# Polygon Bridge Amount Consistency Validator

> Polygon Bridge Amount Consistency Validator is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.015/call, status unknown (last checked 2026-09-15).

Validates that token amounts are consistent across stages of a Polygon PoS bridge transaction (lock, mint, burn, exit)

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/polygon_bridge_amount_consistency/invoke
- Price: $0.015/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/polygon-bridge-amount-consistency-validator-73342ee8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gJ-Fk_FPUqFXv1R1f0f5E

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 polygon-bridge-amount-consistency-validator-73342ee8 -d '<json body>'
```

Example prompt: Can you check whether my Polygon PoS bridge transaction amounts are consistent across the lock and mint stages? Here's the transaction data as JSON: {"amounts":[{"amount_atomic":"100000000","stage":"lock"},{"amount_atomic":"100000000","stage":"mint"}], "chain_id":"137"}.

## When to prefer this

Use this endpoint when you need to programmatically verify that amounts flowing through a Polygon PoS bridge are consistent across transaction stages, especially when auditing cross-chain transfers, building bridge monitoring tools, or validating that end users received the correct token amounts. Prefer this over manual inspection when you have structured transaction data and need a fast, deterministic consistency check with clear stage-by-stage analysis.

## Known failure modes

- Incomplete transaction data with missing required fields results in analysis flagging missing stages
- Token mechanics (fees, rebases) not supplied in the request lead to warnings that amounts may be inaccurate
- Invalid or unsupported chain IDs not in the accepted set (137, 80002) may cause analysis errors
- Malformed JSON in request_json field returns a validation error
- Caller-supplied data only — no on-chain verification is performed, so accuracy depends entirely on input quality

## How this service works

Explore 330 pay-per-call x402 API services and 27 agent-native digital products, with Base USDC pricing, secure Polar checkout, and free discovery.

## Output

Returns a JSON analysis including whether amounts are consistent across supplied bridge stages, a list of missing stages not yet evidenced, any warnings about token mechanics (e.g. fees, rebases), the accepted chain IDs, the bridge model description, and the completion policy. Also includes a status field and a SHA-256 hash of the result for auditability.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "request_json": {
   "type": "string",
   "maxLength": 65536,
   "minLength": 2
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "replay": false,
  "result": {
   "warnings": [
    "Token mechanics such as fees/rebases must be explicitly supplied."
   ],
   "service_id": "polygon_bridge_amount_consistency",
   "analysis_json": "{\"amounts\":[{\"amount_atomic\":\"100\",\"stage\":\"lock\"}],\"consistent\":true,\"missing_stages\":[\"mint\",\"burn\",\"exit\"],\"network_context\":{\"accepted_chain_ids\":[\"137\",\"80002\"],\"bridge_model\":\"root-child state sync plus checkpoint evidence\",\"completion_policy\":\"never inferred without supplied evidence\",\"protocol_family\":\"Polygon PoS\"}}",
   "evidence_scope": "caller_supplied_data",
   "analyzed_network": "polygon"
  },
  "status": "succeeded",
  "receipt": {
   "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
   "usage": [],
   "status": "succeeded",
   "network": "eip155:8453",
   "artifacts": [],
   "endedAtMs": 0,
   "latencyMs": 0,
   "paymentId": "example-payment",
   "receiptId": "example-receipt",
   "requestId": "example-request",
   "serviceId": "polygon_bridge_amount_consistency",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "15000",
   "resultSha256": "9c59908478ded7f1d441772a92fe929f05246e4a9b06c00dd6d8e3304d7e4fa9",
   "serviceVersion": "1.0.0",
   "settlementReference": "0x0000000000000000000000000000000000000000000000000000000000000000"
  },
  "artifacts": [],
  "requestId": "example-request",
  "executionId": "example-execution"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/polygon-bridge-amount-consistency-validator-73342ee8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from signalharness.ai](https://www.zero.xyz/host/signalharness.ai/llms.txt)