The local-first cognitive memory kernel for AI agents
Memory physics, not just storage. Most agent memory systems store context. Engram evolves context — topology-driven decay, consolidation, and contradiction handling, all running locally with zero external API.
- Context Control — graph-Laplacian diffusion decays trivial chats so your context window doesn't choke on noise. Important, well-connected knowledge stays sharp; transient chatter fades.
- Contradiction Management — auto-detects when goals or architecture change, then archives the stale logic so the agent stops acting on decisions you already reversed.
- 100% Privacy-First — local ONNX embeddings + local SQLite. Your memory never leaves your machine. Zero external API, zero cloud, zero telemetry.
→ See the cold-start scorecard · Get started in 5 minutes
Quickstart
# Windows — clones, builds, and wires up your AI assistant automatically
irm https://raw.githubusercontent.com/wyckit/mcp-engram-memory/main/setup.ps1 | iex
# macOS / Linux
curl -fsSL https://raw.githubusercontent.com/wyckit/mcp-engram-memory/main/setup.sh | bash
First run downloads a ~5.7 MB embedding model (bge-micro-v2) — subsequent starts are instant.
Manual clone
git clone https://github.com/wyckit/mcp-engram-memory.git
cd mcp-engram-memory && dotnet restore
Add to your MCP client config:
{
"mcpServers": {
"engram-memory": {
"command": "dotnet",
"args": ["run", "--project", "/path/to/mcp-engram-memory/src/McpEngramMemory"],
"env": { "MEMORY_TOOL_PROFILE": "minimal" }
}
}
}
Docker
docker build -t mcp-engram-memory .
docker run -i -v memory-data:/app/data mcp-engram-memory
NuGet library (embed the engine in your own .NET app)
dotnet add package McpEngramMemory.Core --version 1.2.0
See examples/ for ready-to-use config files.
Memory Graph Visualizer
The built-in D3.js graph viewer lets you explore your memory graph interactively.
Generate a snapshot (call this MCP tool from any AI assistant):
get_graph_snapshot → save the JSON → open visualization/memory-graph.html
Features:
- Force-directed layout — related memories cluster together, typed edges (elaborates, contradicts, depends_on, …) shown in distinct neon colors
- Lifecycle colors — STM nodes amber, LTM nodes blue; cluster summaries marked with a dashed ring
- Convex-hull cluster overlays — cluster membership visible at a glance
- Search & highlight — type in the search bar to instantly dim non-matching nodes and pulse-highlight matches in gold;
‹ ›buttons orEnter / Shift+Enterto cycle through results - Zoom / pan / rotate —
+/−/⊡buttons; scroll to zoom; right-click drag to rotate the whole graph - Fractal density overlay — zooms out reveal a quadtree density map color-coded by lifecycle state
- Connected-only filter — hide isolated nodes to focus on the linked knowledge graph
- Drag-and-drop JSON loading — drop a snapshot file directly onto the viewer
The snapshot file is not committed (it's personal memory data). Generate a fresh one any time with get_graph_snapshot.
Tool Profiles
Control how many tools are exposed with MEMORY_TOOL_PROFILE:
| Profile | Tools | What's included |
|---|---|---|
minimal |
17 | Core CRUD + composite + admin + multi-agent — recommended starting point (default) |
standard |
41 | Adds graph (+auto-link), lifecycle (+consolidation), clustering, intelligence, memory-diffusion kernel, spectral retrieval |
full |
65 | Everything including expert routing, debate, synthesis, benchmarks |
At a Glance
| Metric | Value |
|---|---|
| MCP tools | 65 (profiles: 17 / 41 / 65) |
| Retrieval | Hybrid BM25 + vector with synonym expansion, cascade retrieval, MMR diversity, auto-PRF |
| Embedding | bge-micro-v2 (384-dim, ONNX, MIT license, runs locally, concurrent inference) |
| Best recall | 0.792 realworld dataset, 0.771 scale dataset (hybrid mode) |
| Search latency | ~2.7 ms production, ~0.04 ms benchmark |
| Storage | JSON (default) or SQLite (WAL mode) |
| Frameworks | net8.0, net9.0, net10.0 |
| Tests | 865 non-MSA net8 tests across 49 files |
| CI/CD | GitHub Actions: build + test on push, nightly MSA benchmarks |
System Layers
| Layer | Stability | Components |
|---|---|---|
| Core | Stable | Storage, Embeddings, Retrieval, Lifecycle, Graph |
| Advanced | Stable | Clustering, Multi-Agent Sharing, Intelligence |
| Orchestration | Maturing | Expert Routing (HMoE), Debate, Benchmarks |
AI Assistant Setup
Model execution belongs to the host harness, not the Engram server: expert profiles route to persona-backed memory namespaces, while the host model reasons over the retrieved evidence. See Model and Reasoning Routing for canonical task tiers, the current Codex model mapping, reasoning escalation rules, and ready-to-use profiles.
