# Synapse API — Sonic Gas Estimator

> Synapse API — Sonic 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 2026-09-15).

Estimates gas cost for a transaction on the Sonic blockchain network before sending it

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/sonic/gas/estimate
- 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/synapse-api-sonic-gas-estimator-b7936c5b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Lcovctdk6Yz9qjO2tLSvk

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-sonic-gas-estimator-b7936c5b -d '<json body>'
```

Example prompt: Estimate the gas needed for a Sonic transaction from 0xABC...123 to 0xDEF...456 with calldata 0xa9059cbb... and value 0.0 ETH before I send it.

## When to prefer this

Use this endpoint when you specifically need gas estimation on the Sonic blockchain network (not Ethereum mainnet or other EVM chains). It is appropriate when you want a pre-flight fee check before executing a transaction, to avoid overpaying or having transactions fail due to insufficient gas. Prefer this over generic Ethereum gas estimators when your transaction targets the Sonic network.

## Known failure modes

- Invalid or malformed address in 'to' or 'from' fields returns an error
- Invalid hex data in the 'data' field causes parsing failure
- Sonic network node unavailability leads to timeout or 503 error
- Missing required fields may return a validation error
- Simulated transaction that would revert may return an error or revert reason

## 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 an estimated gas amount (in gas units) for the described transaction on the Sonic network, allowing the caller to assess fees and decide whether to proceed with 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/synapse-api-sonic-gas-estimator-b7936c5b/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)