Summary
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.
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Public tool metadata for what this MCP can expose to an agent.
1 tools
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 params
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. 1. pattern -- the reg
Parameters* required
flagsstringRegex flags: g, i, m, s, u (default: g)
patternstringRegular expression pattern (without delimiters)
testStringsarrayArray of strings to test against the pattern
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"
}
}
}
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
| Tool | Method | Path | Price | Description |
|---|---|---|---|---|
text_test_regex | POST | /api/test | $0.003 | Test a regex pattern against input strings |
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
| 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).
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
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Plug Mailtrap into your AI workflow and let it handle the email.
Connect Mailtrap MCP →Agent, run crypto. Access onchain data & trade routes via 1inch.
Install now →Make coding agent sessions - Searchable, Shareable, Vendor-neutral & Scored.
Try For Free →Your agent targets a perfect 10 Code Health score. Deterministic. Every commit.
Try For Free →Integrate web data into your AI product. One API to scrape website & brand data.
Get API Key Now →belt cli automatically finds the best tools and skills for your agent. image, video, music, tts...
one prompt install →