Copy the reference harness for your tool — each includes recall/store/routing patterns:
| Tool | Harness File | MCP Config |
|---|---|---|
| Claude Code | examples/CLAUDE.md → ~/.claude/CLAUDE.md |
examples/claude-code.json |
| GitHub Copilot | examples/copilot-instructions.md → .github/ |
examples/vscode-copilot.json |
| Google Gemini | GEMINI.md → workspace root |
Gemini CLI config |
| OpenAI Codex | examples/AGENTS.md → project root |
Codex config |
Claude Code users: Route memory sub-agents to Sonnet (
model: "sonnet") and utility sub-agents to Haiku (model: "haiku") to maximize your subscription. See the harness for details.
For step-by-step setup prompts, see AI Assistant Setup.
Cost-Optimized Usage (Claude Code)
| Tier | Model | What runs here |
|---|---|---|
| Main thread | Opus | Coding, architecture, reasoning, decisions |
| Memory sub-agents | Sonnet (model: "sonnet") |
All engram MCP tool calls: search, store, dispatch, link, merge |
| Utility sub-agents | Haiku (model: "haiku") |
Codebase exploration, file searches, grep research, simple lookups |
Opus thinks, Sonnet remembers, Haiku explores.
MCP Tools (65)
| Group | Tools | Description |
|---|---|---|
| Core Memory | store_memory, store_batch, search_memory, delete_memory |
Vector CRUD with namespace isolation, batch import, and lifecycle-aware search |
| Composite | remember, recall (with spectralMode), reflect, get_context_block |
High-level wrappers with auto-dedup, auto-linking, expert routing, context assembly, and graph-aware spectral re-ranking on recall (default auto) |
| Knowledge Graph | link_memories, unlink_memories, get_neighbors, traverse_graph, auto_link_namespace |
Directed graph with 7 relation types, multi-hop BFS, and similarity-based auto-link densification |
| Clustering | create_cluster, update_cluster, store_cluster_summary, get_cluster, list_clusters |
Semantic grouping with auto-computed centroids |
| Lifecycle | promote_memory, memory_feedback, deep_recall, decay_cycle, run_consolidation, configure_decay |
State transitions (STM/LTM/archived), spectral decay diffusion, and topology-driven sleep consolidation |
| Memory Diffusion | compute_diffusion_basis, diffusion_stats, invalidate_diffusion, spectral_recall |
Graph-Laplacian eigenbasis primitive shared by decay, consolidation, and retrieval; standalone graph-aware retrieval |
| Intelligence | detect_duplicates, find_contradictions, merge_memories, uncollapse_cluster, list_collapse_history |
Dedup, contradiction detection, merge, collapse reversal |
| Expert Routing | dispatch_task, create_expert, get_domain_tree, link_to_parent |
HMoE semantic routing with 3-level domain tree |
| Multi-Agent | cross_search, share_namespace, unshare_namespace, list_shared, whoami |
Namespace sharing, permissions, cross-namespace RRF search |
| Debate | consult_expert_panel, map_debate_graph, resolve_debate, purge_debates |
Multi-perspective analysis with debate tracking |
| Synthesis | synthesize_memories |
Map-reduce synthesis via local SLM (Ollama by default; ONNX Runtime GenAI is opt-in via SYNTHESIS_BACKEND=onnx) |
| Accretion | get_pending_collapses, collapse_cluster, dismiss_collapse, trigger_accretion_scan |
DBSCAN cluster detection and two-phase summarization |
