Phone Number Validation API

Validate phone numbers worldwide -- carrier, line type, country, E.164 format. Single and batch (50) modes. Pay-per-call via x402 (USDC on Base L2) -- no API key, no signup, no rate-limit wall.

Part of the klymax402 marketplace -- 100 x402 micropayment APIs for AI agents, one wallet, USDC on Base.

Quickstart -- MCP

Add to your MCP client config (Claude Desktop, Cursor, ElizaOS, etc.):

{
  "mcpServers": {
    "phone-validation": {
      "url": "https://phone-validation.api.klymax402.com/mcp"
    }
  }
}

Related MCP server: CorteX402

Quickstart -- HTTP (x402)

curl "https://phone-validation.api.klymax402.com/api/validate?phone=..."
# -> 402 Payment Required, with an x402 payment challenge in the response body

Any x402-aware client (@x402/fetch, x402-agent-tools, ATXP) handles the 402 -> sign -> retry cycle automatically.

Tools

phone_validate_number

Use this when you need to validate a phone number and get carrier info. Returns structured validation data in JSON.

Parameters

Example response:

{"valid":true,"e164":"+33612345678","countryCode":"FR","countryName":"France","carrier":"Orange","lineType":"mobile","localFormat":"06 12 34 56 78","internationalFormat":"+33 6 12 34 56 78"}

When to use: sending SMS or calling a number, FOR CRM data cleaning, lead validation, fraud detection, and KYC phone verification.

Not for: SMS capability check (use sms_validate_number), email validation (use email_verify_address), person data (use person_enrich_from_email).

phone_validate_batch

Use this when you need to validate multiple phone numbers at once (up to 50). Returns an array of validation results in JSON.

Parameters

Example response:

{"results":[{"phone":"+14155551234","valid":true,"e164":"+14155551234","countryCode":"US","carrier":"T-Mobile","lineType":"mobile"},{"phone":"invalid","valid":false}],"total":2,"validCount":1}

When to use: bulk CRM cleaning, importing contact lists, deduplication pipelines, and batch lead validation.

Not for: single numbers (use phone_validate_number), SMS capability (use sms_validate_number).

Example agent prompts

• "Validate a phone number and get carrier info"

• "Validate multiple phone numbers at once (up to 50)"

Payment

• Protocol: x402 -- HTTP-native pay-per-call, no signup, no API key

• Network: Base L2 (eip155:8453)

• Asset: USDC

• Facilitator: Coinbase CDP (primary), PayAI (fallback)

• Also reachable via ATXP (OAuth-wrapped x402, RFC 9728 protected-resource metadata)

Part of klymax402

100 x402 micropayment APIs for AI agents -- one wallet, USDC on Base, zero signup.

• Catalog: https://klymax402.com/llms.txt

• Full API reference: https://klymax402.com/llms-full.txt

• Live stats: https://klymax402.com/stats

License

MIT