# Phantom API — Citrea Gas Estimation

> Phantom API — Citrea Gas Estimation is a paid API for AI agents from phantom-api-omega.vercel.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-20).

Estimates gas costs for a transaction on the Citrea network before submission

## Facts

- Endpoint: POST https://phantom-api-omega.vercel.app/api/citrea/gas/estimate?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/phantom-api-citrea-gas-estimation-032b1303
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_WE_Jmk5HzRt0eMud1lR-5

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 phantom-api-citrea-gas-estimation-032b1303 -d '<json body>'
```

Example prompt: Before I send this transaction on Citrea — calling contract 0xAbC...123 with this calldata from my wallet 0xDef...456 with a value of 0.01 ETH — can you estimate how much gas it'll need?

## When to prefer this

Use this endpoint when you need a gas estimate specifically on the Citrea Bitcoin Layer 2 network before submitting a transaction. Prefer this over generic Ethereum gas estimators when the target chain is Citrea. It is pay-per-call at $0.01 USDC via x402, making it suitable for agents that need occasional on-demand estimates without a subscription.

## Known failure modes

- Invalid or malformed address in 'to' or 'from' fields returns a validation error
- Malformed or non-hex 'data' field may cause a parsing error
- Network unavailability or RPC timeout on Citrea returns a 5xx error
- Insufficient USDC payment (must include $0.01 via x402 protocol) returns HTTP 402
- Transaction simulation that would revert on-chain may return an error or revert reason

## How this service works

Lightning-fast access to blockchain data, smart contract insights, and Web3 infrastructure across 57+ networks. Pay-per-call via x402.

## Output

Returns a gas estimate (in gas units) for the described transaction on the Citrea network, allowing callers to predict transaction costs and validate feasibility before on-chain submission.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "to": {
   "type": "string"
  },
  "data": {
   "type": "string"
  },
  "from": {
   "type": "string"
  },
  "value": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/phantom-api-citrea-gas-estimation-032b1303/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from phantom-api-omega.vercel.app](https://www.zero.xyz/host/phantom-api-omega.vercel.app/llms.txt)