ouija-mcp

MCP server exposing ouija's identity-collapse rails to any MCP-capable agent.

One BIP-39 mnemonic → one Ed25519 keypair → three identities:

• a Solana wallet (base58(pubkey))
• a Tor v3 .onion address (base32(pubkey || checksum || version))
• a deterministic storage namespace (the pubkey is a seed for PDAs)

This server lets agents do the derivation math, convert between encodings, query Solana balances on any cluster, and look up the deployed ouija-group program — without re-implementing any crypto.

Install

cd /Users/stacc/ouija-mcp
npm install
npm run build

Then register with Claude Code:

# from npm (recommended — auto-fetches latest)
claude mcp add ouija -s user -- npx -y ouija-mcp

# or from a local clone
claude mcp add ouija -s user -- node /Users/stacc/ouija-mcp/dist/index.js

Or wire into any MCP client by pointing it at npx -y ouija-mcp (stdio transport).

Tools

| Tool | What it does | |---|---| | derive_identity({mnemonic, passphrase?}) | Full identity: Ed25519 seed + pubkey + Solana address + .onion. Path m/44'/501'/0'/0' (matches Phantom/Solflare/Backpack). | | onion_to_solana({onion}) | Tor v3 .onion → Solana wallet address | | solana_to_onion({solana_address}) | Solana → .onion (math only — service may or may not be live) | | ouija_get_sol_balance({address, cluster?}) | Lamports + SOL on mainnet / devnet / testnet / custom RPC URL | | ouija_get_token_balances({address, cluster?}) | All SPL + Token-2022 holdings with non-zero balance | | ouija_compute_pda({seeds, program_id}) | Generic PDA derivation. Seeds support utf8:, hex:, base58: prefixes. | | ouija_group_program_info() | Deployed program ID + PDA layout + instruction list for the ouija-group Anchor program. |

Verification vector

Standard BIP-39 test mnemonic abandon × 11 + about at m/44'/501'/0'/0' MUST produce:

• Solana: HAgk14JpMQLgt6rVgv7cBQFJWFto5Dqxi472uT3DKpqk
• .onion: 6a3coysgu5nz3yzut3kcwfpcgl3fdd6cb5p42ty5mtub7g6sld35qlid.onion

Verified across:

• Go bridge (ouija-bridge, SeedFromMnemonic + tor.GetTorV3Hostname)
• This MCP server (@noble/curves + manual SLIP-0010 + base32 encoding)
• Phantom wallet (import the mnemonic, derived address matches)

Any other implementation that produces a different result has a bug.

Why this exists

Agents working in the Solana × Tor space repeatedly need the same primitives:

• "what Solana wallet does this .onion correspond to"
• "derive everything from a mnemonic"
• "what's the balance on devnet"
• "compute the PDA for these seeds"

Re-implementing in each agent / project is wasteful and error-prone (especially the base32 + checksum + version byte ordering for v3 onions, which is easy to get wrong). This server is the single source of truth.

Related work

• ouija (Go) — Cwtch fork with the same identity primitive baked in: /Users/stacc/ouija
• ouija-bridge (Go FFI) — exposes the same derivation to Flutter via c_ exports: /Users/stacc/ouija-bridge
• ouija-ui (Flutter) — Cwtch UI with the wallet panel: /Users/stacc/ouija-ui
• ouija-group (Anchor) — hybrid group state program (Solana + optional Tor relay): /Users/stacc/ouija-group. Deployed on mainnet at EsrqfUpGRmYppZJ6spQtQJ2QzdSCQHYhvYXXHgpBRqhG (default) and on devnet at BcwsnKq3DLoTsp1AuP3Nuu4Z1WJuLa162DCZVok7aRKv (free testing — solana airdrop 1 <addr> --url devnet).
• SKILL.md — agent-facing skill explaining when + how to use these rails: /Users/stacc/.claude/skills/ouija/SKILL.md

License

Same as parent project (Cwtch is MIT; ouija additions inherit).