Letta-style editable memory blocks for OpenCode.

This plugin is experimental. The core idea - giving the agent persistent, self-editable memory blocks - is adapted from Letta. Specifially, the plugin follows Letta's shared memory blocks pattern - the markdown files on disk are shared state that every OpenCode session can read and write.

Think of it as AGENTS.md with a harness. OpenCode supports rules via AGENTS.md and custom instruction files - this plugin is similar in spirit, but adds structure (scoped blocks with metadata and size limits), dedicated tools for memory operations, and prompting that encourages the agent to actively maintain its own memory. The content is similar; the scaffolding around it is what's different.

For background on the memory concept, see Letta's docs on memory and memory blocks.

• Persistent memory - Information survives across sessions and context compaction
• Shared across sessions - Global blocks shared across all projects, project blocks shared across sessions in that codebase
• Self-editing - The agent can read and modify its own memory with dedicated tools
• System prompt injection - Memory blocks appear in the system prompt, always in-context
• Journal - Append-only entries with semantic search for capturing insights, decisions, and discoveries across sessions

• OpenCode v1.0.115 or later

Add to your OpenCode config (~/.config/opencode/opencode.json):

{
  "plugin": ["opencode-agent-memory"]
}

Restart OpenCode and you're ready to go.

Optionally, pin to a specific version for stability:

{
  "plugin": ["opencode-agent-memory@0.2.0"]
}

OpenCode fetches unpinned plugins from npm on each startup; pinned versions are cached and require a manual version bump to update.

If you want to customize or contribute:

git clone https://github.com/joshuadavidthomas/opencode-agent-memory ~/.config/opencode/opencode-agent-memory
mkdir -p ~/.config/opencode/plugin
ln -sf ~/.config/opencode/opencode-agent-memory/src/plugin.ts ~/.config/opencode/plugin/memory.ts

The plugin gives the agent 3 tools for managing memory:

You interact with memory by editing the markdown files directly or asking the agent to update its memory.

When the journal is enabled, the agent gets 3 additional tools:

Journal entries are append-only markdown files with YAML frontmatter, stored in ~/.config/opencode/journal/. Each entry records which project, model, provider, agent, and session it was written from. Semantic search uses local embeddings (all-MiniLM-L6-v2) - no data leaves your machine.

Three blocks are seeded on first run:

These are just starting points. Create whatever blocks make sense for your workflow - debugging-notes, api-preferences, learned-patterns, etc.

• Global blocks: ~/.config/opencode/memory/*.md
• Project blocks: .opencode/memory/*.md (auto-gitignored)

Each block is a markdown file with YAML frontmatter:

All fields have defaults for graceful degradation, but description is essential - without it, the agent gets a generic fallback and won't know how to use the block effectively. See Letta's docs on the importance of the description field.

The journal is opt-in. Enable it in ~/.config/opencode/agent-memory.json:

{
  "journal": {
    "enabled": true
  }
}

You can optionally suggest tags to guide the agent's classification:

{
  "journal": {
    "enabled": true,
    "tags": [
      { "name": "perf", "description": "Performance optimization work" },
      { "name": "debugging", "description": "Debugging sessions and findings" }
    ]
  }
}

Tags are free-form strings - the agent can use any tag, not just the suggested ones. Suggested tags appear in the system prompt to provide guidance.

The memory architecture and philosophical framing are adapted from Letta (formerly MemGPT), a framework for building LLM agents with editable long-term memory.

Also worth exploring: private-journal-mcp by Jesse Vincent, which gives Claude a private journaling capability to process feelings and thoughts. His blog post about it explores similar territory around AI self-reflection and persistent inner experience.

Contributions are welcome! Here's how to set up for development:

git clone https://github.com/joshuadavidthomas/opencode-agent-memory
cd opencode-agent-memory
bun install

Then symlink the plugin to your OpenCode config:

mkdir -p ~/.config/opencode/plugin
ln -sf "$(pwd)/src/plugin.ts" ~/.config/opencode/plugin/memory.ts

opencode-agent-memory is licensed under the MIT license. See the LICENSE file for more information.

opencode-agent-memory is not built by, or affiliated with, the OpenCode team.

OpenCode is ©2025 Anomaly.