# Fanfare MLB Late-Swap Monitor

> Fanfare MLB Late-Swap Monitor is a paid API for AI agents from fanfare.run, paid per call via x402, $0.03/call, status unknown (last checked 2026-09-15).

Returns MLB players whose lineup status or batting order changed within a recent time window, optimized for frequent polling during pre-game windows for daily fantasy late-swap decisions.

## Facts

- Endpoint: GET https://fanfare.run/v1/fantasy/mlb/late-swap
- Price: $0.03/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fanfare-mlb-late-swap-monitor-9a2984d0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_2SBEqx6pA926w_cdYM6OE

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 fanfare-mlb-late-swap-monitor-9a2984d0
```

Example prompt: Check for any MLB lineup or batting order changes since 11:30 AM UTC today, June 15, 2025 — I need to know who got scratched or moved so I can make late swaps before lock.

## When to prefer this

Use this endpoint when you need to detect real-time MLB lineup changes in a tight polling loop (every 60 seconds) during the pre-game window for daily fantasy late-swap decisions. It is purpose-built for cheap, frequent polling at $0.03/call and is more efficient than a full slate bundle when you only need delta changes since a recent timestamp.

## Known failure modes

- Missing required 'date' parameter returns a 400 error
- Invalid date format (not YYYY-MM-DD) causes a parsing error
- 'since' timestamp in wrong format (not ISO-8601 UTC) returns an error
- No changes detected in window returns an empty result set
- Date in the distant past or future with no game data may return empty or error
- Payment not included or insufficient returns 402 Payment Required

## How this service works

Tight-window MLB poll target: players whose lineup status / batting order changed since `since` (default now-900s). Cheap to poll every 60s through the pre-game window. Params: date, since (ISO-8601 UTC).

## Output

A list of MLB players whose lineup status or batting order position changed after the specified 'since' timestamp on the given date, including player identifiers and details about what changed — suitable for triggering late-swap decisions in daily fantasy contests.

## Example request

```json
{
 "input": {
  "type": "http",
  "method": "GET",
  "queryParams": {
   "date": "2025-06-15",
   "since": "2025-06-15T11:30:00Z"
  }
 }
}
```

## 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"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "date"
     ],
     "properties": {
      "date": {
       "type": "string",
       "description": "Calendar date YYYY-MM-DD"
      },
      "since": {
       "type": "string",
       "description": "ISO-8601 UTC; returns changes after this (default now-900s)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fanfare-mlb-late-swap-monitor-9a2984d0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fanfare.run](https://www.zero.xyz/host/fanfare.run/llms.txt)