# Bounty Engineer Delta Witness

> Bounty Engineer Delta Witness is a paid API for AI agents from bounty-engineer-x402-prod.onrender.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-12).

Compares two snapshots of a JSON resource and returns a structured diff (added, removed, replaced paths) along with SHA-256 hashes and change metadata.

## Facts

- Endpoint: POST https://bounty-engineer-x402-prod.onrender.com/v1/delta-witness?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/bounty-engineer-delta-witness-af8fd9a5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_4yHy0zQjKWy0U2eP5lFXW

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 bounty-engineer-delta-witness-af8fd9a5 -d '<json body>'
```

Example prompt: Compare these two JSON snapshots of the order record and tell me exactly which fields changed, what the before and after values were, and give me the SHA-256 hashes for both — limit the results to 10 changes.

## When to prefer this

Use this endpoint when you need a structured, path-level diff of two JSON snapshots with cryptographic integrity hashes, especially in agentic workflows where you want to verify state changes, audit modifications, or detect drift. Prefer this over generic diff tools when you need SHA-256 verification of both states and a machine-readable list of changed paths suitable for downstream agent logic.

## Known failure modes

- Missing or malformed before/after inputs may return an error or empty diff
- max_changes set too low may truncate results and return truncated:true without full diff
- If both snapshots are identical, changed is false and changes array is empty
- Network timeout or server error on Render.com free tier may cause 502/503 responses
- Payment failure via x402 protocol results in 402 Payment Required with no diff returned

## How this service works

Machine-buyable infrastructure for autonomous agents: API cost routing, margin optimization, funding-rate data, webpage extraction, result verification, spend controls, retry planning, state, tender search and GitHub bounty intelligence.

## Output

Returns a JSON object with: a boolean 'changed' flag, an array of 'changes' (each with path, type, before value, after value), SHA-256 hashes of both the before and after states, the total change_count, and a 'truncated' flag indicating if results were capped by max_changes.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "after": {},
  "before": {},
  "max_changes": {
   "type": "integer"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "mode": "delta_witness",
  "changed": true,
  "changes": [
   {
    "path": "/price",
    "type": "replace",
    "after": 12,
    "before": 10
   },
   {
    "path": "/status",
    "type": "replace",
    "after": "closed",
    "before": "open"
   }
  ],
  "truncated": false,
  "after_sha256": "97bcf68fe8fda0941ccb119acdd65f20c536b3154d3b5ffdccd70b6e04e23891",
  "change_count": 2,
  "before_sha256": "c6a3e41eb38bec743730cdceaa6715ec3f8ea45d2be717b1dcab7b7fbba011e1"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bounty-engineer-delta-witness-af8fd9a5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bounty-engineer-x402-prod.onrender.com](https://www.zero.xyz/host/bounty-engineer-x402-prod.onrender.com/llms.txt)