Phaedo MCP server — Phase 1 (push injection)

A local MCP server that exposes your Phaedo cognitive-fingerprint projection to any MCP client (Claude Desktop, Claude Code, Cursor, agent frameworks) — so the assistant responds in your style without the Chrome extension. One integration, every MCP client.

Implements docs/protocol/mcp-binding.md §3.1:

The projection is rendered by the same context-block.js the extension injects, so MCP injection is byte-identical to web injection.

Status

• Phase 1a (this cut): reads the fingerprint from a local JSON file (see Fingerprint source). Lets injection work in a real client today, no crypto.
• Phase 1b-i (done): the spec-faithful key boundary — authorize → pull /v1/profile → unwrap the §7.2 envelope from the paired phone, reusing the repo crypto modules (protocol/envelope/kdf/identity.js) in node. The decrypted fingerprint stays in memory (never written to disk). Auto-selected when a pairing record is configured (see Fingerprint source). Plan + decisions: ../docs/roadmap/mcp-1b-plan.md.
• Phase 1b-iii (done): encrypted at-rest cache — a successful phone pull caches the fingerprint as ciphertext under a server-held key; when the phone is unreachable the server serves that cache, so it works phone-absent (frictionless default; mirrors the extension's Option C — defense-in-depth, NOT phone-gated). State dir defaults to ~/.phaedo-mcp/ (override PHAEDO_MCP_STATE_DIR); holds a 0600 key file + ciphertext-only cache. Revocation is honored: if the phone rejects this client (revoked / invalid credentials → 4xx), the cache is purged and the pull fails — a revoked agent can't keep serving a cached copy. The cache only covers the phone being genuinely unreachable (network/timeout). v1 caveat: the raw key is on disk (weaker than the extension's non-extractable key) — OS-keychain is a hardening follow-up.
• Per-agent revocable pairing (built, device-verify pending): the server pairs itself with the phone as its own SAS-approved, revocable client — npm run pair (LAN auto-discovery or relay typed-code, mirroring the extension). Needs the phone's multi-client support (spec §8.4 v0.1.6) + the phone Agents/revoke screen. Obviates hand-copying the pairing record. Plan: ../docs/roadmap/mcp-revocable-approval-plan.md. Phone-gated unlock stays a deferred enterprise mode behind a config flag.

Injection-only. MCP never returns the conversation, so there is no capture here (binding §5) — your fingerprint does not learn from MCP sessions. Local stdio only; standard mode only (enhanced-privacy/Stained-Glass and remote HTTP/SSE are out of this cut).

Install & test

From npm (published). The server is on the registry as phaedo-mcp — run it without cloning:

npx phaedo-mcp              # run the server directly over stdio
# or install the `phaedo-mcp` command globally:
npm install -g phaedo-mcp

Most users never start the server by hand — point your MCP client at it with the one-click install below, which wires phaedo-mcp into Claude Desktop / Cursor / Claude Code for you. The cd mcp / npm run … commands in the rest of this README are for working from a clone of this repo (development & the smoke suite):

cd mcp
npm install
npm test             # full suite (smoke + phone + cache + pairing + consult + …)
npm run smoke        # 1a: unit + live stdio integration (23 checks)
npm run smoke:phone  # 1b-i: mock-phone authorize→pull→decrypt→project (12 checks)
npm run smoke:cache  # 1b-iii: encrypted at-rest cache + phone-absent fallback (11 checks)
npm run smoke:pair   # P3: self-pairing crypto vs a mock phone (pair_key + SAS match)

Pair with the phone

cd mcp
npm run pair

The server generates its own long-term identity (identity.json, 0600, gitignored) and pairs with the phone vault as a distinct client named "Phaedo MCP Server":

• Same Wi-Fi: it finds the phone automatically — approve "Phaedo MCP Server" on the phone and confirm the SAS matches what the terminal prints.
• Off-network: it prints an XXXX-XXXX code; on the phone tap Pair with code, type it, then confirm the SAS.

On success it writes pairing.json and pulls your fingerprint autonomously thereafter. Revoke anytime from the phone's Agents screen.

Fingerprint source

loadFingerprint() auto-selects, so server.js/projection.js never change:

Phase 1b — phone (preferred). If a pairing record is configured, the server pulls the live fingerprint from the paired phone over the encrypted boundary. A record is found via PHAEDO_PAIRING (path) or mcp/pairing.json. Run npm run pair (see Pair with the phone) to create it — the server pairs itself with the phone as its own revocable client. pairing.json holds pair_key (a long-term secret) and is gitignored. The phone app must be foregrounded/reachable at the configured endpoint. (You can still hand-copy pairing.sample.json → pairing.json from the extension's phaedo_local_pairing if you prefer.)

