# Base EIP-1559 Transaction Decode

> Base EIP-1559 Transaction Decode is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Decodes and analyzes a Base network EIP-1559 (type 0x2) transaction, extracting fields like chain ID, gas parameters, calldata, and network context.

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/base_eip1559_transaction_decode/invoke
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-eip-1559-transaction-decode-41401069
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_nE_5fehis9xSBsTut7w7N

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 base-eip-1559-transaction-decode-41401069 -d '<json body>'
```

Example prompt: Can you decode this Base EIP-1559 transaction JSON for me and tell me the gas limit, max fee per gas, calldata size, recipient address, and any warnings about it?

## When to prefer this

Choose this endpoint when you need to decode and inspect a Base network EIP-1559 (type 0x2) transaction before signing or broadcasting it, or to audit its fields programmatically. Ideal for agents working in the Base/OP Stack ecosystem that need structured extraction of gas parameters, calldata, and network context without connecting to a node. Prefer it over general-purpose Ethereum decoders when you specifically need Base mainnet network context and OP Stack fee model metadata.

## Known failure modes

- Invalid or malformed transaction JSON returns a parsing error
- Transaction data not conforming to EIP-1559 type 0x2 structure may return partial or empty fields
- Chain ID not matching Base (8453 or 84532) may yield a network mismatch warning
- Oversized input exceeding 65536 characters will be rejected
- Unsigned transactions will always include a warning that broadcast/inclusion is not proven

## 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 object containing decoded transaction fields (chain_id, to address, value, nonce, gas_limit, max_fee_per_gas, max_priority_fee_per_gas, data/calldata, calldata_bytes, type), the analyzed network (base_mainnet), network context (OP Stack protocol family, accepted chain IDs, fee model), evidence scope, warnings (e.g. unsigned data caveat), and a full receipt with service metadata and a result SHA-256 hash.

## 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": [
    "Unsigned or supplied transaction data does not prove broadcast or inclusion."
   ],
   "service_id": "base_eip1559_transaction_decode",
   "analysis_json": "{\"calldata_bytes\":68,\"chain_id\":\"8453\",\"data\":\"0xa9059cbb00000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000064\",\"gas_limit\":\"21000\",\"max_fee_per_gas\":\"120\",\"max_priority_fee_per_gas\":\"5\",\"network\":\"base_mainnet\",\"network_context\":{\"accepted_chain_ids\":[\"8453\",\"84532\"],\"deposit_transaction_type\":\"0x7e\",\"fee_model\":\"L2 execution plus caller-supplied L1 data/operator components\",\"protocol_family\":\"OP Stack\"},\"nonce\":\"1\",\"to\":\"0x0000000000000000000000000000000000000002\",\"type\":\"0x2\",\"value\":\"0\"}",
   "evidence_scope": "caller_supplied_data",
   "analyzed_network": "base"
  },
  "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": "base_eip1559_transaction_decode",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "10000",
   "resultSha256": "b8f008e1ad2ebd54e69aeb7548fe98c69fb72d2571835fedd48ef59f441e3b30",
   "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/base-eip-1559-transaction-decode-41401069/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)