three.ws — x402 for VS Code

Browse the x402 bazaar, decode 402 Payment Required challenges, and pay per call for paid APIs and MCP tools in USDC or $THREE on Solana, or USDC on Base and other EVM chains, without leaving your editor. Powered by three.ws.

x402 is a protocol for developers and agents, not end users, so unlike a 3D viewer this is genuinely editor-native: the people wiring up paid endpoints and calling them live in VS Code.

Features

• Bazaar sidebar — live list of paid x402 HTTP APIs and MCP tools, merged across every facilitator via the three.ws discovery proxy (/api/bazaar/list, /api/bazaar/search). Filter by type, price, and tag; full-text search.
• Inspect an endpoint — paste any URL and decode its 402 challenge: every accepted network, asset, scheme, price (in USD), and payTo, with the rail each accept settles on ([solana] / [evm]) and the one this wallet can satisfy flagged.
• Pay & call — make a real paid request and settle it on the right rail automatically: USDC or $THREE on Solana via the real @x402/svm exact scheme, or USDC on Base and other EVM chains via @three-ws/x402-fetch. The exact USD amount, token, and network are shown and confirmed before signing; a spending cap blocks anything above your limit. The response body and on-chain settlement receipt (tx hash) render inline.
• Two secure wallets — an EVM key and a Solana key, each stored only in VS Code SecretStorage (the OS keychain). Never in settings, never on disk in plaintext. The status bar shows both derived addresses.
• Scaffold a paid endpoint — generate a working api/x402/<slug>.js that follows the repo's canonical paidEndpoint() pattern, wired end-to-end from the first deploy.

Setup

1. Install the extension and open the x402 Bazaar view in the activity bar.
2. Set a wallet key for the rail you want to pay on:
   • x402: Set Solana Wallet Key — a base58 secret key (or JSON byte array) for a funded Solana wallet holding USDC and/or $THREE.
   • x402: Set EVM Wallet Key — a 0x + 64 hex key for a funded Base USDC wallet. Either or both; keys are stored in your OS keychain.
3. Browse or search the bazaar, open a service, and Pay & call.

Settings

| Setting | Default | Purpose | |---|---|---| | threewsX402.origin | https://three.ws | Host of the bazaar discovery API. | | threewsX402.maxPaymentUsd | 0.10 | Per-request spending cap, in USD. | | threewsX402.confirmEachPayment | true | Confirm the exact amount before signing. | | threewsX402.network | "" (auto) | Preferred CAIP-2 network when a service accepts several (solana:… or eip155:…). Auto prefers USDC on Solana, then Base. | | threewsX402.preferToken | auto | Token to pay when several are offered: auto (USDC first, then $THREE), usdc, or three. | | threewsX402.filters | { "type": "http" } | Default bazaar filters. |

How payment works

The extension reads the 402 challenge and picks a payable requirement across both rails, honouring network and preferToken.

• Solana (solana:*): the real @x402/svm exact scheme signs an SPL transfer of the selected token (USDC or $THREE, mint FeMbDoX7R1Psc4GEcvJdsbNbZA3bfztcyDCatJVJpump) from your key and retries with the X-PAYMENT proof. This is the same buyer @three-ws/x402-mcp uses.
• EVM (eip155:*): @three-ws/x402-fetch signs a USDC EIP-3009 transferWithAuthorization on Base (or another EVM chain) and retries with the proof.

Either way the merchant settles on-chain and returns the work plus a settlement receipt, rendered inline with the token, network, and transaction hash. A service that only accepts a rail you have no key for is flagged, and the extension offers to set the matching wallet.

Development

npm install
npm run build        # bundle to dist/extension.cjs
npm run watch        # rebuild on change
npm test             # requirement selection, token rules, scaffold template

Press F5 in VS Code to launch an Extension Development Host.

All rights reserved (see LICENSE) · part of the three.ws monorepo.