title: Hipocampo MCP emoji: 🧠 colorFrom: blue colorTo: purple sdk: docker pinned: false
<p align="center"> <img src="assets/logo.png" alt="Hipocampo" width="180"/> </p> <h1 align="center">Hipocampo</h1> <h3 align="center">Dual-Memory System with Sparse Selective Caching</h3> <p align="center"> Persistent memory for autonomous AI agents · PostgreSQL 17 + pgvector · Hybrid Search · MCP Server </p>⚠️ Transport Note: SSE transport is deprecated since MCP spec 2025-03-26. Hipocampo now uses Streamable HTTP (single endpoint
/mcp) as the recommended remote transport. SSE (/sse) remains available for backward compatibility but will be removed in a future release.
🌐 MCP Server — Live on Hugging Face
Hipocampo runs as a free MCP server on Hugging Face Spaces. Connect from any MCP client:
URL: https://alexbell1-hipocampo-mcp.hf.space/mcp🧪 Interactive Playground: Try saving and searching memories from your browser at https://alexbell1-hipocampo-mcp.hf.space/ — no registration or MCP client needed.
⚠️ Important: The Hugging Face free tier is ephemeral — data is lost on restart/deploy. This instance is intended for testing only. For persistent storage, run Hipocampo locally (see Quick Start) or connect an external database (Neon, Supabase, etc.).
{
"mcpServers": {
"hipocampo": {
"url": "https://alexbell1-hipocampo-mcp.hf.space/mcp",
"type": "streamable-http"
}
}
}Embedding model: sentence-transformers/all-MiniLM-L6-v2 (384 dims) via Hugging Face Inference API (free, no credit card required).
Hipocampo is an advanced dual-memory persistence architecture designed for autonomous AI agents. By maintaining both technical knowledge and user profiling data across sessions, Hipocampo provides a reliable, stateful context that enables agents to learn, adapt, and scale efficiently.
Built on top of PostgreSQL 17 with pgvector, it features BIRE v3.7 — a hybrid retrieval engine combining semantic embeddings (1024d), lexical expansion, and GIN trigram search with dynamic score fusion. Also includes Sparse Selective Caching (SSC) as an experimental pipeline.
💡 Why Prompt Compression?
Hipocampo already reduces context through SSC (selective retrieval). But even the top-5 most relevant memories can consume 500-2000+ tokens when concatenated — a significant portion of any LLM's context window.
Hybrid compression adds a second reduction layer:
- Extractive phase: Removes redundant sentences (filtering by keyword relevance to your query). Reduces generic text by 30-50% instantly, with no API calls.
- LLM phase: Summarizes technical/code content using the same NVIDIA NIM endpoint already used for embeddings. Preserves all code, variable names, and syntax while dropping explanatory verbosity.
- Combined: 20-50% token reduction with near-zero quality loss. A 1500-token memory block becomes 750-1200 tokens — that's real savings on every LLM call.
Real impact: If you call compress_hipocampo before every search_hipocampo → LLM round-trip, you save 200-800 tokens per interaction. At scale (hundreds of queries), this translates to meaningful cost reduction and faster responses.
🚀 Key Features
- Dual-Memory Architecture: Distinct storage layers for technical records (
memoria_vectorial) and user profile data (memory_items), each utilizing 1024-dimensional embeddings. - BIRE v3.7 (default): Hybrid search engine combining NVIDIA embeddings (1024d), query expansion, GIN trigram, and composite scoring — used by all MCP tools.
- SSC (experimental): Alternative four-phase progressive pipeline: Tag Router → pgvector Top-K → GIN Trigram → ILIKE Fallback.
- Logarithmic Checkpointing: Intelligently compresses historical memories based on time decay, shrinking 24-hour granular details into unified 90-day checkpoints.
- Automated Tagging Engine: A robust, Regex-based rule engine that autonomously categorizes and tags records upon persistence.
- Cross-System Vector Search: Unified semantic search across over 1,100 records for deep cross-referencing.
