🧠 four-opencode-brain

Unified brain plugin for opencode — single SQLite database for RAG search, memory, and knowledge base.

Features

• Hybrid Search — FTS5 full-text + vec0 vector search with RRF fusion
• Memory — Session-scoped notes, decisions, patterns, errors, diary entries
• Knowledge Base — Problem-centric entries with confidence gating and review lifecycle
• Auto-Ingest — Indexes project files on startup (git repos only)
• TUI Status Bar — Live spinner, progress, and completion indicators
• Content-Hash Dedup — Skips unchanged files automatically

Installation

# Clone and install
git clone https://github.com/four-bytes/four-opencode-brain
cd four-opencode-brain
bun install && bun run build

# Register globally (required — TUI slot plugin)
opencode plugin install . -g

Or via GitHub dependency in opencode.json:

{
  "plugin": [
    "github:four-bytes/four-opencode-brain"
  ]
}

• Hybrid Search — FTS5 full-text + vec0 vector search with RRF fusion
• Memory — Session-scoped notes, decisions, patterns, errors, diary entries
• Knowledge Base — Problem-centric entries with confidence gating and review lifecycle
• Auto-Ingest — Indexes project files on startup (git repos only)
• TUI Status Bar — Live spinner, progress, and completion indicators
• Content-Hash Dedup — Skips unchanged files automatically

Installation

Quick Start

After installation, the brain auto-ingests your project on startup (git repos only). You can also:

# In opencode
/brain ingest .           # Index current directory
/brain search "function"  # Search indexed code

Tools

Tool	Description
brain_search	Unified FTS5+vec0 hybrid search across docs, memories, knowledge
brain_ingest	Index files/directories with content-hash dedup
brain_reindex	Rebuild vec0 vector index from chunks
brain_memory	CRUD for memories — add, search, list, forget, diary, get
brain_kb_add	Add/update knowledge entries (draft by default)
brain_kb_get	Get knowledge entry + occurrences + revisions
brain_kb_record	Record occurrence outcome (fixed, failed, workaround, observed)
brain_kb_review	Update review state (draft → reviewed → accepted)
brain_kb_search	FTS5 search knowledge entries
brain_kb_stats	Knowledge store statistics

Configuration

Env Var	Default	Description
BRAIN_AUTO_INGEST	true	Auto-index on startup (git repos only)
BRAIN_DEBUG	unset	Enable debug logging to stderr

Requirements

• Bun ≥ 1.0
• opencode with plugin support
• vec0 SQLite extension (bundled for linux-x64, linux-arm64, darwin-x64, darwin-arm64)

Architecture

src/
├── ingest/       File walker, chunker, embed, symbol extraction
├── search/       FTS5 + vec0 hybrid search with RRF fusion
├── memory/       Session/project-scoped notes (SQLite)
├── knowledge/    Problem-centric entries (confidence + review)
├── hooks/        System prompt + auto-capture triggers
├── embed/        Vec0 extension loader + embedding pipeline
├── status.ts     Unified status bar + toast updates
├── tui.tsx       SolidJS status bar component (theme-aware)
└── shared.ts     Shared constants

License

Apache-2.0 © Four Bytes / Four Flames GmbH & Co. KG

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