# Synapse API — SEI Gas Estimation

> Synapse API — SEI Gas Estimation 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 2026-10-15).

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

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/sei/gas/estimate?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synapse-api-sei-gas-estimation-613a9dff
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_RQymtSvPeUc5ESWUKubAL

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-sei-gas-estimation-613a9dff -d '<json body>'
```

Example prompt: Estimate the gas needed for a SEI transaction from 0xAbC...123 to 0xDeF...456 with a value of 1000000usei and calldata 0xabcdef.

## When to prefer this

Use this endpoint when you need a quick, pay-per-call gas estimate specifically for the SEI blockchain network without running your own RPC node. Prefer it over generic blockchain APIs when working within the SEI ecosystem, or when cost-per-call pricing is preferable to subscription models.

## Known failure modes

- Invalid address format in 'to' or 'from' fields returns a 400 or validation error
- Malformed hex in 'data' field causes parsing failure
- SEI network RPC node unavailable returns a 503 or timeout error
- Missing required fields may return incomplete estimates or errors
- Value field with unsupported format may cause computation failure

## 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 (typically as a numeric value representing gas units or fee in the SEI network's denomination) for the described transaction, allowing callers to set appropriate gas limits or display fee previews before submission.

## 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-sei-gas-estimation-613a9dff/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)