# Nero Labs Phone Number Validator > Nero Labs Phone Number Validator is a paid API for AI agents from x402-agent-tools.nerolabs.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-22). Validates up to 100 phone numbers from any country, returning E.164 format, national format, country, line type (mobile, landline, VoIP, toll-free), and validity status using Google's libphonenumber. ## Facts - Endpoint: POST https://x402-agent-tools.nerolabs.workers.dev/phone-check?utm_source=zero.xyz - Price: $0.002/call - Payment: x402 - Status: unknown - Last checked: 2026-10-22 - Activations on Zero: 0 - Tags: x402 - Canonical page: https://www.zero.xyz/c/nero-labs-phone-number-validator-7c1552ac - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_t2bBoTKhfcvSIW1d_5rZU Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently. ## How to call it through Zero Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`): ```sh zero fetch --capability nero-labs-phone-number-validator-7c1552ac -d '' ``` Example prompt: Can you validate these phone numbers for me — +44 20 7946 0123, 07825 123456, and (212) 555-0123 — and tell me which ones are valid, what country they're from, and whether they're mobile or landline? Assume UK for any numbers without a country code. ## When to prefer this Use this endpoint when you need bulk phone number validation, normalization to E.164, or line-type classification (mobile vs landline vs VoIP) without actually calling the number. Ideal for CRM data cleanup, SMS campaign pre-screening, sign-up form validation, or any workflow needing structured phone metadata at low cost ($0.002/number). Prefer this over live-lookup services when format validation and numbering-plan checks are sufficient and you don't need to verify the line is currently active. ## Known failure modes - Numbers without a country code and no defaultRegion set may be parsed incorrectly or flagged invalid - Batch exceeds 100 numbers — only up to 100 are supported per call - Ambiguous number formats with no region context returned as unknown type - VoIP numbers flagged as risky by default (can disable with flagVoip: false) - Numbers that exist in the numbering plan but are unallocated may still return phoneValid: true since no live line check is performed - Missing or wrong phoneField when using rows mode causes field detection fallback which may misidentify the phone column ## How this service works Pay-per-call tools for AI agents, 31 in all: read web pages and RSS feeds, OCR, PDF text, transcription; email, phone and domain checks; UK, Irish and Polish company lookups and UK risk reports; website contacts, tech stack and SEO audits; PageSpeed; AI review, job post and row enrichment; data cleaning, joins, dedupe and diffs; US and EU compliance rules. No account or API key: pay each call in USDC on Base over x402. ## Output Returns an array of row objects — one per input number — each enriched with: phoneValid (boolean), phoneStatus (valid/invalid/risky/duplicate), phoneE164 (e.g. +441174960012), phoneNational, phoneInternational, phoneCountry (ISO code), phoneCountryCallingCode, phoneType (mobile/fixed_line/voip/toll_free/etc.), isMobile, phoneReason, and phoneAllReasons. Also returns a summary object with counts by status, type, country, and reason, plus input metadata. ## Request schema (JSON Schema) ```json { "type": "object", "properties": { "keep": { "enum": [ "all", "valid", "valid_and_risky", "problems", "mobile" ], "type": "string", "description": "Which rows to return. all (default), valid, valid_and_risky, problems, or mobile (confirmed mobiles only, for SMS). The summary still counts every number." }, "rows": { "type": "array", "items": { "type": "object" }, "description": "JSON objects that each hold a phone number in one field. Every original field comes back untouched with the verdict fields added. Use this OR phones." }, "phones": { "type": "array", "items": { "type": "string" }, "description": "A plain list of phone numbers in any format, for example [\"+44 20 7946 0123\", \"07825 123456\", \"(212) 555-0123\"]. Bare numbers such as 2079460123 are also accepted. Use this OR rows." }, "flagVoip": { "type": "boolean", "description": "Default true: VoIP numbers come back risky." }, "phoneField": { "type": "string", "description": "Rows only. The field holding the number, for example \"phone\" or \"contact_number\". Leave out to detect it automatically." }, "defaultRegion": { "type": "string", "description": "Two-letter ISO country code assumed for numbers written without a country code, for example GB, US, AU, DE. Numbers starting with + are unaffected." }, "markDuplicates": { "type": "boolean", "description": "Default true: later repeats of the same E.164 number in this call come back duplicate." }, "flagNonPersonal": { "type": "boolean", "description": "Default true: toll free, shared cost, UAN, pager and voicemail numbers come back risky." }, "flagPremiumRate": { "type": "boolean", "description": "Default true: premium-rate numbers come back risky rather than valid." } } } ``` ## Response schema (JSON Schema) ```json { "type": "json", "example": { "rows": [ { "phone": "0117 496 0012", "isMobile": false, "phoneE164": "+441174960012", "phoneType": "fixed_line", "phoneValid": true, "lineChecked": false, "phoneReason": "ok", "phoneStatus": "valid", "phoneCountry": "GB", "phoneNational": "0117 496 0012", "phoneExtension": null, "phoneAllReasons": [ "ok" ], "phoneInternational": "+44 117 496 0012", "phoneCountryCallingCode": "+44" }, { "phone": "+1 (415) 555-0132", "isMobile": null, "phoneE164": "+14155550132", "phoneType": "fixed_line_or_mobile", "phoneValid": true, "lineChecked": false, "phoneReason": "ok", "phoneStatus": "valid", "phoneCountry": "US", "phoneNational": "(415) 555-0132", "phoneExtension": null, "phoneAllReasons": [ "ok" ], "phoneInternational": "+1 415 555 0132", "phoneCountryCallingCode": "+1" }, { "phone": "12345", "isMobile": null, "phoneE164": "+4412345", "phoneType": "unknown", "phoneValid": false, "lineChecked": false, "phoneReason": "too_short", "phoneStatus": "invalid", "phoneCountry": "GB", "phoneNational": "12345", "phoneExtension": null, "phoneAllReasons": [ "too_short" ], "phoneInternational": "+44 12345", "phoneCountryCallingCode": "+44" } ], "summary": { "keep": "all", "counts": { "risky": 0, "valid": 2, "invalid": 1, "duplicate": 0 }, "warnings": [], "inputMode": "phones", "phoneField": "phone", "typeCounts": { "fixed_line": 1, "fixed_line_or_mobile": 1 }, "mobileCount": 0, "checkedCount": 3, "reasonCounts": { "ok": 2, "too_short": 1 }, "countryCounts": { "GB": 1, "US": 1 }, "defaultRegion": "GB", "notInThisServer": "Region, allocated carrier and timezone lookups, Apify dataset / CSV / Excel / Google Sheet input, CSV and Excel export and webhooks are in t...", "inputRecordCount": 3, "liveLineCheckNote": "These checks confirm that a number is correctly formed and exists in its country numbering plan, and report its country and line type. They ...", "outputRecordCount": 3, "phoneFieldDetected": false, "liveLineCheckPerformed": false, "undeterminedMobileCount": 1 }, "_example_note": "Real output, trimmed: long lists cut to their first items and long text shortened." } } ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/nero-labs-phone-number-validator-7c1552ac/health.json - [Zero catalog index](https://www.zero.xyz/llms.txt) - [Other services from x402-agent-tools.nerolabs.workers.dev](https://www.zero.xyz/host/x402-agent-tools.nerolabs.workers.dev/llms.txt)