/v1/tools/fonoa.json\n- Vertex O Series: grade C, 54.7/100, rank #526 of 722. Markdown https://www.anchorterminal.com/tools/vertex-tax.md · JSON https://www.anchorterminal.com/api/v1/tools/vertex-tax.json\n\n## Which one, for what\n\n### Fonoa (D)\n\nGood 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.\n\nAhead on:\n- Agent ergonomics, 64 against 51\n\nWatch for: No self-serve signup. Sandbox, demo and production keys are issued by Fonoa after contact by email or the sales form\n\n### Vertex O Series (C)\n\nGood for: An agent working inside a company that already has an O Series licence, for quotes, invoice tax, tax area lookups and tax configuration across sales tax, use tax and VAT.\n\nAhead on:\n- Schema \u0026 documentation, 74 against 68\n- Security \u0026 auth, 57 against 47\n- Maintenance \u0026 community, 62 against 49\n- Transparency \u0026 trust, 68 against 48\n\nWatch for: No public price, free tier or self-serve signup. The security guide sends new users to the Vertex sales team for an account\n\n\n## Score by category\n\n| Category | Weight | Fonoa | Vertex O Series | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 66 | 65 | Fonoa +1 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 68 | 74 | Vertex O Series +6 |\n| Agent ergonomics | 13% (16.2 this run) | 64 | 51 | Fonoa +13 |\n| Security \u0026 auth | 14% (17.5 this run) | 47 | 57 | Vertex O Series +10 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 3 | 0 | Fonoa +3 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 49 | 62 | Vertex O Series +13 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 48 | 68 | Vertex O Series +20 |\n| Negative events | ≤15 | 0 | 0 | |\n| **Total** | | **51.7 · D** | **54.7 · C** | |\n\n## Facts side by side\n\n| Fact | Fonoa | Vertex O Series |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | Fonoa Technologies Limited | Vertex, Inc. |\n| Hosted endpoint | `https://api.fonoa.com` | `https://calcconnect.vertexsmb.com/vertex-ws/v2` |\n| Transports | HTTP | HTTP |\n| Auth | API key | OAuth |\n| Pricing | Paid | Paid |\n| x402 | no | no |\n| Licence | Proprietary service. The API contract is not published. The public Terms of Service took effect on 14 May 2020 and name older seller sites | Proprietary service under a customer agreement with Vertex, Inc. that isn't published |\n| Read-only variant documented | no | no |\n| llms.txt | yes | no |\n| Last release | 2026-10-02 | 2026-09-25 |\n| Terms last updated | no document linked | no date given |\n| Privacy policy last updated | no date given | no date given |\n| Customer content may train models |  | not found in the text |\n| Terms restrict automated access |  | not found in the text |\n| Terms restrict benchmarking |  | not found in the text |\n| Terms or service can change without notice |  | not found in the text |\n| Arbitration or class-action waiver |  | not found in the text |\n\n## Verdicts\n\n**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.\n\n**Vertex O Series.** Public OpenAPI 3.0 specs cover calculation, transaction management, tax area lookup and tax configuration, and guides are served as Markdown. Access needs a sales contract. No price, free tier, sandbox signup, calculation rate limit, idempotency key or official SDK was found in the reviewed documentation.\n\n## Before you call either\n\n### Fonoa\n\n1. Send the key in the `Ocp-Apim-Subscription-Key` header. Use the sandbox key at https://sandbox.fonoa.com and the production key at https://api.fonoa.com\n2. Treat validations and e-invoicing submissions as asynchronous. POST, then poll the GET endpoint or wait for the webhook, and avoid tight polling\n3. Reuse the same `transaction_id` on a retry of `/v1/transactions`. A transaction already processed is not processed again\n4. Commit a calculation with POST `/tax/v2/calculations/\u003cuuid\u003e/commit` only when the sale is final. The commit