# Synapse API — Gnosis Gas Estimator

> Synapse API — Gnosis 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 2026-09-14).

Estimates gas cost for a transaction on the Gnosis blockchain network before execution

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/gnosis/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/synapse-api-gnosis-gas-estimator-20c219b0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_BUTbvCwfEbNNb-3M7sCQq

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-gnosis-gas-estimator-20c219b0 -d '<json body>'
```

Example prompt: Estimate the gas cost for a Gnosis transaction from 0xSenderAddress to 0xRecipientAddress with value 0x0 and calldata 0xabcdef — I want to know the fee before I send it.

## When to prefer this

Choose this endpoint when you specifically need gas estimation for the Gnosis (formerly xDAI) blockchain network. It is a pre-execution simulation tool — ideal before committing any transaction to avoid overpaying or running out of gas. Use it when your workflow targets Gnosis mainnet specifically rather than Ethereum, Polygon, or other EVM chains.

## Known failure modes

- Invalid or malformed Ethereum address in 'to' or 'from' fields returns an error
- Invalid hex-encoded 'data' or 'value' fields cause parsing errors
- Transaction simulation fails if the contract call would revert, returning an execution error
- Network connectivity issues with Gnosis RPC node result in timeout or 503 errors
- 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 an estimated gas amount (in gas units) required to execute the specified transaction on the Gnosis network, allowing the caller to gauge cost before committing the 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/synapse-api-gnosis-gas-estimator-20c219b0/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)