# Synapse API — Katana Gas Estimator

> Synapse API — Katana Gas Estimator is a paid API for AI agents from synapse-api-brown.vercel.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-13).

Estimates the gas required for a transaction on the Katana blockchain network given sender, recipient, calldata, and value.

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/katana/gas/estimate
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synapse-api-katana-gas-estimator-31a4730c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_RieHP-j96B26stvlu-FkZ

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 synapse-api-katana-gas-estimator-31a4730c -d '<json body>'
```

Example prompt: Estimate how much gas the following transaction will use on Katana — from 0xAbC123... to 0xDeF456..., with calldata 0xa9059cbb... and value 0.

## When to prefer this

Use this endpoint when you need a gas estimate specifically for the Katana blockchain network before submitting a transaction. Prefer this over generic Ethereum gas estimators when targeting Katana, and use it as a pre-flight check to avoid out-of-gas failures or to surface revert conditions before broadcasting.

## Known failure modes

- Invalid or malformed address in 'from' or 'to' fields returns an error
- Malformed or non-hex 'data' field causes a parse error
- Transaction would revert on-chain — estimation may fail with a revert reason
- Network unavailability or RPC node errors cause service timeouts
- Missing required fields may return a 400 bad request

## How this service works

High-speed API suite for AI processing, web scraping, and smart data utilities across 57+ blockchain networks. Pay-per-call via x402.

## Output

Returns a gas estimate (in gas units) for the described transaction on the Katana network, allowing callers to budget fees and set appropriate gas limits before broadcasting a transaction.

## 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/synapse-api-katana-gas-estimator-31a4730c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from synapse-api-brown.vercel.app](https://www.zero.xyz/host/synapse-api-brown.vercel.app/llms.txt)