Knowmint

KnowMint MCP Server

The first knowledge marketplace where AI agents pay directly with SOL — autonomously via x402.

Connect Claude Code, Cursor, or OpenCode to KnowMint. Agents autonomously discover, evaluate, and purchase battle-tested solutions, prompts, datasets, and domain know-how via the x402 protocol — paying sellers directly with SOL.

Human-in-the-loop mode also available: agent proposes a purchase, you approve in seconds. Your choice of autonomy level.

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Quickstart (npx — no install needed)

Claude Code (~/.claude/mcp.json)

{

"mcpServers": { "knowmint": { "command": "npx", "args": ["--yes", "--package", "@knowmint/mcp-server@0.1.2", "mcp-server"], "env": { "KM_API_KEY": "km_xxx", "KM_BASE_URL": "https://knowmint.shop" } } } }

Cursor (~/.cursor/mcp.json)

{

"mcpServers": { "knowmint": { "command": "npx", "args": ["--yes", "--package", "@knowmint/mcp-server@0.1.2", "mcp-server"], "env": { "KM_API_KEY": "km_xxx", "KM_BASE_URL": "https://knowmint.shop" } } } }

OpenCode (.opencode/config.json)

{

"mcp": { "servers": { "knowmint": { "command": "npx", "args": ["--yes", "--package", "@knowmint/mcp-server@0.1.2", "mcp-server"], "env": { "KM_API_KEY": "km_xxx", "KM_BASE_URL": "https://knowmint.shop" } } } } }

Claude Desktop (~/Library/Application Support/Claude/claude_desktop_config.json)

{

"mcpServers": { "knowmint": { "command": "npx", "args": ["--yes", "--package", "@knowmint/mcp-server@0.1.2", "mcp-server"], "env": { "KM_API_KEY": "km_xxx", "KM_BASE_URL": "https://knowmint.shop" } } } }

Windows: %APPDATA%\Claude\claude_desktop_config.json

`KM_BASE_URL` defaults to https://knowmint.shop when omitted.

Get your API key at knowmint.shop/settings/api or run km login.

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Available Tools

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Authentication

Priority order:

1. KM_API_KEY environment variable
2. ~/.km/config.json (saved by km login)

If you've already run km login, you can omit the env block entirely.

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Autonomous Purchase Flow (x402 — no external wallet MCP needed)

Agents with their own wallet (e.g. CDP Wallet) can complete purchases end-to-end without any additional MCP server:

1. km_get_content(id)

→ { payment_required: true, accepts: [{ payTo, maxAmountRequired, asset, network, ... }] }

1. Agent sends SOL/USDC from its own wallet → obtain tx_hash / signature

1. Build payment_proof: base64url(JSON.stringify({ scheme: "exact", network: " ", // match the network returned above payload: { txHash: " ", asset: "native" } }))

1. km_get_content(id, payment_proof: " ") → { full_content: "...", file_url: null }

Note: Use the network value returned in accepts[] — do not hardcode it.

Devnet example: "solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1"

Manual purchase via Phantom MCP also works: send tx → km_purchase(id, tx_hash) → km_get_content(id).

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Local Development Setup

cd mcp && npm install && npm run build

{

"mcpServers": { "knowmint": { "command": "node", "args": ["/path/to/knowledge_market/mcp/dist/index.js"], "env": { "KM_API_KEY": "km_xxx" } } } }

Dev mode (TypeScript, no build step)

{

"mcpServers": { "knowmint": { "command": "node", "args": ["--experimental-strip-types", "/path/to/knowledge_market/mcp/src/index.ts"], "env": { "KM_API_KEY": "km_xxx" } } } }

Verify the server starts

# Should print error to stderr and exit (no KM_API_KEY set)

npx --yes --package @knowmint/mcp-server@0.1.2 mcp-server

With key — should stay running (waiting for MCP messages on stdin)

KM_API_KEY=km_xxx KM_BASE_URL=http://localhost:3000 npm run dev

Interactive inspection

npx @modelcontextprotocol/inspector node --experimental-strip-types mcp/src/index.ts

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Requirements

• Node.js ≥ 22.6.0
• KnowMint API key (get one here)