# Lazareus

> Solana network and validator health checks, built for AI agents. Every
> endpoint answers one simple question in a few hundred milliseconds — no
> dashboard, no account, no subscription. Pay per call, on Solana, via x402.

Lazareus is not a dashboard. It's an API designed to be called by AI agents
before they act — before delegating stake, before executing a
timing-sensitive transaction. Responses are small, fast, and structured for
machine consumption first (a `format=llm` mode is also available for a
natural-language sentence instead of JSON).

## Access

- Human docs: https://lazareus.xyz/docs.html
- MCP server (Streamable HTTP): https://lazareus.xyz/mcp
- REST base URL: https://lazareus.xyz

## Payment

- Protocol: x402 (HTTP 402 Payment Required)
- Network: Solana (currently devnet — see /docs.html for current status)
- Currency: USDC
- Price: $0.001 per call, no account or subscription required
- On an unpaid request, the API responds `402` with a `PAYMENT-REQUIRED`
  header describing the exact payment terms (amount, asset, payTo,
  network). Sign and retry with a `PAYMENT-SIGNATURE` header to get the
  real response.

## Endpoints

### GET /is_validator_delinquent

Tells you whether a given Solana validator is currently delinquent (behind
on the network, not voting correctly, absent from the `current` vote
accounts list). Useful for an agent managing stake that needs to decide
where to delegate, or whether to withdraw urgently.

Query parameters:
- `address` (required) — the validator's vote account address
- `format=llm` (optional) — returns a natural-language sentence instead of JSON

Example:
```
GET https://lazareus.xyz/is_validator_delinquent?address=so1arJJbp9sis5XpovLyjTZPk8bDjfs37Meghi5wXbu
```

Response:
```json
{
  "address": "so1arJJbp9sis5XpovLyjTZPk8bDjfs37Meghi5wXbu",
  "delinquent": false,
  "found": true,
  "checked_at": "2026-08-06T15:24:26.014Z"
}
```

### GET /is_network_degraded

Tells you whether the Solana network is currently degraded — combining
average slot time, % of delinquent stake, median prioritization fee
(congestion signal), and skipped-slot rate (block production health).
Useful before executing a timing-sensitive transaction.

Query parameters:
- `format=llm` (optional) — returns a natural-language sentence instead of JSON

Example:
```
GET https://lazareus.xyz/is_network_degraded
```

Response:
```json
{
  "degraded": false,
  "reasons": [],
  "metrics": {
    "avg_slot_time_ms": 421.2,
    "delinquent_stake_pct": 0.06,
    "median_prioritization_fee_microlamports": 0,
    "skip_rate_pct": 0
  },
  "thresholds": {
    "slot_time_degraded_ms": 600,
    "delinquent_stake_degraded_pct": 10,
    "prioritization_fee_degraded_microlamports": 10000,
    "skip_rate_degraded_pct": 5
  },
  "checked_at": "2026-08-06T18:45:34.680Z"
}
```

## Errors

Both endpoints share a standard error shape:
```json
{ "error": { "code": "invalid_address", "message": "Invalid address" } }
```
Known codes: `missing_parameter`, `invalid_address`, `internal_error`.

## Free, unpaid endpoints

- `GET /health` — liveness check
- `GET /stats` — total calls served, average response time
- `GET /uptime` — hourly uptime history for both endpoints, last 30 days

## MCP tools

The MCP server at `https://lazareus.xyz/mcp` (Streamable HTTP transport)
exposes the same two checks as tools:

- `is_validator_delinquent(address)`
- `is_network_degraded()`

Same underlying logic and response shape as the REST endpoints above.