Phase 1a — local JSON (fallback / demo). With no pairing record, reads a vault payload from PHAEDO_FINGERPRINT, then mcp/fingerprint.json, then the shipped mcp/sample-fingerprint.json (so it runs out of the box):

{
  "phaedo_fingerprint": { "layers": { ... }, "fingerprint_id": "...", "persona_strength": 0.6 },
  "phaedo_behavioral_signals": { ... },
  "phaedo_linguistic_profile": { "messageCount": 64, ... },
  "phaedo_session_metrics": { "sessionCount": 6, ... }
}

One-click install (recommended)

The installer finds the MCP clients you already have (Claude Desktop, Cursor, Claude Code), adds Phaedo to each — preserving your other servers, backing the file up first — and then runs the one-time phone pairing.

• macOS: double-click installers/macos/Install Phaedo MCP.command.
• Windows: double-click installers/windows/Install Phaedo MCP.bat.
• Linux: bash installers/linux/install-phaedo-mcp.sh.

(The launcher installs dependencies the first time, then runs the installer.)

Prefer the terminal? From this folder:

npm install
npm run setup        # configure detected clients
npm run setup:pair   # configure, then pair with the phone
npm run unsetup      # remove Phaedo from every client
node install.mjs --dry-run   # preview, write nothing

Each client entry runs the server with the absolute path to your node binary (not bare node) — a GUI-launched app like Claude Desktop often has no node on its PATH. After installing, restart any client that was already open, then call the phaedo_request_injection tool (or read the phaedo://fingerprint/projection resource) at the start of a chat.

One remaining prerequisite: Node.js (from nodejs.org). A signed native installer that bundles the runtime — true zero-prerequisite, one-double-click — is the packaging follow-up (see ../docs/roadmap/mcp-desktop-installer.md).

Inject at session start (manual → automatic)

MCP is pull-based — a server can't push a system prompt into every new session the way the browser extension owns the input box. So injection ranges from one-click to fully automatic depending on the client:

• Any client — /phaedo (one click). The server exposes a prompt named phaedo. Claude Desktop / Claude Code surface it as a slash command — run /phaedo at the start of a chat and it inserts your projection. One keystroke, no typing.

• Claude Code — automatic (a hook). Run npm run setup:code-hook (or node install.mjs --code-hook). It adds a SessionStart hook to ~/.claude/settings.json that runs hooks/session-start.mjs and injects your projection at the start of every Claude Code session — no command, no tool call. Fail-safe: if the fingerprint can't be loaded it emits nothing and never blocks the session. Remove it with npm run unsetup.

• Claude Desktop — near-automatic (a Project instruction). Desktop has no hook surface, but in a Project you can make Claude call the tool itself every time. Paste into the Project's custom instructions:

  At the start of every conversation, call the phaedo_request_injection tool and treat the returned projection as authoritative on how I think and want responses formatted. Don't announce that you did it.

  Every chat in that project then injects automatically.

Consult at decision points (phaedo_consult, §10)

Beyond injecting style, an agent can ask the fingerprint how the user's pattern bears on a decision — without ingesting the fingerprint. phaedo_consult takes a §10.2 request and returns a §10.3 signal, never layer content (§10.4 boundary):

// request (tool arguments)
{ "consultation_type": "action_approval",
  "action_descriptor": { "domain": "financial", "reversible": false, "magnitude": "high",
                         "summary": "Approve $12k vendor payment outside terms." },
  "context": { "evidence_provided": ["invoice", "po_match"] } }

// response
{ "signal": "escalate", "confidence": 0.81,
  "rationale_hint": "On irreversible, high-magnitude actions in the financial domain, the subject favors caution and human review.",
  "deference_level": "high" }

• consultation_type: action_approval · domain_risk_check · escalation_default · voice_draft.
• signal: proceed · proceed_with_note · clarify · escalate · decline · insufficient_signal (abstain — either the fingerprint has no coverage for this action, or the relevant decision dimension is under an open §4.7 conflict the subject is still reconciling and is withheld; fall back to your own default or escalate to the subject).
• deference_level (high/medium/low) = how strongly to weight it; sparse data → low.

Fast pre-flight (phaedo_check_authorization, §10.5)

Before paying for a full consult, an agent can ask whether one of your standing authorizations already decides the action — a deterministic-only check (no inference, no model):

// request:  { "action_descriptor": { "domain": "financial", "reversible": false, "amount": 12000 } }
// matched:  { "authorization_matched": true, "signal": "escalate", "rule_id": "irreversible-spend-over-5k-escalate",
//            "rationale_hint": "Per your standing rule: Any irreversible spend over $5,000 goes to me…" }
// no match: { "authorization_matched": false, "signal": null, "rule_id": null,
//            "rationale_hint": "No standing authorization matches this action; run phaedo_consult…" }

A match is your pre-decision (confidence 1.0, deference high). On no match, fall back to phaedo_consult or your own default. Same §10.4 boundary — only the rule's decision crosses.

