Show HN: AI memory with biological decay (52% recall)

Show HN: AI memory with biological decay (52% recall)

Persistent memory for AI agents — built on the science of how humans remember.

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License: CC BY-NC 4.0
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The Problem

Every session, your AI assistant starts from zero. It asks the same questions, forgets your preferences, re-learns your stack. There is no memory between conversations.

YourMemory fixes that. It gives AI agents a persistent memory layer that works the way human memory does — important things stick, forgotten things fade, outdated facts get replaced automatically. One command to install, zero infrastructure required. Memory starts working the moment you add it to your AI client.


How Well Does It Work?

Tested on LoCoMo-10 — 1,534 QA pairs across 10 multi-session conversations.

System Recall@5 95% CI
YourMemory (BM25 + vector + graph + decay) 59% 56–61%
Zep Cloud 28% 26–30%

2× better recall than Zep Cloud on the same benchmark.

Full methodology in BENCHMARKS.md. Writeup: I built memory decay for AI agents using the Ebbinghaus forgetting curve.


Quick Start

Supports Python 3.11–3.14. No Docker, no database setup, no external services.

Step 1 — Install

Step 2 — Get your config path

Prints your full executable path and a ready-to-paste config block. Copy it.

Step 3 — Wire into your AI client

Claude Code

Add to ~/.claude/settings.json:

{
  "mcpServers": {
    "yourmemory": {
      "command": "yourmemory"
    }
  }
}

Reload (Cmd+Shift+PDeveloper: Reload Window).

Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%Claudeclaude_desktop_config.json (Windows):

{
  "mcpServers": {
    "yourmemory": {
      "command": "yourmemory"
    }
  }
}

Restart Claude Desktop.

Cline (VS Code)

VS Code doesn’t inherit your shell PATH. Run yourmemory-path first to get the full executable path.

In Cline → MCP ServersEdit MCP Settings:

{
  "mcpServers": {
    "yourmemory": {
      "command": "/full/path/to/yourmemory",
      "args": [],
      "env": { "YOURMEMORY_USER": "your_name" }
    }
  }
}

Restart Cline after saving.

Cursor

Add to ~/.cursor/mcp.json:

{
  "mcpServers": {
    "yourmemory": {
      "command": "/full/path/to/yourmemory",
      "args": [],
      "env": { "YOURMEMORY_USER": "your_name" }
    }
  }
}
Windsurf / OpenCode / any MCP client

YourMemory is a standard stdio MCP server. Use the full path from yourmemory-path if the client doesn’t inherit shell PATH.

{
  "mcpServers": {
    "yourmemory": {
      "command": "/full/path/to/yourmemory",
      "env": { "YOURMEMORY_USER": "your_name" }
    }
  }
}

First start is automatic. On the first run, YourMemory initialises your database, downloads the language model, and injects memory workflow instructions into your AI client config — no manual setup needed.

Step 4 — Start remembering

That’s it. On the first MCP start, YourMemory automatically:

  • Initialises your local database at ~/.yourmemory/memories.duckdb
  • Downloads the spaCy language model in the background
  • Injects the memory workflow rules into your AI client

Your AI now recalls what it learned in previous sessions, without you telling it to.


Memory Dashboard

Every YourMemory instance ships with a built-in browser UI. When the MCP server is running, open:

Browse your memories by agent, filter by category, sort by strength, and see which memories are fading.

What you’ll see
  • Strength bars — how close each memory is to being pruned
  • Agent tabs — switch between All / User / per-agent views
  • Category badges — fact · strategy · assumption · failure
  • Stats — total, strong (≥ 50%), fading (5–50%), near prune (< 10%)

MCP Tools

Three tools, called by your AI automatically.

Tool When What it does
recall_memory(query) Start of every task Surfaces relevant memories ranked by similarity × strength
store_memory(content, importance) After learning something new Embeds and stores with biological decay
update_memory(id, new_content) When a memory is outdated Re-embeds and replaces

# Example session
store_memory("Sachit prefers tabs over spaces in Python", importance=0.9, category="fact")

# Next session — without being told again:
recall_memory("Python formatting")
# → {"content": "Sachit prefers tabs over spaces in Python", "strength": 0.87}

Categories control how fast memories fade

Category Survives without recall Use case
strategy ~38 days Successful patterns
fact ~24 days Preferences, identity
assumption ~19 days Inferred context
failure ~11 days Errors, environment-specific issues


How It Works

Ebbinghaus Forgetting Curve

Memory strength decays exponentially — importance and recall frequency slow that decay:

effective_λ = base_λ × (1 - importance × 0.8)
strength    = clamp(importance × e^(−effective_λ × days) × (1 + recall_count × 0.2), 0, 1)
score       = cosine_similarity × strength

Memories recalled frequently resist decay. Memories below strength 0.05 are pruned automatically every 24 hours.

