# Phantom API — Sei Network Gas Estimator

> Phantom API — Sei Network Gas Estimator 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 2026-10-17).

Estimates gas costs for a transaction on the Sei blockchain network before submission

## Facts

- Endpoint: POST https://phantom-api-omega.vercel.app/api/sei/gas/estimate?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-17
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/phantom-api-sei-network-gas-estimator-6cee20a7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_uABxfMgpI1_nNtbIBxt2K

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-sei-network-gas-estimator-6cee20a7 -d '<json body>'
```

Example prompt: Before I send 10 SEI to 0xAbCd...1234 from my wallet 0x9876...FEDC on the Sei network, can you estimate how much gas this transaction will cost?

## When to prefer this

Choose this endpoint when you need gas cost estimates specifically on the Sei network prior to submitting a transaction. It is ideal for pre-flight fee checks, DeFi transaction cost validation, and smart contract interaction budgeting on Sei. Use this over generic gas tools when you need Sei-specific estimation via a pay-per-call model without managing your own RPC infrastructure.

## Known failure modes

- Invalid or malformed Ethereum-style address in 'to' or 'from' fields returns an error
- Invalid hex calldata in 'data' field causes estimation failure
- Transaction that would revert on-chain may return an error or zero estimate
- Network congestion or Sei RPC node unavailability causes timeout
- Missing required fields may result in a 400 Bad Request

## 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 Sei network transaction, allowing the caller to understand expected transaction fees before committing to on-chain execution.

## 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-sei-network-gas-estimator-6cee20a7/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)