> ## Documentation Index
> Fetch the complete documentation index at: https://docs.hypedexer.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Testnet — HIP-4 Prediction Markets

> Indexed data for Hyperliquid HIP-4 prediction markets on testnet

<Note>
  HIP-4 is currently **testnet-only**. These endpoints are not available on mainnet yet.
</Note>

## What is HIP-4?

HIP-4 introduces on-chain prediction markets (outcome trading) on Hyperliquid. Users can trade binary outcomes (Yes/No) on questions like "BTC above 66220 on Mar 29?" or multi-outcome questions like "What will Hypurr eat the most of in Feb 2026?"

## Base URL

[https://api.hypedexer.com/testnet](https://api.hypedexer.com/testnet)

## Key concepts

| Concept                      | Description                                                           |
| ---------------------------- | --------------------------------------------------------------------- |
| **Market** (`#` coin)        | A prediction market outcome (e.g. `#24371` = "BTC above 66220")       |
| **Outcome Token** (`@` coin) | The spot-tradeable token for an outcome (e.g. `@10` = CHUTORO)        |
| **Question**                 | Groups related outcomes (e.g. question 1 → Akami, Otoro, Canned Tuna) |
| **Settlement**               | Resolution of a market (settle\_fraction: 0 = No, 1 = Yes)            |

## Fee behavior

<Warning>
  Prediction market fills (`#` coins) currently have **fee = 0** on testnet — the SetOutcomeFeeScale governance action has not been activated.
</Warning>

Outcome token fills (`@` coins) are charged **normal spot fees** (taker/maker rates). The `fee_usdc` field normalizes fees to USD equivalent.

## Quick examples

<CodeGroup>
  ```bash Markets for a question theme={null}

  curl -X 'GET' \
    'https://api.hypedexer.com/testnet/hip4/markets?question_id=1' \
    -H 'accept: application/json' \
    -H 'X-API-Key: YOUR_API_KEY'

  curl -X 'GET' \
    'https://api.hypedexer.com/testnet/hip4/fills?user=0x079f56bfd27f71cbd278c27c7b121e7ef180a5be' \
    -H 'accept: application/json' \
    -H 'X-API-Key: YOUR_API_KEY'

  curl -X 'GET' \
    'https://api.hypedexer.com/testnet/hip4/fees?user=0x1733d1945f023dfece04363d26f032ef069accdc' \
    -H 'accept: application/json' \
    -H 'X-API-Key: YOUR_API_KEY'
    
  ```
</CodeGroup>