# x402-factory Prediction Market Delta Feed

> x402-factory Prediction Market Delta Feed is a paid API for AI agents from x402-factory.com, paid per call via x402, $0.015/call, status unknown (last checked 2026-09-14).

Returns only the materially-moved prediction markets in a given category since a keyset cursor, enabling efficient polling for probability changes

## Facts

- Endpoint: GET https://x402-factory.com/v1/board/:category/delta
- Price: $0.015/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-factory-prediction-market-delta-feed-dea22d5a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NNb6BVb2cHgaS9G8uuqsi

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 x402-factory-prediction-market-delta-feed-dea22d5a
```

Example prompt: Show me only the prediction markets in the crypto category that have moved since my last check — use cursor abc123xyz from my previous call to get the delta.

## When to prefer this

Use this endpoint when you need efficient incremental polling of prediction market probability changes for a specific category, rather than fetching the full board on every call. It is ideal for agents that need to react to probability movements without re-processing unchanged markets. Prefer the free sibling board endpoint to bootstrap state, then switch to this delta endpoint for ongoing monitoring.

## Known failure modes

- Invalid or expired cursor returns an error or resets the cursor
- Unknown category enum value returns a 400 or 422 validation error
- Payment failure (402) if USDC balance is insufficient
- No markets changed since cursor returns empty rows array with same next_cursor
- Rate limiting if polling too aggressively

## How this service works

Only the materially-moved markets in the segment changed since your cursor (delt — Keyset delta of /v1/board/:category: pass since=<next_cursor from your last call> and get only the materially-moved markets in the segment added or changed after it, plus changed_count and a new next_cursor. Omit since once to bootstrap. Cursors are stable across restarts. Poll the free sibling…

## Output

A JSON object containing: rows (array of changed markets with slug, question, category, current probability p, previous probability prev_p, probability delta, and changed_at timestamp), changed_count (integer number of changed markets), next_cursor (opaque string for the next poll), and as_of (timestamp of the response).

## 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"
     ],
     "type": "string"
    },
    "pathParams": {
     "type": "object",
     "required": [
      "category"
     ],
     "properties": {
      "category": {
       "enum": [
        "politics-us",
        "politics-world",
        "economics",
        "fed",
        "crypto",
        "sports-nfl",
        "sports-nba",
        "sports-mlb",
        "sports-soccer",
        "entertainment",
        "climate",
        "science-tech"
       ],
       "type": "string"
      }
     }
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "since": {
       "type": "string",
       "maxLength": 300,
       "minLength": 4,
       "description": "Opaque cursor from a previous next_cursor; omit once to bootstrap a cursor at now"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "data",
      "meta"
     ],
     "properties": {
      "data": {
       "type": "object",
       "required": [
        "rows",
        "changed_count",
        "next_cursor",
        "as_of"
       ],
       "properties": {
        "rows": {
         "type": "array",
         "items": {
          "type": "object",
          "required": [
           "slug",
           "question",
           "category",
           "p",
           "prev_p",
           "delta",
           "changed_at"
          ],
          "properties": {
           "p": {
            "type": "number",
            "maximum": 1,
            "minimum": 0
           },
           "slug": {
            "type": "string"
           },
           "delta": {
            "type": "number"
           },
           "prev_p": {
            "type": "number",
            "maximum": 1,
            "minimum": 0
           },
           "category": {
            "type": "string"
           },
           "question": {
            "type": "string"
           },
           "changed_at": {
            "type": "string"
           }
          },
          "additio
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-factory-prediction-market-delta-feed-dea22d5a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-factory.com](https://www.zero.xyz/host/x402-factory.com/llms.txt)