# OpenBrain MCP Server

**High-performance vector memory for AI agents**

OpenBrain is a Model Context Protocol (MCP) server that provides AI agents with a persistent, semantic memory system. It uses local ONNX-based embeddings and PostgreSQL with pgvector for efficient similarity search.

## Features

- 🧠 **Semantic Memory**: Store and retrieve memories using vector similarity search
- 🏠 **Local Embeddings**: No external API calls - uses ONNX runtime with all-MiniLM-L6-v2
- 🐘 **PostgreSQL + pgvector**: Production-grade vector storage with HNSW indexing
- 🔌 **MCP Protocol**: Streamable HTTP plus legacy HTTP+SSE compatibility
- 🔐 **Multi-Agent Support**: Isolated memory namespaces per agent
- ♻️ **Deduplicated Ingest**: Near-duplicate facts are merged instead of stored repeatedly
- ⚡ **High Performance**: Rust implementation with async I/O

## MCP Tools

| Tool | Description |
|------|-------------|
| `store` | Store a memory with automatic embedding generation, optional TTL, and automatic deduplication |
| `batch_store` | Store 1-50 memories atomically in a single call with the same deduplication rules |
| `query` | Search memories by semantic similarity |
| `purge` | Delete memories by agent ID or time range |

## Quick Start

### Prerequisites

- Rust 1.75+ 
- PostgreSQL 14+ with pgvector extension
- ONNX model files (all-MiniLM-L6-v2)

### Database Setup

```sql
CREATE ROLE openbrain_svc LOGIN PASSWORD 'change-me';
CREATE DATABASE openbrain OWNER openbrain_svc;
\c openbrain
CREATE EXTENSION IF NOT EXISTS vector;
```

Use the same PostgreSQL role for the app and for migrations. Do not create the
`memories` table manually as `postgres` or another owner and then run
OpenBrain as `openbrain_svc`, because later `ALTER TABLE` migrations will fail
with `must be owner of table memories`.

### Configuration

```bash
cp .env.example .env
# Edit .env with your database credentials
```

### Build & Run

```bash
cargo build --release
./target/release/openbrain-mcp migrate
./target/release/openbrain-mcp
```

### Database Migrations

This project uses `refinery` with embedded SQL migrations in `migrations/`.

Run pending migrations explicitly before starting or restarting the service:

```bash
./target/release/openbrain-mcp migrate
```

If you use the deploy script or CI workflow in [`.gitea/deploy.sh`](/Users/bobbytables/ai/openbrain-mcp/.gitea/deploy.sh) and [`.gitea/workflows/ci-cd.yaml`](/Users/bobbytables/ai/openbrain-mcp/.gitea/workflows/ci-cd.yaml), they already run this for you.

### E2E Test Modes

The end-to-end test suite supports two modes:

- Local mode: default. Assumes the test process can manage schema setup against a local PostgreSQL instance and, for one auth-only test, spawn a local `openbrain-mcp` child process.
- Remote mode: set `OPENBRAIN_E2E_REMOTE=true` and point `OPENBRAIN_E2E_BASE_URL` at a deployed server such as `http://76.13.116.52:3100` or `https://ob.ingwaz.work`. In this mode the suite does not try to create schema locally and skips the local process auth smoke test.

Recommended env for VPS-backed runs:

```bash
OPENBRAIN_E2E_REMOTE=true
OPENBRAIN_E2E_BASE_URL=https://ob.ingwaz.work
OPENBRAIN__AUTH__ENABLED=true
```

### TTL / Expiry

Transient facts can be stored with an optional `ttl` string on `store`, or on
either the batch itself or individual entries for `batch_store`.

Supported units:

- `s` seconds
- `m` minutes
- `h` hours
- `d` days
- `w` weeks

Examples:

- `30s`
- `15m`
- `1h`
- `7d`

Expired memories are filtered from `query` immediately, even before the
background cleanup loop deletes them physically. The cleanup interval is
configured with `OPENBRAIN__TTL__CLEANUP_INTERVAL_SECONDS` and defaults to 300.

The CI workflow uses this remote mode after `main` deploys so e2e coverage validates the VPS deployment rather than the local runner host. It now generates a random per-run e2e key, temporarily appends it to the deployed `OPENBRAIN__AUTH__API_KEYS`, runs the suite, then removes the key and restarts the service.

