Check before signing
Limit each call, the total allowance, the rate of spending, and the allowed destinations. Pause new spending with the kill switch.
- Destination allowed
- Price of the call
- Rate of spending
- Allowance remaining
Solana x402 payments · development demo
An allowance for your agent.
Let an agent buy data and services on Solana. Set its spending limits before it signs. See what was paid, what was returned, and what is still locked.
Public devnet proof: $0.03 paid · $0.07 refunded · finalized transaction
A wallet is not a policy
Pay for the work.
Keep control of the spend.
Pay for actual usage
Use exact for a fixed price. Use upto for a metered request with an approved ceiling and a refund of the unused amount.
Keep escrow visible
Open deposits remain committed to the budget. The ledger, channel list, dashboard, and MCP tools show where the money went.
Give an agent room to act.
Keep every payment accountable.
The money model
A deposit is not spare change.
Money in a channel has left the wallet but is not all spent. Wallie counts it as escrow until settlement or recovery establishes the result.
available = min(budget, funded) − spent − reserved − escrowed
A missing receipt does not create a fresh allowance. Recovery records each payment once. If the outcome is uncertain, the deposit stays held. Invalid saved channel state blocks new authorization.
Watch it work
The story. Then the walkthrough.
Narrated demos with captured command output, captions, and downloadable transcripts. The local simulation and the public devnet settlement are identified separately.
3 minute pitch
The problem, the allowance, and the Solana payment proof.
5 minute walkthrough
Exact, metered usage, a refund, a block, and recovery.
Repeatable local demo
One paid call. One refund. One block.
The example agent drives the real MCP protocol. Its exact purchase uses the local practice rail. Its Solana channel purchase builds the transaction format and simulates settlement offline. Neither phase needs keys or moves real funds.
EXACT weather data $0.001 local practice rail BLOCKED enterprise feed $5.00 over the $1 per-call cap UPTO 30 metered rows $0.10 cap offline Solana operator SETTLED actual usage $0.03 REFUNDED unused ceiling $0.07
Run the commands below to inspect the complete output. This is an offline demonstration. The separate transaction below is public devnet evidence.
Independent chain evidence
The devnet transaction is public.
Finalized · no transaction error
- Finalized slot
- 498210157
- To the seller
- 30,000 µUSDC
- Refunded to the buyer
- 70,000 µUSDC
Recorded on 14 September 2026. Devnet USDC is test money.
Read the canary record and command. Live Solana exact through CDP and sustained Solana mainnet traffic are outside this proof.
Run it yourself
Source, tests, and an install path.
Use Node 24 or later for the source demo. Start with the offline flow before connecting a funded wallet.
git clone --branch v0.6.0 --depth 1 https://github.com/fskroes/AllowanceKit.git cd AllowanceKit npm ci npm run demo:mcp npm test npm run build
SDK and CLI
npm install allowance-kit@0.6.0
Add the Solana peers for a live Solana agent. The core runtime keeps optional libraries separate.
Solana setup →MCP server
npx wallie-mcp@0.6.0
The MCP package includes its protocol and chain libraries. A fresh state directory uses practice money.
Client configuration →Hand-in materials
Project description, architecture, proof links, reproduction steps, and scope in one place.
Open the submission pack →Scope and questions
What the evidence covers.
The included MCP demo is offline and uses local settlement. The separate canary uses public Solana devnet and test USDC. Both are labelled in the demo and linked evidence.
The code accepts Solana mainnet with explicit confirmation, but this submission claims public devnet validation. It does not claim a Solana mainnet canary or sustained production traffic.
The runtime keeps the channel committed and reconciles available chain evidence. Recovered payments enter the ledger once. If the outcome is still unknown, the money stays held instead of becoming available to spend again.
The seller pays the transaction fee on the normal sponsored payment path. A buyer that reclaims an abandoned channel needs SOL for its own recovery transactions.
It controls payments routed through Wallie. It does not cap a separate cloud account, a credit card, or transactions that bypass this runtime. Anyone given the wallet key or administrative approval tools must be trusted with that authority.
Yes. The source commands run the offline demo and tests. The canary record provides the public devnet command, ledger amounts, and full transaction link. A fresh live run needs funded devnet wallets.
Give your agent an allowance.
Open source under MIT. Inspect the policy. Run the demo. Follow the money.