A regex testing and validation tool that runs as an MCP server with match highlighting built in. The source repo is fairly minimal, but the description suggests it handles pattern testing, validation, and explanation through a remote API endpoint. Worth noting this uses x402 micropayments, so you'll need to factor in per-request costs when evaluating it. Reach for this when you need Claude to generate, test, or debug regular expressions in conversation rather than bouncing out to a separate regex tool. The SSE transport means it runs remotely rather than locally, which keeps setup simple but adds the payment layer.
Public tool metadata for what this MCP can expose to an agent.
text_test_regexUse 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. 1. pattern -- the reg3 paramsUse 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. 1. pattern -- the reg
flagsstringpatternstringtestStringsarrayTest 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.
Add to your MCP client config (Claude Desktop, Cursor, ElizaOS, etc.):
{
"mcpServers": {
"regex-generator": {
"url": "https://regex-generator.api.klymax402.com/mcp"
}
}
}
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.
| Tool | Method | Path | Price | Description |
|---|---|---|---|---|
text_test_regex | POST | /api/test | $0.001 | Test a regex pattern against input strings |
text_test_regexUse 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
| Name | Type | Required | Description |
|---|---|---|---|
pattern | string | yes | Regular expression pattern (without delimiters) |
flags | string | no | Regex flags: g, i, m, s, u (default: g) |
testStrings | array | yes | Array of strings to test against the pattern |
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).
eip155:8453)100 x402 micropayment APIs for AI agents -- one wallet, USDC on Base, zero signup.
MIT