# Regex Match & Backtracking Risk Analyzer

> Regex Match & Backtracking Risk Analyzer is a paid API for AI agents from sigtap-outreach-api.sigtap.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Runs a regex pattern against input text and returns all matches with capture groups, total match count, and a backtracking-risk heuristic

## Facts

- Endpoint: GET https://sigtap-outreach-api.sigtap.workers.dev/tools/regex
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/regex-match-backtracking-risk-analyzer-efd9920b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_D6yrigCWzDOxtEcuWgBRC

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability regex-match-backtracking-risk-analyzer-efd9920b
```

Example prompt: Run the regex pattern \d{4}-\d{2}-\d{2} against this string 'Order placed on 2024-03-15 and shipped on 2024-04-01' and tell me all the matches, capture groups, and whether the pattern has any backtracking risk.

## When to prefer this

Choose this endpoint when you need to both execute a regex match AND get a safety assessment of the pattern's backtracking risk in a single call — particularly useful before deploying regex patterns to production systems where ReDoS attacks are a concern. Prefer this over a plain regex library when you want structured match results with group extraction and a heuristic risk flag without setting up local infrastructure.

## Known failure modes

- Invalid regex pattern syntax returns an error
- Missing required 'input' parameter returns a validation error
- Extremely long input strings may time out on the Cloudflare Worker
- Pattern with no matches returns count 0 and an empty matches array
- Malformed query parameters return 400-level errors

## How this service works

Paid micro-utilities for cold-email outreach agents: domain deliverability audits, cold-email grading, template generation, plus a tools toolbox (hashing, JWT decode, IDs, slugs, JSON, regex, crypto prices, domain age, weather). Paid via x402 (USDC on Base). One signature per call. No keys. FREE CHECK: GET /preview/<paid-path> (same URL with /preview/ prefix) returns a 200 demo sample - verify output shape before paying. PAID CALL: GET the url -> 402 challenge -> sign + retry with X-PAYMENT -> settled on-chain (USDC, Base). Ready-to-paste client: GET /llms.txt section "Pay in one call". Catalog+MCP twin: /llms.txt.

## Output

A JSON object containing: the original pattern, total count of matches, an array of match objects each with the matched string, its character index in the input, and any capture groups, plus a backtracking_risk object with a risk level (low/medium/high) and an array of reasons explaining any detected risks.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "count": 2,
  "matches": [
   {
    "index": 0,
    "match": "42",
    "groups": []
   }
  ],
  "pattern": "\\d+",
  "backtracking_risk": {
   "risk": "low",
   "reasons": []
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/regex-match-backtracking-risk-analyzer-efd9920b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from sigtap-outreach-api.sigtap.workers.dev](https://www.zero.xyz/host/sigtap-outreach-api.sigtap.workers.dev/llms.txt)