Polkadot/Substrate Extrinsics Debugging Toolkit

A comprehensive CLI tool for building, decoding, and analyzing Polkadot/Substrate extrinsics.

Quick Start

# Install dependencies
bun install

# Show available commands
bun cli.ts help

# Add a new chain
bunx papi add <chain> -n <name>

Key Features

• Build & decode extrinsics
• Compare two extrinsics side-by-side
• Query fees for calls and extrinsics
• Inspect blocks, storage, pallets, and types
• SCALE encoding utilities

Common Commands

# Decode an extrinsic
bun cli.ts decode <extrinsic-hex>

# Compare two extrinsics
bun cli.ts compare <hex1> <hex2>

# Query call fees
bun cli.ts query-fees --address <address> --call <call-hex>

# Get block info
bun cli.ts get-block --hash <block-hash>

# List available pallets
bun cli.ts list-pallets

Chain Configuration

Adding a New Chain

Use the add-chain command:

bun cli.ts add-chain \
  --name polkadot \
  --ws-url wss://rpc.polkadot.io \
  --display-name "Polkadot Mainnet" \
  --set-default

This automatically:

• Adds the chain to .papi/polkadot-api.json
• Updates chains.json with the chain configuration
• Optionally sets it as the default chain

Options:

• --name: Chain identifier used in commands (required)
• --ws-url: WebSocket RPC endpoint (required)
• --display-name: Human-readable name (optional, defaults to name)
• --papi-key: PAPI descriptor key (optional, defaults to name)
• --set-default: Make this the default chain (optional)

Documentation

See AGENTS.md for complete CLI reference.