# Solana Durable Nonce Inspector

> Solana Durable Nonce Inspector 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).

Analyzes a Solana transaction's durable nonce usage, checking whether the advance-nonce instruction is present, correctly placed, and whether the nonce matches the transaction blockhash.

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/solana_durable_nonce_inspect/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/solana-durable-nonce-inspector-948cb86e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_zjo8ItE2Ox6wDG-Z2Div2

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 solana-durable-nonce-inspector-948cb86e -d '<json body>'
```

Example prompt: Can you inspect this Solana transaction JSON and tell me whether the durable nonce is set up correctly — specifically if the advance nonce instruction is present, where it appears, whether the nonce matches the blockhash, and flag any warnings?

## When to prefer this

Use this endpoint when you need to programmatically validate Solana durable nonce transactions before broadcasting, debug nonce-related rejection errors, or audit transaction structure in a CI/automated pipeline. It is purely static analysis on caller-supplied data — it does not make RPC calls to the Solana network, so it is fast and cheap ($0.015 USDC) but cannot verify on-chain nonce state or account balances.

## Known failure modes

- Malformed or invalid transaction JSON causes parsing failure
- Nonce account address is the system default (all zeros) when not properly set
- advance_instruction_index returns -1 if no advance nonce instruction is present
- Does not query on-chain nonce freshness or reserve balance — warnings included in response
- Input JSON exceeding 65536 characters will be rejected
- Incomplete transaction structure may result in null blockhash and false nonce match

## 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 structured analysis including: whether the nonce matches the transaction blockhash, the index of the advance nonce instruction (-1 if absent), the nonce authority pubkey, the nonce account pubkey, whether advance-first ordering is satisfied, and an array of warnings (e.g. missing advance nonce instruction). Also indicates the analyzed network (solana) and evidence scope (caller-supplied data).

## 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": [
    "Does not query nonce freshness or reserve balance."
   ],
   "service_id": "solana_durable_nonce_inspect",
   "analysis_json": "{\"advance_first\":false,\"advance_instruction_index\":-1,\"authority\":\"11111111111111111111111111111111\",\"nonce\":\"11111111111111111111111111111111\",\"nonce_matches_blockhash\":false,\"transaction_blockhash\":null,\"warnings\":[\"advance nonce instruction not supplied\"]}",
   "evidence_scope": "caller_supplied_data",
   "analyzed_network": "solana"
  },
  "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": "solana_durable_nonce_inspect",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "15000",
   "resultSha256": "b29cd4ef5dc21593e7b53382c68a452a6188821fe43674bc4036d6b1d8220b23",
   "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/solana-durable-nonce-inspector-948cb86e/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)