adds it to revenue tracking\n5. Ask the Fonoa contact to configure webhooks. There is no API for it, and always fetch `resource_url` as given in the webhook\n\n### Vertex O Series\n\n1. Cache the access token for its 3,599-second life. The standard token endpoint allows 10 requests per 8 hours, and tokenguard.vertexcloud.com returns a cached token\n2. Send no `Authorization: Bearer` header to /oauth/token, and put the client id and secret in the body or a Basic header. Credentials in the URL are rejected\n3. Set `saleMessageType` to QUOTATION for an estimate. INVOICE is stored for reporting and remittance\n4. Call GET /v2/transaction-exists/{transactionid} before retrying a failed INVOICE. No idempotency key is documented\n5. Delete, reverse or roll back a Cloud transaction within 90 days of calculation. Later requests can cause calculation errors or duplicates\n\n## Questions\n\n### Which is better for AI agents, Fonoa or Vertex O Series?\n\nVertex O Series scores 54.7 (C) on agent readiness against Fonoa's 51.7 (D), and leads in 4 of 7 scored categories. Fonoa leads on agent ergonomics.\n\n### Do Fonoa and Vertex O Series need an API key?\n\nFonoa needs an API key. Vertex O Series uses an OAuth sign-in.\n\n### Can an agent call Fonoa and Vertex O Series without installing anything?\n\nYes. Fonoa has a hosted endpoint at https://api.fonoa.com and Vertex O Series at https://calcconnect.vertexsmb.com/vertex-ws/v2.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/fonoa-vs-vertex-tax.json, and with the fewest tokens: https://www.anchorterminal.com/compare/fonoa-vs-vertex-tax.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"fonoa\", \"b\": \"vertex-tax\"}`. From a terminal: `anchor compare fonoa vertex-tax`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/fonoa.json and https://www.anchorterminal.com/api/v1/tools/vertex-tax.json\n\n## Other comparisons with Fonoa or Vertex O Series\n\n- [Anrok vs Fonoa](https://www.anchorterminal.com/compare/anrok-vs-fonoa.md)\n- [Anrok vs Vertex O Series](https://www.anchorterminal.com/compare/anrok-vs-vertex-tax.md)\n- [Avalara AvaTax vs Fonoa](https://www.anchorterminal.com/compare/avalara-vs-fonoa.md)\n- [Avalara AvaTax vs Vertex O Series](https://www.anchorterminal.com/compare/avalara-vs-vertex-tax.md)\n- [Fonoa vs Kintsugi](https://www.anchorterminal.com/compare/fonoa-vs-kintsugi.md)\n- [Fonoa vs Numeral](https://www.anchorterminal.com/compare/fonoa-vs-numeral.md)\n- [Fonoa vs Quaderno](https://www.anchorterminal.com/compare/fonoa-vs-quaderno.md)\n- [Fonoa vs TaxCloud](https://www.anchorterminal.com/compare/fonoa-vs-taxcloud.md)\n- [Fonoa vs TaxJar](https://www.anchorterminal.com/compare/fonoa-vs-taxjar.md)\n- [Fonoa vs Zamp](https://www.anchorterminal.com/compare/fonoa-vs-zamp.md)\n- [Kintsugi vs Vertex O Series](https://www.anchorterminal.com/compare/kintsugi-vs-vertex-tax.md)\n- [Numeral vs Vertex O Series](https://www.anchorterminal.com/compare/numeral-vs-vertex-tax.md)\n- [Quaderno vs Vertex O Series](https://www.anchorterminal.com/compare/quaderno-vs-vertex-tax.md)\n- [TaxCloud vs Vertex O Series](https://www.anchorterminal.com/compare/taxcloud-vs-vertex-tax.md)\n- [TaxJar vs Vertex O Series](https://www.anchorterminal.com/compare/taxjar-vs-vertex-tax.md)\n- [Vertex O Series vs Zamp](https://www.anchorterminal.com/compare/vertex-tax-vs-zamp.md)\n",
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    "description": "Vertex O Series scores 54.7 (C) on agent readiness against Fonoa's 51.7 (D), and leads in 4 of 7 scored categories. Fonoa leads on agent ergonomics. Both do tax calculate. Category scores, facts, verdicts and agent notes side by side.",
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    "published": "2026-10-01",
    "section": "tools",
    "title": "Fonoa vs Vertex O Series for AI agents, D 51.7 vs C 54.7",
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