Flap Token Indexer

An example indexer for Flap Protocol that indexes token information and provides a REST API for querying tokens and getting quotes.

Feature

• Indexes token creation events and updates from the Flap Portal Contract
• Tracks token bonding curve parameters, circulating supply, and DEX listing status
• Provides REST API endpoints for token information and buy/sell quotes
• Supports data remediation for tokens created before the indexer start block
• Uses SQLite database for persistent storage

Setup

1. Install dependencies:

npm install

2. Create a .env file based on .env.example:

cp .env.example .env

3. Update the .env file with your configuration:

   • PORTAL_CONTRACT_ADDRESS: The address of the Flap Portal Contract
   • RPC_URL: RPC endpoint for the blockchain
   • DEFAULT_START_BLOCK: Block number to start indexing from
   • Other configuration options as needed

4. Build the project:

npm run build

5. Start the indexer:

npm start

For development, you can run directly with ts-node:

npm run dev

API Endpoints

Get Token Information

GET /token/:address&try_remediation=<true|false> 

And optionally with query parameter:

• try_remediation (optional): Boolean flag. If true, the API will attempt to fetch token data from the blockchain if the token is not found in the database. Note: The call may revert if the token doesn't exist on-chain.

Returns comprehensive token information including:

• Basic token details (name, symbol, creator, etc.)
• Bonding curve parameters (r, h, k)
• Current circulating supply and price
• DEX listing status and progress

Get Buy/Sell Quote

GET /quote?token=<address>&side=<buy|sell>&input_amount=<amount>&try_remediation=<true|false>

Parameters:

• token: Token address
• side: Either "buy" or "sell"
• input_amount: Amount to buy with (for buy) or amount to sell (for sell)
• try_remediation (optional): Boolean flag. If true, the API will attempt to fetch token data from the blockchain if the token is not found in the database. Note: The call may revert if the token doesn't exist on-chain.

Returns the estimated output amount for the trade including the quote token address.

Health Check

GET /health

Returns server status and timestamp.

Configuration

The indexer is configured via environment variables in the .env file:

• PORTAL_CONTRACT_ADDRESS: Portal contract address (required)
• CHAIN_NAME: Blockchain name (default: "morph")
• RPC_URL: RPC endpoint URL
• DEFAULT_START_BLOCK: Starting block number for indexing
• INDEX_BATCH_SIZE: Number of blocks to process per batch (default: 200)
• INDEX_INTERVAL: Milliseconds between batches (default: 200)
• BUY_FEE_RATE: Buy fee in basis points (default: 250 = 2.5%)
• SELL_FEE_RATE: Sell fee in basis points (default: 250 = 2.5%)
• PORT: API server port (default: 3000)
• DATABASE_FILE: SQLite database file (default: "tokens.db")

Database Schema

The indexer uses SQLite with two main tables:

tokens

Stores token information including bonding curve parameters, supply, and status.

meta

Stores indexer metadata, primarily the last processed block number.

License