| Admin | get_memory, cognitive_stats, get_metrics, reset_metrics |
Inspection, system-wide statistics, and latency metrics |
| Maintenance | rebuild_embeddings, compression_stats |
Re-embed entries and storage diagnostics |
| Benchmarks | run_benchmark, run_agent_outcome_benchmark, run_live_agent_outcome_benchmark, compare_live_agent_outcome_artifacts |
IR quality validation, proxy memory-condition comparison, live-model memory A/B benchmarking, and artifact-to-artifact diff reporting |
Full tool documentation: MCP Tools Reference
Environment Variables
| Variable | Default | Description |
|---|---|---|
MEMORY_TOOL_PROFILE |
minimal |
Tool profile: minimal (17), standard (41), full (65) |
AGENT_ID |
default |
Agent identity for multi-agent namespace sharing |
MEMORY_STORAGE |
json |
Storage backend: json, sqlite, or sqlserver |
MEMORY_SQLITE_PATH |
data/memory.db |
SQLite database path (when MEMORY_STORAGE=sqlite) |
MEMORY_SQLSERVER_CONNECTION |
required | SQL Server connection string (when MEMORY_STORAGE=sqlserver) |
MEMORY_SQLSERVER_SCHEMA |
dbo |
SQL Server schema name (when MEMORY_STORAGE=sqlserver) |
MEMORY_MAX_NAMESPACE_SIZE |
unlimited | Max entries per namespace |
MEMORY_MAX_TOTAL_COUNT |
unlimited | Max total entries across all namespaces |
NuGet / GitHub Packages
The core engine is available as a NuGet package for embedding in your own .NET applications:
# nuget.org
dotnet add package McpEngramMemory.Core --version 1.2.0
# GitHub Packages
dotnet add package McpEngramMemory.Core --version 1.2.0 \
--source https://nuget.pkg.github.com/wyckit/index.json
using McpEngramMemory.Core.Services;
using McpEngramMemory.Core.Services.Storage;
var persistence = new PersistenceManager();
var embedding = new OnnxEmbeddingService();
var index = new CognitiveIndex(persistence);
// Store
var vector = embedding.Embed("The capital of France is Paris");
var entry = new CognitiveEntry("fact-1", vector, "default", "The capital of France is Paris", "facts");
index.Upsert(entry);
// Search
var results = index.Search(embedding.Embed("French capital"), "default", k: 5);
Documentation
| Doc | Description |
|---|---|
| First 5 Minutes | Store, close, recall — the whole loop |
| Cheat Sheet | One-page quick reference |
| MCP Tools Reference | Full documentation for all 65 tools |
| Architecture | System design, retrieval pipeline, data flow |
| Services | All services with descriptions |
| Internals | Retrieval, quantization, persistence deep dive |
| Project Structure | File tree and module organization |
| AI Assistant Setup | Step-by-step setup prompts for each tool |
| Sample Prompts | Power prompts and usage patterns |
| Benchmarks | IR quality results and mode selection guide |
| MRCR v2 Benchmark | Long-context A/B (full context vs. hybrid retrieval) via Claude CLI subscription |
| Testing | Test coverage breakdown and current CI coverage |
Build & Test
cd mcp-engram-memory
dotnet build
dotnet test # full suite, including slower MSA benchmark cases
Tech Stack
- .NET 8/9/10, C#
- ModelContextProtocol 1.0.0
- FastBertTokenizer 0.4.67
- Microsoft.ML.OnnxRuntime 1.23.0
- bge-micro-v2 ONNX (384-dim, MIT license)
- Microsoft.Data.Sqlite 8.0.11
- xUnit (tests)
License
MIT
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