# Git Best Common Ancestor Antichain Verifier

> Git Best Common Ancestor Antichain Verifier is a paid API for AI agents from detect.halowerk.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-11-04).

Validates a claimed count of best common ancestors (merge bases) for two or more anonymous Git commit tips by checking the antichain structure.

## Facts

- Endpoint: POST https://detect.halowerk.com/v1/F-A-NEXT-GIT_MERGE_BASES/git-best-common-ancestor-antichain?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-11-04
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/git-best-common-ancestor-antichain-verifier-cdfbbd2d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_0gn86EwYU09MJev1sMQkg

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 git-best-common-ancestor-antichain-verifier-cdfbbd2d -d '<json body>'
```

Example prompt: Can you verify that the claimed number of best common ancestors is correct for these two git commit tips — tips [42, 7], claim of 1, with parents [[3,5],[1,2]]?

## When to prefer this

Use this endpoint when you need to programmatically verify that a claimed count of Git merge bases (best common ancestors) is correct for a pair or set of commit tips, especially in automated CI/CD pipelines, merge tooling validation, or debugging unexpected merge behavior. Prefer this over implementing custom DAG antichain logic when you want a pay-per-call validation service without maintaining graph traversal infrastructure.

## Known failure modes

- Mismatched array sizes between tips and parents arrays causing schema validation failure
- Claim value outside allowed numeric range (-1000000000000 to 1000000000000)
- Tips or parents arrays exceeding 512-item limit
- Malformed parent arrays (non-numeric or missing inner arrays)
- Internally inconsistent graph structure where the antichain cannot be computed
- Network timeout or service unavailability returning HTTP 402 or 5xx

## How this service works

Prüft die behauptete Zahl bester gemeinsamer Vorfahren zweier anonymer Git-Commitspitzen.

## Output

A validation response indicating whether the claimed number of best common ancestors (merge bases) for the given commit tips matches the actual antichain structure derived from the provided parent adjacency data. Returns correctness of the claim.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "artifact": {
   "type": "object",
   "required": [
    "git_merge_bases"
   ],
   "properties": {
    "git_merge_bases": {
     "type": "object",
     "required": [
      "claim",
      "parents",
      "tips"
     ],
     "properties": {
      "tips": {
       "type": "array",
       "items": {
        "type": "number",
        "maximum": 1000000000000,
        "minimum": -1000000000000
       },
       "maxItems": 512
      },
      "claim": {
       "type": "number",
       "maximum": 1000000000000,
       "minimum": -1000000000000
      },
      "parents": {
       "type": "array",
       "items": {
        "type": "array",
        "items": {
         "type": "number",
         "maximum": 1000000000000,
         "minimum": -1000000000000
        },
        "maxItems": 512
       },
       "maxItems": 512
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/git-best-common-ancestor-antichain-verifier-cdfbbd2d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from detect.halowerk.com](https://www.zero.xyz/host/detect.halowerk.com/llms.txt)