> ## Documentation Index
> Fetch the complete documentation index at: https://docs.blink15.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Core Concepts

> How prediction markets, binary tokens, and settlement work on Blink

## Binary Prediction Markets

Blink runs prediction markets on crypto price movements using Pyth oracle feeds. Each market is a simple question:

> "Will BTC's price be **higher** or **lower** at the end of this market window than it was at the start?"

Two outcome tokens are created for each market:

* **YES token** (UP) — pays \$1.00 if the price closes higher
* **NO token** (DOWN) — pays \$1.00 if the price closes lower

Token prices reflect the market's probability estimate. If UP trades at \$0.65, the market thinks there's a \~65% chance the stock goes up.

## Market Lifecycle

```
┌──────────┐    ┌──────────┐    ┌──────────┐    ┌──────────┐
│ Created  │───▶│  Active  │───▶│ Resolved │───▶│ Redeemed │
│          │    │ (Trading)│    │ (Outcome)│    │ (Payout) │
└──────────┘    └──────────┘    └──────────┘    └──────────┘
                  Trading          Automatic       Automatic
```

1. **Created** — Market window scheduled
2. **Active** — Trading open. Buy/sell YES and NO tokens.
3. **Resolved** — Window closes. Pyth oracle determines outcome.
4. **Redeemed** — Winning tokens automatically redeemed for \$1.00 USDC each.

## Token Pricing

Prices are always between $0.01 and $0.99:

| YES Price | NO Price | Market View                     |
| --------- | -------- | ------------------------------- |
| \$0.80    | \$0.20   | 80% probability price goes up   |
| \$0.50    | \$0.50   | Equal probability (coin flip)   |
| \$0.30    | \$0.70   | 70% probability price goes down |

YES + NO always sums to \~\$1.00 (minus spread). This is enforced by the MINT/MERGE mechanism:

* **MINT**: Buy YES at $0.60 + Buy NO at $0.40 = \$1.00 → 1 YES + 1 NO minted
* **MERGE**: Sell YES at $0.60 + Sell NO at $0.40 = 1 YES + 1 NO burned → \$1.00 returned

## Order Types

| Type                                | Behavior                                                                         |
| ----------------------------------- | -------------------------------------------------------------------------------- |
| **GTC** (Good Till Cancel)          | Rests on the book until filled or cancelled. Default.                            |
| **GTD** (Good Till Date)            | Rests until the specified expiration time.                                       |
| **FOK** (Fill or Kill)              | Must fill entirely or is rejected. No partial fills.                             |
| **IOC / FAK** (Immediate or Cancel) | Fills what it can immediately, cancels the rest. Called `FAK` in the Python SDK. |

**Post-only**: Add `post_only=True` to reject orders that would match immediately. Useful for market makers who want to provide liquidity, not take it.

## Amount Encoding

All amounts use 6 decimal places internally (matching USDC's 6 decimals):

| Human Value | Raw Value   | Meaning               |
| ----------- | ----------- | --------------------- |
| 1 USDC      | 1,000,000   | One dollar            |
| 100 tokens  | 100,000,000 | One hundred contracts |
| \$0.50      | 500,000     | Fifty cents           |

**The SDK handles all conversions.** Pass human-readable numbers (`price=0.50`, `size=20`) and the SDK converts to raw amounts.

For BUY orders:

* `makerAmount` = size × price × 1,000,000 (USDC you pay)
* `takerAmount` = size × 1,000,000 (tokens you receive)

For SELL orders:

* `makerAmount` = size × 1,000,000 (tokens you give)
* `takerAmount` = size × price × 1,000,000 (USDC you receive)

## Authentication

Blink uses the same two-level auth as Polymarket:

### Level 1 — EIP-712 (Wallet Proof)

Used once to create API credentials. Your wallet signs a typed data message proving ownership. The private key never leaves your machine.

### Level 2 — HMAC-SHA256 (Trading)

Used for every trading request. Four headers are required:

| Header             | Value                                                                     |
| ------------------ | ------------------------------------------------------------------------- |
| `BLINK-API-KEY`    | UUID from credential creation                                             |
| `BLINK-SIGNATURE`  | HMAC-SHA256 of `{timestamp}{METHOD}{path}{body}`, URL-safe base64 encoded |
| `BLINK-TIMESTAMP`  | Unix seconds                                                              |
| `BLINK-PASSPHRASE` | Passphrase from credential creation                                       |

The SDK handles all signing automatically.

## Settlement

Every matched trade is settled on-chain via the Base network:

1. Order matches in the matching engine (\~1ms)
2. Settlement TX submitted to Base (\~100ms)
3. TX confirmed on-chain (\~2 seconds)
4. CTF tokens minted/transferred to wallets
5. Activity feed updated with on-chain TX hash

Settlement is fully automatic. You don't need to claim or withdraw — tokens appear in your wallet.

## Resolution and Redemption

When a market's window closes:

1. **Pyth oracle** provides the closing price
2. **Adapter contract** compares open vs close price → determines UP or DOWN outcome
3. **CTF contract** sets payout ratios (winning side = $1.00, losing side = $0.00)
4. **Auto-redemption** burns winning tokens and sends USDC to holders
5. All happens typically within 30–60 seconds of market close

## WebSocket Channels

Three real-time channels for different use cases:

| Channel      | URL     | Auth      | Use Case                                   |
| ------------ | ------- | --------- | ------------------------------------------ |
| `/ws/market` | Public  | None      | Orderbook snapshots, trades, market events |
| `/ws/price`  | Public  | None      | Pyth oracle price ticks                    |
| `/ws/user`   | Private | API creds | Fills, cancels, balance updates, positions |