Browse / Alternatives / Obsidian
Open source Obsidian alternatives for AI agents
3 alternatives to Obsidian. 3 have an interface an agent can drive. 3 are open source.
| Listing | License | Agent interface | Reach | Effort | Last activity |
|---|---|---|---|---|---|
| SiYuan | AGPL-3.0 | MCP server, from the builder | 9 of 10 jobs | Config only | Sep 3, 2026 |
| Trilium Notes | AGPL-3.0 | API and MCP server, from the builder | 8 of 10 jobs | Config only | Sep 3, 2026 |
| Tolaria | AGPL-3.0 | MCP server, from the builder | 4 of 8 jobs | Not adaptable | Sep 3, 2026 |
SiYuan
Block-based local-first knowledge base whose Go kernel ships a 30-plus tool MCP server and HTTP API.
Free · PRO Features: $64 lifetime · Subscription: $148 per year
- you want block references and databases like Notion, stored locally, with an agent that can query them by SQL
- you run a Docker kernel on your NAS and want daily notes written by an agent from the terminal
- Plugins and marketplace, AI writing UI
- AGPL-3.0
- Since v3.7.0 the Docker image needs an explicit serve subcommand
- Official cloud sync and some features are paid; third-party S3/WebDAV sync needs PRO Features
- Docker web UI is protected only by the access auth code unless OIDC is set
Trilium Notes
Hierarchical note tree with attributes and scripting, driven by the ETAPI REST API and an in-repo MCP route.
Free
- you want a deeply nested personal or team knowledge tree that an agent can populate through a stable REST API
- you outgrew flat markdown folders and want attributes, relations, and saved searches
- Scripting and widgets
- Sync and protected (encrypted) notes
- AGPL-3.0
- The desktop app and server versions must match for sync; disable auto-updates on the server when using TriliumDroid
- ETAPI needs a token created in the UI (Options > ETAPI) or from POST /etapi/auth/login with the instance password
- MCP route tool names were not read; they come from the core LLM tool registry (packages/core llm/tools)
Tolaria
Files-first markdown second brain with git built in and an in-repo MCP server for Claude Code and Codex.
Free
- you want your notes as plain markdown in git and an agent that can search and write them from Claude Code
- you run a 10,000-note personal vault and want keyboard-first navigation with AI on the side
- Git commit, push, and history
- In-app AI chat over note context
- Inbox and web-resource capture
1 more job is undetermined.
- AGPL-3.0-or-later
- The MCP server talks to the running desktop app over a websocket bridge; open_note and vault attach need the app open
- No paid or hosted edition; sync is whatever git remote you choose
Questions
Is there an open source alternative to Obsidian?
Yes. All 3 listings here are open source: SiYuan (AGPL-3.0), Trilium Notes (AGPL-3.0), Tolaria (AGPL-3.0).
Which Obsidian alternatives have an MCP server?
SiYuan, Trilium Notes and Tolaria have MCP servers from their builders.
Which Obsidian alternative can an agent do the most with?
SiYuan: 9 of 10 recorded jobs reachable. Jobs differ by listing, so read each list before you choose.
Listings come from reading each repo and its docs. Reach counts the jobs an agent can do through the stated interface, and each listing page shows the evidence. Order follows fit. For agents: Markdown · JSON