Purpose-built for agent-heavy workflows
Agentbrain is a local-first vault for Markdown, JSON, and agent-ready context. Use it like a focused notes app, or extend it with self-hosted sync, share links, and an API for agents and other apps.
Early open-source release. Local mode works out of the box. Advanced setup is agent-friendly.
Why agentbrain
The missing layer
I used to use Obsidian heavily, and it can work well with agents that have local file access. But for agent-heavy workflows, Markdown alone was not enough. I kept needing first-class JSON, better ways to build and inspect structured data, share links, and an API for tools that cannot safely or directly write to local files.
Agentbrain keeps the best part of the vault model, files you own, and makes it purpose-built for AI workflows. Markdown handles docs, process, and human-readable context. JSON handles structured data that agents, other AI systems, and applications can reliably use.
What it does
01 / 04
Open a folder and start working. agentbrain keeps your vault as ordinary files on disk, so technical users can inspect, back up, sync, or version it, while non-technical users can simply use the Mac app like a clean, focused workspace.
02 / 04
Markdown is excellent for notes, documentation, workflows, and project context. JSON is essential for agent workflows because it gives AI systems and applications structured data they can read, transform, and reuse without ambiguity.
03 / 04
Not everyone wants to hand-author Markdown or JSON. agentbrain’s builder helps users construct clean documents and structured JSON, while also making it easier to inspect nested data before handing it to another AI system or application.
04 / 04
When you need more than local files, agentbrain adds self-hosted sync, read-only share links, and an HTTP API. It packages the pieces agent workflows need into one purpose-built tool instead of relying on a pile of plugins and workarounds.
Workflow
Download the Mac app, choose a vault folder, and start writing Markdown or building JSON. This path works out of the box and does not require Docker, servers, or command-line setup.
Use Markdown for human-readable docs and JSON for structured state, configs, schemas, workflows, and app data. The builder makes those formats approachable for non-technical users and faster for technical ones.
Agents with local disk access can work directly with the vault files. Agents without disk access, or users who do not want to grant broad filesystem access, can use the API. That matters for tools like Perplexity Computer, and it also opens the door for other applications to talk to agentbrain.
Agent API
Agent-native
Local agents can work directly with agentbrain’s files when disk access is available. For cloud agents, restricted environments, Perplexity Computer, or apps that should not receive broad filesystem access, the HTTP API provides scoped access to the exact vault documents they need.
If-Match to prevent silent overwrites.$ curl "https://sync.example.com/v1/docs?vaultId=agent-vault&path=02_projects/spec.md" \
-H "Authorization: Bearer $AGENT_TOKEN"
{
"path": "02_projects/spec.md",
"contentType": "text/markdown",
"version": "sha256:8b2...",
"content": "# agentbrain spec..."
}Launch shape
Best for most people. Download, open, choose a folder, and start working locally without touching servers or setup scripts.
Recommended first CTA
Best for developers, contributors, and self-hosters. The repo includes the desktop app, sync/API docs, examples, and the implementation details needed to understand or extend the system.
Developer path
Best when you want multi-device sync, share links, remote agent access, or integrations with other apps. If you are not technical, the setup guide is written so you can hand it to Cursor, Claude Code, or Codex.
Optional advanced path
Open source
Start with a local Mac app that feels simple. Grow into a self-hosted agent workspace when you need sync, share links, JSON workflows, or API access.