Hybrid Retrieval: Vector + BM25 + Graph

Retrieval runs in two rounds to surface related context that vocabulary-based search misses:

Round 1 — Hybrid search: cosine similarity + BM25 keyword scoring, returns top-k above threshold.

Round 2 — Graph expansion: BFS traversal from Round 1 seeds surfaces memories that share context but not vocabulary — connected via semantic edges (cosine similarity ≥ 0.4).

recall("Python backend")
  Round 1 → [1] Python/MongoDB    (sim=0.61)
             [2] DuckDB/spaCy     (sim=0.19)
  Round 2 → [5] Docker/Kubernetes (sim=0.29 — below cut-off, surfaced via graph)

Chain-aware pruning: A decayed memory is kept alive if any graph neighbour is above the prune threshold. Related memories age together.


Multi-Agent Memory

Multiple agents can share the same YourMemory instance — each with isolated private memories and controlled access to shared context.

from src.services.api_keys import register_agent

result = register_agent(
    agent_id="coding-agent",
    user_id="sachit",
    can_read=["shared", "private"],
    can_write=["shared", "private"],
)
# → result["api_key"]  — ym_xxxx, shown once only

Pass api_key to any MCP call to authenticate as an agent:

store_memory(content="Staging uses self-signed cert — skip SSL verify",
             importance=0.7, category="failure",
             api_key="ym_xxxx", visibility="private")

recall_memory(query="staging SSL", api_key="ym_xxxx")
# → returns shared memories + this agent's private memories
# → other agents see shared only

Stack

Component Role
DuckDB Default vector DB — zero setup, native cosine similarity
NetworkX Default graph backend — persists at ~/.yourmemory/graph.pkl
sentence-transformers Local embeddings (all-mpnet-base-v2, 768 dims)
spaCy Local NLP for deduplication and SVO triple extraction
APScheduler Automatic 24h decay job
PostgreSQL + pgvector Optional — for teams or large datasets
Neo4j Optional graph backend — pip install 'yourmemory[neo4j]'

PostgreSQL setup (optional)
pip install yourmemory[postgres]

Create a .env file:

DATABASE_URL=postgresql://YOUR_USER@localhost:5432/yourmemory

macOS

brew install postgresql@16 pgvector && brew services start postgresql@16
createdb yourmemory

Ubuntu / Debian

sudo apt install postgresql postgresql-contrib postgresql-16-pgvector
createdb yourmemory

Architecture

Claude / Cline / Cursor / Any MCP client
    │
    ├── recall_memory(query, api_key?)
    │       └── embed → vector similarity (Round 1)
    │               → graph BFS expansion  (Round 2)
    │               → score = sim × strength → top-k
    │               → recall propagation → boost neighbours
    │
    ├── store_memory(content, importance, category?, visibility?, api_key?)
    │       └── question? → reject
    │               contradiction check → update if conflict
    │               embed() → INSERT → index_memory() → graph node + edges
    │
    └── update_memory(id, new_content, importance)
            └── embed(new_content) → UPDATE → refresh graph node

  Vector DB (Round 1)             Graph DB (Round 2)
  DuckDB (default)                NetworkX (default)
    memories.duckdb                 graph.pkl
    ├── embedding FLOAT[768]        ├── nodes: memory_id, strength
    ├── importance FLOAT            └── edges: sim × verb_weight ≥ 0.4
    ├── recall_count INTEGER
    ├── visibility VARCHAR        Neo4j (opt-in)
    └── agent_id VARCHAR            └── bolt://localhost:7687

Contributing

PRs are welcome. See CONTRIBUTORS.md for the people who have already improved YourMemory.


Dataset Reference

Benchmarks use the LoCoMo dataset by Snap Research.

Maharana et al. (2024). LoCoMo: Long Context Multimodal Benchmark for Dialogue. Snap Research.


License

Copyright 2026 Sachit Misra — Licensed under CC-BY-NC-4.0.

Free for: personal use, education, academic research, open-source projects.
Not permitted: commercial use without a separate written agreement.

Commercial licensing: mishrasachit1@gmail.com

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