# Phantom API — Gas Estimation

> Phantom API — 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 2026-09-14).

Estimates the gas required to execute a given Ethereum-compatible transaction before it is submitted on-chain.

## Facts

- Endpoint: POST https://phantom-api-omega.vercel.app/api/adi/gas/estimate
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/phantom-api-gas-estimation-7b671cb0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_tMvVdiaYdCwp0I6stJ1Zn

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-gas-estimation-7b671cb0 -d '<json body>'
```

Example prompt: Before I send this transaction, estimate how much gas it will need — I'm sending from 0xAbC...123 to the Uniswap router at 0xDef...456 with this calldata: 0xa9059cbb... and a value of 0 ETH.

## When to prefer this

Use this endpoint when you need a fast, pay-per-call gas estimate without managing your own RPC node or signing up for a long-term subscription. Ideal for agents that need pre-flight cost checks before submitting Ethereum-compatible transactions, especially in multi-chain environments where Phantom API's 57+ network coverage matters.

## Known failure modes

- Invalid or malformed Ethereum addresses return an error response
- Malformed or non-hex calldata causes a parsing error
- Reverted simulation — if the transaction would revert on-chain, the estimate may fail or return an error
- Missing required fields may result in a 400-level error
- Network congestion or upstream RPC failures may cause timeouts or 500-level errors
- Payment not included or insufficient USDC results in 402 Payment Required

## 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 an estimated gas units figure for the described transaction, indicating how much computational work the EVM would need to process it. Helps callers set appropriate gas limits before broadcasting a transaction on-chain.

## 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-gas-estimation-7b671cb0/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)