BetterDB Memory for Claude Code

Persistent, semantic memory for Claude Code sessions — powered by Valkey.

Every time you start a new Claude Code session, context is lost. BetterDB Memory automatically captures what you did, embeds it as vectors in Valkey, and retrieves relevant history at the start of each new session.

Quick Start

Prerequisites

• Bun runtime — required (the CLI and all hooks run on Bun, not Node)
• Claude Code installed
• Valkey 8.0+ with the Search module

Install

# 1. Copy .env.example and fill in your settings
cp .env.example .env

# 2. Install
bunx @betterdb/memory install

The install will:

1. Compile native hook binaries to ~/.betterdb/bin/
2. Register 4 lifecycle hooks with Claude Code
3. Register the MCP server for mid-conversation tools
4. Create the Valkey search index
5. Save your .env values to ~/.betterdb/memory.json for runtime use

Don't have Valkey?

The setup skill will offer to spin one up in Docker for you. Or run it manually:

# Via CLI
bunx @betterdb/memory docker-valkey

# Or directly with Docker
docker run -d --name betterdb-valkey -p 6379:6379 -v betterdb-valkey-data:/data valkey/valkey-search:8 valkey-server --save 60 1

How It Works

Hook	What it does
SessionStart	Retrieves relevant memories via vector search, injects as context
PostToolUse	Records every tool call to a temp JSONL file
Stop	Summarizes the session, embeds it, stores in Valkey
PreToolUse	Surfaces file-specific history when accessing known files

MCP Tools

Claude can use these mid-conversation:

• search_context — Semantic search over past sessions. Escalates project+branch → project → cross-project, and takes an optional tags filter (decision, pattern, problem, open-thread)
• store_insight — Save a decision, pattern, or warning
• list_open_threads — Show unresolved items
• forget — Delete a specific memory

CLI Commands

bunx @betterdb/memory install        # Set up hooks + MCP server
bunx @betterdb/memory status         # Check health + recall scoring config
bunx @betterdb/memory uninstall      # Remove everything
bunx @betterdb/memory maintain       # Run aging/compression manually
bunx @betterdb/memory forget         # Bulk-delete by scope (dry run; --apply to delete)
                                     #   --project <name> | --all-projects --branch <b> --tags <a,b>
bunx @betterdb/memory docker-valkey  # Manage Docker Valkey container

Configuration

Copy .env.example to .env and fill in your values before running bunx @betterdb/memory install. They get saved to ~/.betterdb/memory.json and used by the compiled binaries at runtime.

Core

Variable	Default	Description
BETTERDB_VALKEY_URL	redis://localhost:6379	Valkey connection URL
BETTERDB_VALKEY_INDEX_NAME	betterdb-memory-index	Valkey search index name
BETTERDB_EMBED_DIM	1024	Embedding dimensions
BETTERDB_MAX_CONTEXT_MEMORIES	5	Max memories injected per session (after gating)
BETTERDB_CONTEXT_FILE	.betterdb_context.md	Context injection file
BETTERDB_ALLOW_REMOTE_FALLBACK	true	Fall back to remote APIs if local models unavailable

Recall Gating

Recall over-fetches a candidate pool, gates it by relevance, and escalates on a miss (project+branch → project → cross-project). Memories are stored with their git branch as a native thread scope and content-type tags, so recall can narrow to the current branch first and filter by type. search_context returns nothing only when nothing clears the bar — so a miss is honest, not a silent drop.

The gate is relative, not an absolute similarity threshold: embed models compress cosine similarity into different, narrow bands (mxbai-embed-large packs everything into ~0.7–0.88), so a fixed threshold doesn't transfer across models. Instead, floor drops genuine noise, and hits within margin of the top match are kept; confidence comes from the scale-independent top-vs-next gap.

Variable	Default	Description
BETTERDB_RECALL_FLOOR	0.5	Similarity floor — drops noise and loosens the store's own distance gate
BETTERDB_RECALL_MARGIN	0.05	Keep hits within this similarity of the top match
BETTERDB_RECALL_SEPARATION	0.04	Top-vs-next gap above which a match is "high" confidence
BETTERDB_RECALL_POOL_K	10	Rung-1 over-fetch pool (project)
BETTERDB_RECALL_POOL_K_WIDE	20	Rung-2/3 over-fetch pool (wider / cross-project)
BETTERDB_ALLOW_CROSS_PROJECT	true	Allow escalation / scope="all" to search across projects

Ranking within the gated pool uses a composite score (similarity + recency + importance), owned by @betterdb/agent-memory. Recency is the system's single time-decay — a half-life applied at query time, not a stored per-memory aging pass. These knobs tune it; defaults match the store's.

Variable	Default	Description
BETTERDB_RECALL_HALF_LIFE_DAYS	7	Age at which a memory's recency term halves
BETTERDB_RECALL_WEIGHT_SIMILARITY	0.6	Weight of semantic similarity in the composite score
BETTERDB_RECALL_WEIGHT_RECENCY	0.25	Weight of recency
BETTERDB_RECALL_WEIGHT_IMPORTANCE	0.15	Weight of stored importance

Model Providers

Variable	Default	Description
BETTERDB_EMBED_PROVIDER	auto-detect	Force embed provider: local, ollama, voyage, openai, groq, together
BETTERDB_SUMMARIZE_PROVIDER	auto-detect	Force summarize provider: ollama, anthropic, openai, groq, together
BETTERDB_EMBED_MODEL	mxbai-embed-large	Ollama embedding model name
BETTERDB_SUMMARIZE_MODEL	mistral:7b	Ollama summarization model name
BETTERDB_OLLAMA_URL	http://localhost:11434	Ollama API URL

Embeddings work with zero config

If no embedding provider is detected (no Ollama models, no API keys), BetterDB falls back to on-device embeddings via @xenova/transformers (all-MiniLM-L6-v2, 384-dim, Apache-2.0). No API key, no running service — the model weights download once on first use and are cached thereafter. Auto-detected providers (Ollama, then API keys) take priority when available.

API Keys

Embeddings always work (on-device fallback above). A summarization provider is still required — Ollama is free and local; the others require API keys.

Variable	Provider	Used for
ANTHROPIC_API_KEY	Anthropic	Summarization only (no embeddings)
VOYAGE_API_KEY	Voyage AI	Embeddings only
OPENAI_API_KEY	OpenAI	Embeddings + summarization
GROQ_API_KEY	Groq	Embeddings + summarization
TOGETHER_API_KEY	Together AI	Embeddings + summarization

Aging Pipeline

Variable	Default	Description
BETTERDB_COMPRESS_THRESHOLD	0.3	Importance threshold for compression
BETTERDB_DISTILL_MIN_SESSIONS	5	Min sessions before knowledge distillation
BETTERDB_AGING_INTERVAL_HOURS	6	Hours between automatic aging runs

License

MIT