Regex Tester API

Test regex patterns against strings. Get all matches, capture groups, positions, and plain-English pattern explanations. 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": {
    "regex-generator": {
      "url": "https://regex-generator.api.klymax402.com/mcp"
    }
  }
}

Related MCP server: x402-sub-agent-mcp

Quickstart -- HTTP (x402)

curl -X POST "https://regex-generator.api.klymax402.com/api/test" \
  -H "Content-Type: application/json" \
  -d '{"pattern":"...","testStrings":"..."}'
# -> 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

text_test_regex

Use this when you need to test a regular expression against one or more strings. Returns all matches, capture groups, positions, and a human-readable explanation of the pattern.

Parameters

Example response:

{"pattern":"\d{3}-\d{4}","flags":"g","explanation":"Matches 3 digits, a hyphen, then 4 digits","results":[{"input":"Call 555-1234","matched":true,"matches":[{"value":"555-1234","index":5,"groups":[]}]}],"totalMatches":1}

When to use: validating regex patterns before deploying them in code, debugging why a pattern fails to match, or extracting structured data from text. Use this BEFORE writing complex regex into production code.

Not for: text classification (use text_classify_content), PII detection (use privacy_detect_pii), text comparison (use text_compare_diff).

Example agent prompts

• "Test a regular expression against one or more strings"

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