# Quantum Error Correction - Classical Repetition Code Decoder

> Quantum Error Correction - Classical Repetition Code Decoder is a paid API for AI agents from quantum.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-14).

Majority-decodes an odd-length repetition-code bit word to correct a single logical bit error and returns the corrected codeword alongside the XOR syndrome.

## Facts

- Endpoint: POST https://quantum.halowerk.com/v1/error-correction
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/quantum-error-correction-classical-repetition-code-decoder-7830c994
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_CvUn6h3BDIOKKZOlA7TTW

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 quantum-error-correction-classical-repetition-code-decoder-7830c994 -d '<json body>'
```

Example prompt: Run majority-vote error correction on this repetition-coded bit string '1101101' — give me the corrected codeword and the XOR syndrome.

## When to prefer this

Choose this endpoint when you need a quick, cheap ($0.003) demonstration or verification of classical majority-vote error correction on a repetition code. It is ideal for educational demos, testing error-correction logic, or validating small odd-length codewords programmatically. Do not use it for surface-code simulation, fault-tolerant quantum error correction, coherent error modeling, or decoding non-repetition codes.

## Known failure modes

- Even-length bit string provided — only odd-length inputs are accepted (minLength 3, pattern ^[01]+$)
- Bit string shorter than 3 bits — below the minimum required for majority voting
- Bit string longer than 99 characters — exceeds maxLength limit
- Non-binary characters in input — only '0' and '1' are valid
- Empty string — rejected by minLength constraint

## How this service works

Treats a caller-supplied odd-length bit word as a classical repetition code, majority-decodes one logical bit, and reports the corrected word and adjacent XOR syndrome. This narrow demonstration is not a surface-code simulation and does not model coherent quantum errors, measurements or fault-tolerant thresholds.

## Output

The endpoint returns the majority-decoded corrected bit word (the logical bit replicated to odd length), the recovered logical bit value, and the XOR syndrome indicating which positions disagreed with the majority — useful for understanding where errors occurred in the codeword.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "encoded_bits": {
   "type": "string",
   "pattern": "^[01]+$",
   "maxLength": 99,
   "minLength": 3,
   "description": "Odd-length repetition-code word."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/quantum-error-correction-classical-repetition-code-decoder-7830c994/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from quantum.halowerk.com](https://www.zero.xyz/host/quantum.halowerk.com/llms.txt)