# Synapse API — Celo Gas Estimator

> Synapse API — Celo 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 Celo blockchain given sender, recipient, data payload, and value

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/celo/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-celo-gas-estimator-4bad82a0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_aZ-hG7GUk9fbKVCB_NV9y

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-celo-gas-estimator-4bad82a0 -d '<json body>'
```

Example prompt: Estimate the gas needed for a Celo transaction from 0xSenderAddress to 0xRecipientAddress with a value of 1 CELO and no calldata, so I know the fee before I send it.

## When to prefer this

Use this endpoint when you need to estimate gas costs specifically on the Celo blockchain before committing a transaction. It is purpose-built for Celo and paid per-call via x402, making it ideal for lightweight, on-demand pre-flight checks in agent workflows without requiring a full Celo node or web3 library.

## Known failure modes

- Invalid or malformed Ethereum-style address returns a 400 error
- Malformed hex data payload causes parsing error
- Celo RPC node unavailable leads to 503 or timeout
- Insufficient input parameters may return an error or inaccurate estimate
- Transaction that would revert on-chain may return an error or inflated estimate

## 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 Celo transaction, indicating approximately how much gas will be consumed if the transaction is executed with the provided parameters.

## 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-celo-gas-estimator-4bad82a0/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)