# Synapse API — Mantle Gas Estimator

> Synapse API — Mantle 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 costs for a transaction on the Mantle blockchain network given sender, recipient, data, and value.

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/mantle/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-mantle-gas-estimator-73db29c0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dA_oH2NJN9jyVc7ZQFc9-

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-mantle-gas-estimator-73db29c0 -d '<json body>'
```

Example prompt: Estimate the gas needed for a Mantle network transaction from 0xAbC...123 to 0xDeF...456 with calldata 0xa9059cbb... and value 0 — I want to know how many gas units this will consume before I send it.

## When to prefer this

Choose this endpoint when you need a fast, pay-per-call gas estimate specifically for the Mantle L2 network without managing your own RPC node. Ideal when building agents that need pre-flight cost validation before submitting transactions on Mantle, or when you want a lightweight serverless gas oracle without provisioning infrastructure.

## Known failure modes

- Invalid or malformed address in 'to' or 'from' fields — returns error or rejects request
- Invalid calldata hex string causes estimation failure
- Transaction would revert on-chain — gas estimation may fail or return an error indicating revert
- Network connectivity issues to Mantle RPC nodes — timeout or 503 error
- Missing required fields result in 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 Mantle network, allowing the caller to 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-mantle-gas-estimator-73db29c0/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)