vestige/crates/vestige-mcp
NoahToKnow 9c022a0f54 fix(deep_reference): incorporate query relevance into recommended/confidence
The Stage 8 `recommended` selector and the evidence sort both rank by
FSRS-6 trust only, discarding the `combined_score` signal that the
upstream hybrid_search + cross-encoder reranker just computed. Confidence
is then derived from `recommended.trust + evidence_count`, neither of
which moves with the query — so any query against the same corpus
returns the same primary memory and the same confidence score.

Empirical reproduction (15 deep_reference probes against an 11-memory
corpus, 9 with a unique correct answer + 6 with no relevant memories):

  - Distinct primary memories returned : 1 / 15
  - Confidence values returned         : 1 distinct (0.82 for all)
  - Ground-truth accuracy on specific queries : 1 / 9 (11.1%)

The single hit is coincidental: the always-returned memory happened to
be the correct answer for one query. Random guessing across the 11-memory
corpus would be ~9% baseline, so the tool is performing at random.

Fix
---

Replace trust-only ranking at three sites with a 50/50 composite of
combined_score (query relevance) and FSRS-6 trust:

    let composite = |s: &ScoredMemory| s.combined_score as f64 * 0.5 + s.trust * 0.5;

Used in:
  - cross_reference.rs:573 — `recommended` max_by
  - cross_reference.rs:589 — `non_superseded` evidence sort_by
  - cross_reference.rs:622 — `base_confidence` formula

The 50/50 weighting is a design choice — see PR body for the knob to
tweak if a different blend is preferred. The pre-existing updated_at
tiebreaker is preserved.

Tests
-----

Two regression tests, both verified to FAIL on `main` and PASS with the
fix via negative control (temporarily set the composite weights to
1.0 trust + 0.0 relevance and confirmed both tests fail again):

  - test_recommended_uses_query_relevance_not_just_trust
      Two-memory corpus, ingested in order so the off-topic memory wins
      the trust tiebreaker. Query targets the on-topic memory. The fix
      ensures `recommended` is the on-topic one.

  - test_confidence_varies_with_query_relevance
      Single-memory corpus. Identical execute() calls with a relevant
      query and an irrelevant query. The fix ensures the relevant
      query produces higher confidence.

Full crate suite: 410 / 410 passing (was 408 + 2 new).

Out of scope
------------

While running the live MCP probes I observed two further inconsistencies
in `cross_reference.rs` that I cannot reproduce in cargo test (the
synthetic test environment with mock embeddings does not trigger the
required combined_score > 0.2 floor condition):

  - The `effective_sim` floor at line 551 fabricates contradictions
    between memories with no real topical overlap when one contains a
    CORRECTION_SIGNALS keyword.
  - The Stage 5 `contradictions` field (strict) and the Stage 7
    `pair_relations` feeding the reasoning text (loose, post-floor)
    disagree, producing responses where `reasoning` claims N
    contradictions while `contradictions` is empty and `status` is
    "resolved".

I have empirical data for both from live MCP usage but no reproducible
cargo test, so they are intentionally not addressed in this PR. Happy to
file them as a separate issue with the raw probe data if useful.
2026-04-09 20:09:56 -06:00
..
src fix(deep_reference): incorporate query relevance into recommended/confidence 2026-04-09 20:09:56 -06:00
Cargo.toml feat: v2.0.4 "Deep Reference" — cognitive reasoning engine + 10 bug fixes 2026-04-09 16:15:26 -05:00
README.md Switch embedding model from BGE to nomic-embed-text-v1.5 2026-01-25 03:11:15 -06:00

Vestige MCP Server

A bleeding-edge Rust MCP (Model Context Protocol) server for Vestige - providing Claude and other AI assistants with long-term memory capabilities.

Features

  • FSRS-6 Algorithm: State-of-the-art spaced repetition (21 parameters, personalized decay)
  • Dual-Strength Memory Model: Based on Bjork & Bjork 1992 cognitive science research
  • Local Semantic Embeddings: nomic-embed-text-v1.5 (768d) via fastembed v5 (no external API)
  • HNSW Vector Search: USearch-based, 20x faster than FAISS
  • Hybrid Search: BM25 + semantic with RRF fusion
  • Codebase Memory: Remember patterns, decisions, and context

Installation

cd /path/to/vestige/crates/vestige-mcp
cargo build --release

Binary will be at target/release/vestige-mcp

Claude Desktop Configuration

Add to your Claude Desktop config (~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

{
  "mcpServers": {
    "vestige": {
      "command": "/path/to/vestige-mcp"
    }
  }
}

Available Tools

Core Memory

Tool Description
ingest Add new knowledge to memory
recall Search and retrieve memories
semantic_search Find conceptually similar content
hybrid_search Combined keyword + semantic search
get_knowledge Retrieve a specific memory by ID
delete_knowledge Delete a memory
mark_reviewed Review with FSRS rating (1-4)

Statistics & Maintenance

Tool Description
get_stats Memory system statistics
health_check System health status
run_consolidation Apply decay, generate embeddings

Codebase Tools

Tool Description
remember_pattern Remember code patterns
remember_decision Remember architectural decisions
get_codebase_context Get patterns and decisions

Available Resources

Memory Resources

URI Description
memory://stats Current statistics
memory://recent?n=10 Recent memories
memory://decaying Low retention memories
memory://due Memories due for review

Codebase Resources

URI Description
codebase://structure Known codebases
codebase://patterns Remembered patterns
codebase://decisions Architectural decisions

Example Usage (with Claude)

User: Remember that we decided to use FSRS-6 instead of SM-2 because it's 20-30% more efficient.

Claude: [calls remember_decision]
I've recorded that architectural decision.

User: What decisions have we made about algorithms?

Claude: [calls get_codebase_context]
I found 1 decision:
- We decided to use FSRS-6 instead of SM-2 because it's 20-30% more efficient.

Data Storage

  • Database: ~/Library/Application Support/com.vestige.mcp/vestige-mcp.db (macOS)
  • Uses SQLite with FTS5 for full-text search
  • Vector embeddings stored in separate table

Protocol

  • JSON-RPC 2.0 over stdio
  • MCP Protocol Version: 2024-11-05
  • Logging to stderr (stdout reserved for JSON-RPC)

License

MIT