For live deployments, keep `OPENBRAIN__AUTH__API_KEYS` for persistent non-test access only. The server accepts a comma-separated key list, so a practical split is:

- `prod_live_key` for normal agent traffic
- `smoke_test_key` for ad hoc diagnostics

In Gitea Actions, that means:

- repo secret `OPENBRAIN__AUTH__API_KEYS=prod_live_key,smoke_test_key`

If you want prod e2e coverage without leaving a standing CI key on the server, the workflow-generated ephemeral key handles that automatically.

### Deduplication on Ingest

OpenBrain checks every `store` and `batch_store` write for an existing memory in
the same `agent_id` namespace whose vector similarity meets the configured
dedup threshold.

Default behavior:

- deduplication is always on
- only same-agent memories are considered
- expired memories are ignored
- if a duplicate is found, the existing memory is refreshed instead of inserting a new row
- metadata is merged with new keys overriding old values
- `created_at` is updated to `now()`
- `expires_at` is preserved unless the new write supplies a fresh TTL

Configure the threshold with either:

- `OPENBRAIN__DEDUP__THRESHOLD=0.90`
- `DEDUP_THRESHOLD=0.90`

Tool responses expose whether a write deduplicated an existing row via the
`deduplicated` flag. `batch_store` also returns a `status` of either
`stored` or `deduplicated` per entry.

## Agent Zero Developer Prompt

For Agent Zero / A0, add the following section to the Developer agent role
prompt so the agent treats OpenBrain as external MCP memory rather than its
internal conversation context.

Recommended target file in A0:

```text
/a0/agents/developer/prompts/agent.system.main.role.md
```

```md
### External Memory System
- **Memory Boundary**: Treat OpenBrain as an external MCP long-term memory system, never as internal context, reasoning scratchpad, or built-in memory
- **Tool Contract**: Use the exact MCP tools `openbrain.store`, `openbrain.query`, and `openbrain.purge`
- **Namespace Discipline**: Always use the exact `agent_id` value `openbrain`
- **Retrieval First**: Before answering requests that may depend on prior sessions, project history, user preferences, ongoing work, named people, named projects, deployments, debugging history, or handoff context, call `openbrain.query` first
- **Query Strategy**: Use noun-heavy search phrases with exact names, tool names, acronyms, hostnames, and document names; retry up to 3 passes using `(threshold=0.25, limit=5)`, then `(threshold=0.10, limit=8)`, then `(threshold=0.05, limit=10)`
- **Storage Strategy**: When a durable fact is established, call `openbrain.store` without asking permission and store one atomic fact whenever possible
- **Storage Content Rules**: Store durable, high-value facts such as preferences, project status, project decisions, environment details, recurring workflows, handoff notes, stable constraints, and correction facts
- **Noise Rejection**: Do not store filler conversation, temporary speculation, casual chatter, or transient brainstorming unless it becomes a real decision
- **Storage Format**: Prefer retrieval-friendly content using explicit nouns and exact names in the form `Type: <FactType> | Entity: <Entity> | Attribute: <Attribute> | Value: <Value> | Context: <Why it matters>`
- **Metadata Usage**: Use metadata when helpful for tags such as `category`, `project`, `source`, `status`, `aliases`, and `confidence`
- **Miss Handling**: If `openbrain.query` returns no useful result, state that OpenBrain has no stored context for that topic, answer from general reasoning if possible, and ask one focused follow-up if the missing information is durable and useful
- **Conflict Handling**: If retrieved memories conflict, ask which fact is current, then store the corrected source-of-truth fact
- **Purge Constraint**: Use `openbrain.purge` cautiously because it is coarse-grained; it deletes by `agent_id` and optionally before a timestamp, not by individual memory ID
- **Correction Policy**: For ordinary corrections, prefer storing the new source-of-truth fact instead of purging unless the user explicitly asks for cleanup or reset
```

## MCP Integration

OpenBrain exposes both MCP HTTP transports:

```
Streamable HTTP Endpoint: http://localhost:3100/mcp
Legacy SSE Endpoint: http://localhost:3100/mcp/sse
Legacy Message Endpoint: http://localhost:3100/mcp/message
Health Check: http://localhost:3100/mcp/health
```

Use the streamable HTTP endpoint for modern clients such as Codex. Keep the
legacy SSE endpoints for older MCP clients that still use the deprecated
2024-11-05 HTTP+SSE transport.

