Penny Press

npx add-mcp 'https://www.pennypress.org/mcp'

Penny Press — MCP Server

Free for humans. Pennies for machines.

Penny Press (pennypress.org) is a pseudonymous pay-per-read writing vault: essays on freedom, economics and philosophy. People read the full text free in a browser — no accounts, no signup. Programmatic access costs a few cents in USDC on Base per read, gated by the x402 payment protocol.

Connect

Remote MCP server over streamable HTTP — no installs, no Docker, no config files. Paste the endpoint into your AI client:

• Endpoint: https://www.pennypress.org/mcp

Client	Where to add
Claude Desktop	claude_desktop_config.json → url field
Cursor	Settings → MCP → Add Server URL
Windsurf	MCP Config → Remote

Tools (all free)

• list_essays (no arguments) — catalog: titles, descriptions, prices, and reading URLs for every published piece.
• essay_payment_info (slug required, e.g. river-of-time) — the x402 payment details for one piece: price, network, asset, and recipient wallet.
• lexicon_lookup (term required, e.g. fiat-order) — free metadata for a Lexicon term: part of speech, essays where it appears, plus payment info for the $0.01 full definition.
• lexicon_snapshot_info (no arguments) — payment details for the $0.25 full Lexicon dataset snapshot.
• common_cents_info (no arguments) — the Common Cents collection: five themes, quote count, and payment info for the $0.01 full set.
• witness_verify (content_hash required) — check whether a SHA-256 fingerprint has been witnessed by LitWit. Free.
• witness_attest_info (no arguments) — how LitWit attestation works and the $0.05 payment details.

The Literary Witness module behind witness_* is open source (MIT) under litwit/ — hash-chained, DNS-anchored timestamping for writers.

LitWit is listed on PayAPI Market with a settlement-verified badge — PayAPI paid a real $0.05 attestation call and received a real receipt.

Reading (paid for machines)

GET https://www.pennypress.org/essays/{slug} returns the full text, machine edition:

1. Request it without payment. You get 402 Payment Required with payment instructions (x402 v2, scheme exact, USDC on Base).
2. Sign the payment with your own wallet tooling and retry with the payment proof in the Payment-Signature header.

Exact per-piece prices: GET https://www.pennypress.org/.well-known/x402 — the source of truth for prices and network. Payment requires a Base wallet holding USDC. No account or signup anywhere in this flow.

Machine-readable docs: /llms.txt, /skill.md, /essays (free catalog). See SKILL.md for the full agent skill, including security rules.

Security

Your wallet stays on your side. Nothing here asks for private keys, seed phrases, or wallet exports. Sign payments only with your own trusted wallet tooling, and verify the recipient matches the 402 instructions before signing.

License

Documentation in this repository is licensed under CC-BY-4.0. Code (the litwit/ module) is licensed under MIT. The essays themselves remain the work of their pseudonymous author.

Claude Code plugin

Install the Penny Press skills pack in Claude Code:

/plugin marketplace add con-scribe/penny-press-mcp
/plugin install penny-press@penny-press

Four skills (penny-press-read, penny-press-lexicon, penny-press-common-cents, penny-press-litwit) plus the Penny Press MCP server (https://www.pennypress.org/mcp). Free for humans. Pennies for machines. See plugins/penny-press/README.md.