# Synapse API — SEI Latest Block Fetcher

> Synapse API — SEI Latest Block Fetcher 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 2026-09-13).

Fetches the latest block data from the SEI blockchain network

## Facts

- Endpoint: POST https://synapse-api-brown.vercel.app/api/sei/block/latest
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synapse-api-sei-latest-block-fetcher-8f6b7783
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9nngJZnt7DwsS_fIWkfqn

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-latest-block-fetcher-8f6b7783 -d '<json body>'
```

Example prompt: What is the latest block on the SEI blockchain right now? Fetch the current block height and timestamp for me.

## When to prefer this

Choose this endpoint when you need real-time latest block data specifically from the SEI blockchain network and want pay-per-call pricing via x402 without a subscription. Prefer this over self-hosted RPC nodes when you need a managed, low-friction option for SEI chain queries.

## Known failure modes

- Network timeout if SEI RPC node is unavailable
- Invalid or empty body object may cause request rejection
- SEI node sync lag may return a slightly stale block
- Rate limiting if called too frequently without payment
- HTTP 402 if payment header is missing or insufficient

## 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 the latest block data from the SEI blockchain, including block number (height), block hash, timestamp, and potentially transaction count or other block-level metadata.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "$schema": "https://json-schema.org/draft/2020-12/schema",
     "properties": {},
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST",
      "PUT",
      "PATCH"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synapse-api-sei-latest-block-fetcher-8f6b7783/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)