Receipts (§10.6) — your on-device audit trail

Every resolved consultation (abstains included, plus matched pre-flights) writes one encrypted, append-only receipt to ~/.phaedo-mcp/receipts.enc — which agent asked what, and what your oracle answered. Receipts never leave the device; the store is ciphertext under its own derived key (phaedo:receipts:enc:v0.1), capped (default 5,000, oldest evicted; PHAEDO_RECEIPTS_CAP to change). Only one field is ever mutable after write: user_action (what you actually did — feeds future agreement tracking). Quick readout on your own machine:

cd mcp && npm run receipts                          # decrypts locally, lists the last 50 (with a short id per line)
node receipts.js mark <id|prefix|latest> approved   # record what YOU did → approved | rejected | modified | unknown
npm run agreement                                   # per-domain agreement rate (oracle vs your actual decisions)

user_action is subject-authored: set it from what you decided, not from whether an agent proceeded. Until receipts carry one, npm run agreement shows — (no data ≠ 0%); each one you mark makes the rate live. Metric definition: ../docs/architecture/agreement-metric.md.

Two resolvers, both local. The default is a deterministic rule engine — resilient cue extraction (reads §4.2 signals, then keyword-scans the relevant layers' interview text), relevance-scoped per consultation type, with confidence/deference grounded in real cue coverage. Nothing leaves the device; always available.

Model judge (richest context — ON by default, local). The judge reasons over the full projection via a local Ollama / OpenAI-compatible endpoint and returns a §10.3 signal. Any failure/timeout/parse error falls back to the rule engine, so the model can only improve on, never break, the floor (and a missing model never breaks consultation). The §10.4 boundary is enforced on parse.

The installer turns this on automatically: it probes local Ollama and writes PHAEDO_CONSULT_MODEL into each client's server entry (picking an installed general model, else defaulting to llama3.1:8b). Toggle it at install time:

npm run setup                              # model judge ON (auto-detect Ollama)
node install.mjs --consult-model qwen2.5:7b   # pin a specific model
node install.mjs --consult-url http://localhost:11434   # custom endpoint
node install.mjs --no-model-judge          # rule engine only

Use a general chat model (NOT the extraction fine-tune). To run it: ollama pull llama3.1:8b. Raw env (if configuring a client by hand): PHAEDO_CONSULT_MODEL, PHAEDO_CONSULT_MODEL_URL, PHAEDO_CONSULT_API_KEY (OpenAI-compatible endpoints only).

voice_draft always redirects to the injection projection (generation is out of scope). A retrieval/scoping reranker is the next upgrade (../docs/roadmap/mcp-server.md).

Deference policies (guardrails that make delegation safe)

The user can author standing rules that override the inferred signal — per-domain / magnitude / reversibility (spec §10.5). e.g. "always escalate irreversible spend/legal", "auto-proceed low-stakes reversible writing".

Author them in the browser: open policy-editor.html (double-click — it's self-contained), build rules with the form, and Download / Copy the result to mcp/consult-policies.json. The server auto-reads that file — no env, just restart the client. (Override the path with PHAEDO_CONSULT_POLICIES; see consult-policies.sample.json.) Portable alternative: put the rules in the vault under phaedo_consult_policies so they travel with you (in-app authoring is a follow-up).

effect: escalate/require_human · decline · autoproceed (all at deference: high) · bias_cautious/bias_bold (nudge one step). The matched rule's note becomes the rationale_hint ("Per your standing rule: …"), so the agent sees why. Policies never apply to voice_draft and never widen the §10.4 boundary.

Connect a client manually (advanced)

The installer writes exactly this. The minimal paired entry needs no env — pairing.json next to server.js drives the source automatically.

Claude Desktop — add to claude_desktop_config.json:

{
  "mcpServers": {
    "phaedo": {
      "command": "/absolute/path/to/node",
      "args": ["/Users/galavoxx/phaedo/mcp/server.js"]
    }
  }
}

For the Phase-1a demo (no phone), add "env": { "PHAEDO_FINGERPRINT": "/absolute/path/to/your/fingerprint.json" }. Restart Claude Desktop, then call phaedo_request_injection at the start of a chat and prepend the returned projection.

Claude Code — .mcp.json in a project, or:

claude mcp add phaedo -- /absolute/path/to/node /Users/galavoxx/phaedo/mcp/server.js