- Hybrid Prompt Compression (v4.0): Two-phase compression pipeline — extractive (sentence-level) for generic text and LLM summarization (via NVIDIA NIM) for technical/code content. Reduces prompt tokens by 20-50% while preserving critical information. Available as
compress_hipocampoMCP tool. - Memory Graph (v4.0): Directed graph of semantic relationships between memories. Link related records, navigate with BFS tree, find shortest paths. Available as
link_hipocampo,graph_hipocampo,path_hipocampoMCP tools. - Memory Hierarchy with Trigger-Based Prevention (v4.1): 🧠🧠 Three-level memory (episodic → semantic → automatic) inspired by human mnemonic consolidation. NEW: Tag memories with contextual triggers (
trigger:php,trigger:chartjs,trigger:tomcat) — when the agent starts working in that context, it searches for matchingautomaticarules and reactivates past errors before making the same mistake. This mirrors the biological hippocampus: a partial cue (project + language) triggers full memory retrieval of the error and its solution. Automatic rules are permanent — never compressed, never deleted.set_nivel_hipocampo(id, nivel)+consolidate_hipocampotools included. - Code Immune System — Regression Protection (v4.2): 🛡️ Prevents agents from breaking code that was working. 3-step cycle: (1) Snapshot functional state before editing, (2) Verify after editing, (3) If something broke → create a permanent
automaticarule capturing the exact cause, symptom, and fix. Uses immune economy: pre-change snapshots are cheapepisodica(auto-compressed if no damage), post-break rules are permanentautomatica. Pre-loaded with fragile file catalog — header.php, conexion.php, utils.php, auth.php, etc. Agents searchtrigger:regression trigger:<file>before every edit to learn what other agents broke before. - Code RAG (v4.0): Index project source code (PHP, JS, TS, Python, SQL) as semantic embeddings. Search with
search_code(query, language)— returns real code snippets with file paths and line numbers, not just summaries. - Exponential Time Decay (v4.0):
final_score = relevance × exp(-λ × days)with λ=0.05 configurable and 20% floor. Recent knowledge naturally outranks old memories. - MMR Diversity Anti-Cluster (v4.3): Maximum Marginal Relevance post-fusion re-ranking prevents dense embedding clusters from monopolizing search results. Iteratively selects results that balance relevance with diversity:
diversity_lambda × relevance - (1-diversity_lambda) × max_similarity_to_selected. Configurable inhipocampo_hybrid_config.json. - Link Weight Decay (v4.3): Exponential weight decay on memory graph links (half-life 90 days). Links that aren't traversed lose strength over time; links <0.01 are pruned.
graph_hipocampo()andpath_hipocampo()auto-reinforce traversed links. Newdecay_hipocampo(dry_run)tool for graph maintenance. Columns:last_accessed,reinforced_at. - Session Memory & Auto-Summarization: Session-isolated save/search. After 20+ saves, Hipocampo auto-generates a consolidated session summary in the background.
- Proactive Context Preloading:
preload_context(project_path)extracts meaningful keywords from the project path, searches relevant memories, and returns a compressed summary — ideal for session start. - Context Budget Awareness:
compress_hipocampoauto-estimates token budget and adjusts k dynamically.budget_ratioparameter gives fine-grained control over output size. - Auto-Linking:
save_hipocampo(..., auto_link=True)auto-discovers semantically similar memories (>0.75 cosine) and createssimilaredges in the memory graph. - HNSW Auto-Recovery:
hipocampo_health()checks the HNSW index on startup and auto-creates it if missing — no more manualCREATE INDEXcommands. - Model Context Protocol (MCP): Native integration via a FastMCP server with 25 tools, exposing seamless read/write capabilities to modern MCP clients (e.g., Claude Desktop, OpenCode).
⚡ Why PostgreSQL + pgvector (Not SQLite)?
You might wonder why Hipocampo uses PostgreSQL 17 with pgvector instead of a lighter stack like SQLite. The answer: hybrid search requires more than vector similarity alone.
Hipocampo's retrieval pipeline combines pgvector (HNSW) for semantic search, pg_trgm (GIN) for lexical expansion, and ILIKE for fallback — fused into a single weighted score. SQLite extensions like sqlite-vec offer vector search, but lack:
- GIN trigram indexes for fuzzy/partial matching
- Full-text + vector hybrid fusion in a single query
- Production-grade HNSW indexing with concurrent writes
- pg_trgm-based query expansion when embeddings alone are insufficient
With ~1,100+ records across two memory tables and growing, Hipocampo needs a database that scales without sacrificing retrieval quality. PostgreSQL + pgvector isn't "heavy" for the sake of it — it's the minimum viable stack to deliver the hybrid accuracy that BIRE and SSC require.
🎯 Use Cases
Error → Learn → Never Repeat (AI Agent Learning Loop)
Hipocampo enables AI agents to learn from mistakes across sessions using a simple cycle:
┌─ 1. SEARCH ─────────────────────────────┐
│ Before executing a command, the agent │
│ searches Hipocampo for similar errors: │
│ search_hipocampo("error <context>") │
└───────────────────┬──────────────────────┘
│
┌─ 2. EXECUTE ──────▼──────────────────────┐
│ If match found → apply known solution │
│ If not → attempt new approach │
└───────────────────┬──────────────────────┘
│
┌─ 3. EVALUATE ─────▼──────────────────────┐
│ Did it fail? Capture: │
│ - error context & exit code │
│ - what was attempted │
│ - what happened │
└───────────────────┬──────────────────────┘
│
┌─ 4. PERSIST ──────▼──────────────────────┐
│ save_hipocampo( │
│ content="Error X: tried Y, result Z", │
│ memory_type="decision", │
│ code="error_<hash>", │
│ categories=["bugfix", "<tool>"] │
│ ) │
└──────────────────────────────────────────┘Real example: An agent tries flatpak install npm and fails. It saves the error to Hipocampo: "npm is a Node.js package manager, not a Flatpak package. Use npm directly." Next time the same command is attempted, the agent finds this record and knows the solution immediately — without repeating the mistake.
Over time, the agent's error knowledge base grows organically. Each failure makes future sessions smarter. This turns Hipocampo from a simple archive into a continuous learning system for AI agents.
🧠 Context-Aware Error Prevention (NEW v4.1) — Proactive, not Reactive
Going beyond reactive lear
…