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.

Pay with $THREE on Solana

Set threewsX402.preferToken to three to prefer endpoints that accept the three.ws ecosystem token.

• Symbol: $THREE
• Network: Solana
• Contract address: FeMbDoX7R1Psc4GEcvJdsbNbZA3bfztcyDCatJVJpump
• Payment scheme: x402 exact through @x402/svm

The extension only selects $THREE when the endpoint advertises that exact mint in its 402 challenge. It shows the amount, network, paying address, and recipient, then requires explicit confirmation before signing. Read the full x402 for VS Code guide.

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.

The USD spending cap applies to USDC payments. A non-stable token such as $THREE is always shown in token units and always requires explicit confirmation because the 402 challenge does not provide a fiat conversion.

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.

Apache-2.0 (see LICENSE) · part of the three.ws monorepo.

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Built for AI agents too

Coding agents and LLM tooling can read this repo directly: AGENTS.md, llms.txt, llms-full.txt. Point an agent at https://github.com/nirholas/vscode-x402 and it has the context it needs.

More from the same author

• All repositories by nirholas: the full catalog, grouped by topic
• three.ws: the platform for 3D AI agents with Solana wallets, a skill marketplace and x402 payments
• Questions or ideas: open an issue or start a discussion

Contributors

Star history

Part of three.ws

three.ws is a platform for 3D AI agents with Solana wallets: avatars, a skill marketplace, x402 payments and more than seventy MCP servers. @three-ws/vscode-x402 is one package from it.

• Documentation site: https://nirholas.github.io/vscode-x402/
• npm: https://www.npmjs.com/package/@three-ws/vscode-x402
• Canonical source: https://github.com/nirholas/three.ws (this repository is a generated mirror of packages/vscode-x402)
• Agent-readable summary: llms.txt and AGENTS.md
• Issues and ideas: https://github.com/nirholas/vscode-x402/issues