Kora Gasless Relay

Fee-less transactions via the Kora paymaster

Kora is a Rust-based gasless relay that sponsors network fees on behalf of agent wallets. With Kora running, agent wallets never need SOL for gas — they only need USDC for x402 payments.

Why Kora?

Without Kora, every agent wallet needs SOL for transaction fees. This creates friction:

• New wallets must be funded with SOL before they can do anything
• Agents need to manage two balances (SOL for gas + USDC for payments)
• Small SOL balances can get depleted, causing unexpected failures

With Kora, the Kora signer pays all gas fees. Agent wallets are truly gasless.

Funding Breakdown

Account	What it pays	How to fund
Kora signer	SOL network fees for every agent transaction	solana airdrop (devnet) or transfer SOL (mainnet)
Agent wallets	Nothing — completely gasless	No SOL needed
Master wallet	SOL for account rent (e.g., new ATA creation at ~0.002 SOL)	Configured in .env

Setup

1. Install Kora CLI

   cargo install kora-cli
   
2. Export Your Keypair

   Use a wallet you already control (e.g., Phantom) so you own the Kora signer address.

   From Phantom: Settings → Security & Privacy → Export Private Key

   Convert the base58 key to JSON format:

   node scripts/phantom-to-kora.mjs YOUR_PHANTOM_BASE58_KEY
   

   This writes kora/kora-signer.json.

   Delete the base58 key from your terminal history after running this command. The kora/kora-signer.json file is .gitignored and will never be committed.

3. Fund the Signer

   solana airdrop 2 <YOUR_PUBLIC_KEY> --url devnet
   

   A 2 SOL airdrop gives you ~400,000 transactions worth of gas.

4. Configure Environment

   .env

   KORA_RPC_URL=http://localhost:8080
   KORA_SIGNER_PRIVATE_KEY=kora/kora-signer.json
   
5. Start the Kora Node

   kora --config kora/kora.toml --rpc-url https://api.devnet.solana.com rpc start --signers-config kora/signers.toml
   

   Expected output: INFO kora_lib::rpc_server::server: RPC server started on 0.0.0.0:8080

6. Verify Connectivity

   curl -s -X POST http://localhost:8080 \
     -H "Content-Type: application/json" \
     -d '{"jsonrpc":"2.0","id":1,"method":"getConfig","params":[]}'
   

Configuration Files

File	Purpose
kora/kora.toml	Node endpoints and general configuration
kora/signers.toml	Signing permissions, limits, and allowed addresses
kora/kora-signer.json	The fee-payer keypair (.gitignored)

Audit Trail

When Kora sponsors a transaction, the audit log records:

• gasless: true
• feePayer: "kora"
• The Kora signer’s public key

This distinction is visible in the audit://wallet-logs resource and the CLI dashboard.