PredictIt Signal Monitor Setup Guide

Time: 5 minutes | Difficulty: Easy | Market: Prediction Markets Mode: Signal-only | API: Public REST API (read-only) | Docs: predictit.org/api/marketdata/all

This guide configures a PredictIt signal monitor using the botwir3 runtime. Connect to the public market data API, generate prediction market signals locally, and review them before executing manually on PredictIt.

Signal-only mode

PredictIt does not support automated order placement through an API. The public API provides market data only — current prices, contract details, and market metadata. This guide configures the botwir3 runtime in signal-only mode: the bot monitors pricing data and generates signals. The user reviews the signals and executes manually on PredictIt.

botwir3 does not place orders, bids, or transactions on PredictIt. The user is responsible for all execution decisions.

Before you start

Verify that data access is permitted under PredictIt's current terms of service before deploying. botwir3 provides tools for building structured automation. The user is responsible for compliance with the platform's terms and all applicable regulations.

PredictIt Terms of Service | Last verified: May 2026

What you need

• A PredictIt account (for manual trade execution)
• The botwir3 runtime downloaded and unzipped
• A strategy config file from the builder (signal-only mode)

Step 1: Configure the data source

PredictIt's public API requires no authentication. The /marketdata/all endpoint returns current prices for all active markets.

Create adapter.json in the bot directory:

{
  "adapter": "predictit",
  "mode": "signal_only",
  "data_source": {
    "type": "api",
    "url": "https://www.predictit.org/api/marketdata/all"
  },
  "rate_limit_ms": 60000
}

rate_limit_ms: PredictIt's API is public and rate-limited. 60000ms (1 minute) is a reasonable polling interval. The data updates infrequently — more frequent polling does not yield faster price changes.

No API keys are required. No credentials are stored. botwir3 does not transmit data to any third party.

Step 2: Configure signal output

The bot writes signals to a local file or displays them in the terminal.

{
  "signal_output": {
    "type": "file",
    "path": "./signals/predictit.json"
  }
}

Step 3: Start the monitor

botwir3 start --config my-strategy.json --signal-only

Expected output:

[botwir3] Adapter: predictit
[botwir3] Mode: signal-only
[botwir3] Data source: https://www.predictit.org/api/marketdata/all
[botwir3] Polling interval: 60s
[botwir3] Monitoring...

The runtime evaluates signals against the strategy and logs opportunities. It does not connect to PredictIt for order execution. The gate function compares proposed signals against the configured spec. All signals are recorded in the local ledger.

Reading the signals

[botwir3] Signal: BUY YES | "Will the Fed cut rates in June 2026?" | Price: $0.42 | Model: $0.58
[botwir3] Signal logged to ./signals/predictit.json

The user reviews each signal and decides whether to execute manually on PredictIt. The signal includes the contract name, current market price, and the model's estimated probability.

Why signal-only?

PredictIt provides a read-only public API (/marketdata/all) that returns market prices without authentication. No trading API exists — order placement requires the PredictIt website. The platform also has a $850 maximum investment per contract. The user is responsible for understanding position limits and executing trades manually.

Related guides

• Kalshi Setup Guide — prediction markets, full automation, CFTC-regulated
• Polymarket Setup Guide — prediction markets, full automation, CLOB API
• Manifold Markets Setup Guide — prediction markets, full automation, play-money

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