# Regex Tester API

[![MCP Server](https://img.shields.io/badge/MCP-server-blue)](https://regex-generator.api.klymax402.com/mcp)
[![x402](https://img.shields.io/badge/payments-x402-6E56CF)](https://x402.org)
[![License: MIT](https://img.shields.io/badge/license-MIT-green)](LICENSE)

Test regex patterns against strings. Get all matches, capture groups, positions, and plain-English pattern explanations. Pay-per-call via [x402](https://x402.org) (USDC on Base L2) -- no API key, no signup, no rate-limit wall.

Part of the [klymax402](https://klymax402.com) 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.):

```json
{
  "mcpServers": {
    "regex-generator": {
      "url": "https://regex-generator.api.klymax402.com/mcp"
    }
  }
}
```

## Quickstart -- HTTP (x402)

```bash
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`](https://www.npmjs.com/package/@x402/fetch), [`x402-agent-tools`](https://www.npmjs.com/package/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:

```json
{"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](https://x402.org) -- 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](https://atxp.ai) (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