Quick start

kawasekit moves agents from a settled JPYC payment on Polygon Amoy in under ten minutes, using only a ZeroDev project, an owner private key, and the public Polygon Amoy faucet for JPYC.

This walkthrough gets you to a working setup. The deeper examples (agent paywall, observability) build on the same primitives.

Prerequisites

• Node 22+
• pnpm 11+
• A burner Ethereum private key — use a fresh one for testnet, never an owner key that holds real funds
• A ZeroDev project ID
• Polygon Amoy POL from the official faucet
• Polygon Amoy JPYC from the JPYC faucet

Caution

kawasekit is pre-alpha. The first npm publish (kawasekit@0.1.0-alpha) is in preparation. For now, clone the repository and use the workspace directly — the API surface is the same as what will publish to npm.

Steps

1. Clone the repository

   git clone https://github.com/k0yote/kawasekit
   cd kawasekit
   pnpm install
   pnpm --filter kawasekit build

2. Scaffold a .env

   pnpm cli init
   cp .env.example .env

   Open .env and fill in OWNER_PRIVATE_KEY (the burner key) and ZERODEV_PROJECT_ID.

3. Compute the smart-account address

   pnpm cli account create --chain polygonAmoy

   You will see something like:

   Chain:                  Polygon Amoy testnet (80002)
   Owner (EOA):            0x2f5eb6A1...
   Smart account address:  0xdbe30607...

   The smart account is a counterfactual address at this point — it exists deterministically based on your owner key but has not been deployed on-chain. The first UserOp deploys it via the paymaster.

4. Fund the smart account

   Send Polygon Amoy JPYC to the smart account address from step 3:

   • https://faucet.jpyc.co.jp/

   You only need 1 JPYC for the rest of this tutorial.

5. Issue a session key

   The session key is what an agent holds. The owner controls revocation; the session key is bounded by an on-chain daily-limit policy.

   pnpm cli session-key issue \
     --chain polygonAmoy \
     --ephemeral-session \
     --max-per-tx 1 \
     --max-per-day 10 \
     --output envelope.json

   --ephemeral-session generates a fresh session-key private key for this run. The key is printed at the end of the command — save it now, it is not stored to disk.

6. Transfer JPYC via the smart account

   The owner can transfer JPYC directly through the smart account (the session-key path lives in the agent example):

   pnpm cli transfer \
     --chain polygonAmoy \
     --amount 0.001

   The output prints the bundler tx hash and a Polygonscan link. Open it to see your first kawasekit-driven JPYC transfer settle on Polygon Amoy.

What just happened

• kawasekit cli account create derived a Kernel v3.1 smart account counterfactually from your owner key. No on-chain action yet.
• kawasekit cli session-key issue built a session-key envelope — a portable JSON document the agent will use to restore the smart-account client without ever seeing the owner key.
• kawasekit cli transfer broadcast a sponsored UserOp that calls JPYC.transfer() from the smart account. The paymaster (ZeroDev) paid POL for gas.

The same primitives compose into:

• An x402 paywall — see Agent paywall.
• Observability — wire kawasekit/observability/prometheus to any kawasekit surface and the dashboards fill in. See Observability.

Next steps

• Try the agent paywall example — an agent that pays for a weather API call-by-call.
• Read the CLI reference for the full command surface.
• Read the threat model before you take this to mainnet.

Going to mainnet

Every command that touches a network takes --chain polygonAmoy (testnet) or --chain polygon (mainnet). Mainnet broadcasts additionally require KAWASEKIT_ALLOW_MAINNET=1 in the environment. Set this only when you intend to spend real JPYC + real POL. Plan to start with a 0.001 JPYC gradual rollout before scaling.

The v0.1.0 release notes will record the first mainnet broadcast tx URLs for traceability.