Everything up to payment is free — searching, reading previews, comparing prices — and the paywall only appears when full content is requested, so an agent can evaluate before it commits. Decide the autonomy level deliberately: with a funded keypair configured, the buy step needs no human, and the same setup supports the human-in-the-loop pattern where the agent proposes and you approve. Publishing runs on the same account, so an agent that has produced something worth selling can list it without a separate flow.
A paid knowledge marketplace with the payment step inside the tool loop. Items are searched and previewed for free; retrieving the full content returns a payment-required response, and the purchase is settled by an on-chain Solana transfer straight from buyer to seller.
- Search across listed knowledge items returning title, description, price and metadata, filterable by content type, domain, source type and experience type
- An item's detail and preview content, which is the material for deciding whether it is worth buying before any money moves
- Full content retrieval that answers payment_required when the item is unpaid, and returns the content when a base64 payment proof accompanies the retry
- A purchase recorded against a transaction hash after payment has been sent on-chain, which is what unlocks access
- Version history for an item, so a piece of knowledge that has been revised shows its past snapshots
- Publishing in one step: title, description, content type, content and tags, priced in SOL or USDC
- Account setup from a Solana keypair — registration that handles the challenge, signature and API key in one call, and a re-login for when a key needs replacing
A Solana keypair file on disk, and an API key in KM_API_KEY — though you do not need one before you start, because the registration tool creates the account from the keypair and saves the key to a config file in your home directory for later calls. Node.js 22.6.0 or newer; it runs over stdio as npx --package @knowmint/mcp-server mcp-server. KM_BASE_URL points at the instance and defaults to the hosted marketplace. Buying means spending real funds from that keypair: transfers go directly from buyer to seller on Solana with no platform custody, so the wallet you point at it is the wallet that pays. MIT.
One command — npx -y @knowmint/mcp-server