# Synapse API — Avalanche Gas Estimator

> Synapse API — Avalanche 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 the gas cost for a transaction on the Avalanche blockchain network given sender, recipient, value, and calldata.

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/avalanche/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-avalanche-gas-estimator-9538048f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_h_WoRySb9g-tHRRuagfq7

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-avalanche-gas-estimator-9538048f -d '<json body>'
```

Example prompt: Estimate the gas needed for a transaction on Avalanche from address 0xAbC...123 to contract 0xDeF...456 with calldata 0xa9059cbb... and a value of 0 AVAX.

## When to prefer this

Use this endpoint when you need a quick, pay-per-call gas estimate specifically for the Avalanche network without managing your own RPC infrastructure. It's ideal for agents that need to pre-check transaction costs before execution, especially in multi-chain workflows where Avalanche is one of many supported chains.

## Known failure modes

- Invalid or malformed Ethereum-style address in 'to' or 'from' fields — returns error
- Malformed hex string in 'data' field — parsing error
- Transaction would revert on-chain (e.g. insufficient balance, failed require) — gas estimation may fail or return error
- Network connectivity issues with Avalanche RPC — timeout or upstream error
- Missing required fields — 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 unit amount for the described Avalanche transaction, allowing the caller to predict fees before broadcasting the transaction to the network.

## 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-avalanche-gas-estimator-9538048f/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)