# Regex Builder from Natural Language

> Regex Builder from Natural Language is a paid API for AI agents from linked-aimed-reproduced-changing.trycloudflare.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-12).

Generates a regular expression from a plain-English description, returning the regex pattern and a sample test string.

## Facts

- Endpoint: POST https://linked-aimed-reproduced-changing.trycloudflare.com/v1/regex-build?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/regex-builder-from-natural-language-47b2534d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dphSRf-uqiboibn2KWBMl

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-builder-from-natural-language-47b2534d -d '<json body>'
```

Example prompt: Can you build me a regex that matches valid email addresses, and give me a test string that would match it?

## When to prefer this

Choose this endpoint when you need to quickly generate a working regex from a plain-English description without manually writing or debugging regex syntax. Ideal for developers who know what pattern they want conceptually but don't want to hand-craft the regex. It is more convenient than asking a general-purpose LLM because it returns just the regex and a test string with no surrounding prose, making it easy to extract and use directly in code.

## Known failure modes

- Ambiguous natural language description results in an overly broad or narrow regex
- Generated regex may not cover all edge cases of complex matching rules
- Returned test string may only cover a happy-path case, not boundary cases
- Cloudflare tunnel may be temporarily unavailable (502/503)
- Payment not processed correctly due to x402 protocol issues

## How this service works

Build a regex from a natural-language description. Returns just the regex + one test string.

## Output

Returns the generated regular expression pattern ready to use in code, along with one example test string that the regex is guaranteed to match.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "usage": {
   "type": "object"
  },
  "choices": {
   "type": "array"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/regex-builder-from-natural-language-47b2534d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from linked-aimed-reproduced-changing.trycloudflare.com](https://www.zero.xyz/host/linked-aimed-reproduced-changing.trycloudflare.com/llms.txt)