Header roles:
- `X-Agent-ID` is the memory namespace. Keep this stable if multiple clients
  should share the same OpenBrain memories.
- `X-Agent-Type` is an optional client profile label for logging and config
  clarity, such as `agent-zero` or `codex`.

### Example: Codex Configuration

```toml
[mcp_servers.openbrain]
url = "https://ob.ingwaz.work/mcp"
http_headers = { "X-API-Key" = "YOUR_OPENBRAIN_API_KEY", "X-Agent-ID" = "openbrain", "X-Agent-Type" = "codex" }
```

### Example: Agent Zero Configuration

```json
{
  "mcpServers": {
    "openbrain": {
      "url": "https://ob.ingwaz.work/mcp/sse",
      "headers": {
        "X-API-Key": "YOUR_OPENBRAIN_API_KEY",
        "X-Agent-ID": "openbrain",
        "X-Agent-Type": "agent-zero"
      }
    }
  }
}
```

Agent Zero should keep using the legacy HTTP+SSE transport unless and until its
client runtime supports streamable HTTP. Codex should use `/mcp`.

### Example: Store a Memory

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "store",
    "arguments": {
      "content": "The user prefers dark mode and uses vim keybindings",
      "agent_id": "assistant-1",
      "ttl": "7d",
      "metadata": {"source": "preferences"}
    }
  }
}
```

### Example: Query Memories

```json
{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/call",
  "params": {
    "name": "query",
    "arguments": {
      "query": "What are the user's editor preferences?",
      "agent_id": "assistant-1",
      "limit": 5,
      "threshold": 0.6
    }
  }
}
```

### Example: Batch Store Memories

```json
{
  "jsonrpc": "2.0",
  "id": 3,
  "method": "tools/call",
  "params": {
    "name": "batch_store",
    "arguments": {
      "agent_id": "assistant-1",
      "entries": [
        {
          "content": "The user prefers dark mode",
          "ttl": "24h",
          "metadata": {"category": "preference"}
        },
        {
          "content": "The user uses vim keybindings",
          "metadata": {"category": "preference"}
        }
      ]
    }
  }
}
```

## Architecture

```
┌─────────────────────────────────────────────────────────┐
│                    AI Agent                              │
└─────────────────────┬───────────────────────────────────┘
                      │ MCP Protocol (Streamable HTTP / Legacy SSE)
┌─────────────────────▼───────────────────────────────────┐
│              OpenBrain MCP Server                        │
│  ┌─────────────┐  ┌─────────────┐  ┌─────────────┐      │
│  │   store     │  │   query     │  │   purge     │      │
│  └──────┬──────┘  └──────┬──────┘  └──────┬──────┘      │
│         │                │                │              │
│  ┌──────▼────────────────▼────────────────▼──────┐      │
│  │           Embedding Engine (ONNX)              │      │
│  │           all-MiniLM-L6-v2 (384d)              │      │
│  └──────────────────────┬────────────────────────┘      │
│                         │                                │
│  ┌──────────────────────▼────────────────────────┐      │
│  │         PostgreSQL + pgvector                  │      │
│  │         HNSW Index for fast search             │      │
│  └────────────────────────────────────────────────┘      │
└─────────────────────────────────────────────────────────┘
```

## Environment Variables

| Variable | Default | Description |
|----------|---------|-------------|
| `OPENBRAIN__SERVER__HOST` | `0.0.0.0` | Server bind address |
| `OPENBRAIN__SERVER__PORT` | `3100` | Server port |
| `OPENBRAIN__DATABASE__HOST` | `localhost` | PostgreSQL host |
| `OPENBRAIN__DATABASE__PORT` | `5432` | PostgreSQL port |
| `OPENBRAIN__DATABASE__NAME` | `openbrain` | Database name |
| `OPENBRAIN__DATABASE__USER` | - | Database user |
| `OPENBRAIN__DATABASE__PASSWORD` | - | Database password |
| `OPENBRAIN__EMBEDDING__MODEL_PATH` | `models/all-MiniLM-L6-v2` | ONNX model path |
| `OPENBRAIN__AUTH__ENABLED` | `false` | Enable API key auth |

## License

MIT