space.skywatch

One call → what's notable in YOUR sky right now, for a lat/lon. Synthesizes three sources: (1) the live almanac — sun up/down, moon phase + illumination, and which of the 7 naked-eye planets are currently above your horizon with their altitude/azimuth/magnitude; (2) near-Earth asteroid close approaches over the next 7 days (designation, date, distance in lunar distances); and (3) the ISS — its current sub-point, and whether it is above your horizon right now with look angles. Each section reports found/error independently. The "is it dark, what's up, anything passing" digest for stargazers and astrophotographers. For the raw almanac alone see /api/space/sky-tonight.

price

$0.0029 USDC per call

method

GET/api/space/skywatch

payment

x402 v2 · USDC on Base (EIP-3009) or Solana (SPL transfer)

auth

None. Sign the payment, retry with PAYMENT-SIGNATURE.

tier

Tier 0 — no paid upstream

Parameters

Name	Type	Description
`lat`required	number	min -90 · max 90
`lon`required	number	min -180 · max 180
`altitudeM`	number	min -500 · max 9000

Code samples

cURLbash

# 1. Probe with no auth → 402 envelope with PaymentRequirements
curl -sS 'https://2s.io/api/space/skywatch?lat=-90&lon=-180&altitudeM=0'

# 2. Sign + retry with PAYMENT-SIGNATURE:
curl -sS 'https://2s.io/api/space/skywatch?lat=-90&lon=-180&altitudeM=0' \
  -H 'PAYMENT-SIGNATURE: <base64-json-payload>'

# Or use the canonical runner (handles probe → sign → retry):
#   EVM_PRIVATE_KEY=0x... node --env-file=.env.local \
#     --experimental-strip-types scripts/x402-pay.ts \
#     'https://2s.io/api/space/skywatch?lat=-90&lon=-180&altitudeM=0'

TypeScript / Node — @2sio/sdktypescript

import { TwoS } from '@2sio/sdk'

const client = new TwoS({
  privateKey: process.env.EVM_PRIVATE_KEY as `0x${string}`,
})

const result = await client.space.skywatch({
  "lat": -90,
  "lon": -180,
  "altitudeM": 0
})

console.log('endpoint:', result.endpoint)
console.log('cost:', result.costUsd, 'USDC')
console.log('tx:', result.settlement?.txHash)
console.log('data:', result.data)

Python — 2siopython

import os
from twosio import TwoS

client = TwoS(private_key=os.environ["EVM_PRIVATE_KEY"])

result = client.space.skywatch(lat=-90, lon=-180, altitudeM=0)

print("endpoint:", result.endpoint)
print("cost:", result.cost_usd, "USDC")
print("tx:", (result.settlement or {}).get("tx_hash"))
print("data:", result.data)

MCP — Claude Desktop / AgentKit / any MCP hostjson

// 1. Add @2sio/mcp to your MCP host config (Claude Desktop example below).
//    EVM_PRIVATE_KEY funds x402 payments per call.

// claude_desktop_config.json
{
  "mcpServers": {
    "2sio": {
      "command": "npx",
      "args": ["-y", "@2sio/mcp"],
      "env": { "EVM_PRIVATE_KEY": "0x..." }
    }
  }
}

// 2. Once the server is running, agents call this tool via standard MCP:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "space.skywatch",
    "arguments": {
      "lat": -90,
      "lon": -180,
      "altitudeM": 0
    }
  }
}

Response

Field	Type	Description
`at`	string
`observer`	object
`sky`	object
`closeApproaches`	object
`iss`	object
`sources`	array

Example response datajson

{
  "at": "example",
  "observer": {
    "lat": 1,
    "lon": 1,
    "altitudeM": 1
  },
  "sky": {
    "isDark": false,
    "sun": {},
    "moon": {},
    "planetsUp": [
      {}
    ]
  },
  "closeApproaches": {
    "found": false,
    "error": "example",
    "count": 1,
    "approaches": [
      {}
    ]
  },
  "iss": {
    "found": false,
    "error": "example",
    "aboveHorizon": false,
    "geodetic": {},
    "look": {}
  },
  "sources": [
    {}
  ]
}

Discovery

/api/directory — full catalog of every endpoint
/openapi.json — OpenAPI 3.1 spec (per-op x-payment-info, x402Payment security)
/.well-known/x402 — machine-readable service descriptor for x402-aware crawlers
/.well-known/mcp/server-card.json — MCP SEP-1649 server card
/llms.txt — plain-text manifest for LLM ingestion

2s.io is x402-native. Every call is paid per-request from a USDC-funded EVM wallet on Base — no signup, no API keys, no monthly fees. Source code: github.com/2s-io/sdk.