# Synapse API — Bob Gas Estimator

> Synapse API — Bob 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 2026-10-16).

Estimates the gas cost for a blockchain transaction on the Bob network given sender, recipient, data payload, and value.

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/bob/gas/estimate?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synapse-api-bob-gas-estimator-d39454c6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_2xw4n02ZlK5SYLYvG_EBm

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-bob-gas-estimator-d39454c6 -d '<json body>'
```

Example prompt: Can you estimate the gas needed for a transaction on the Bob network where 0x1234...abcd sends 0.1 ETH to 0xdead...beef with no extra data?

## When to prefer this

Choose this endpoint when you need a quick, pay-per-call gas estimate specifically for the Bob network without maintaining your own RPC node or paying for a full node provider subscription. Ideal for agents that need on-demand, lightweight fee estimation before submitting transactions.

## Known failure modes

- Invalid or malformed Ethereum address in 'to' or 'from' fields returns an error
- Invalid hex string in 'data' field causes a parse error
- Network unavailability or RPC timeout results in a failure response
- Unsupported transaction type or out-of-range value may cause estimation failure
- Missing required fields may return a validation error

## 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 Bob network, enabling callers to budget fees before broadcasting the 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-bob-gas-estimator-d39454c6/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)