Installation
Add Backpack to your code agent with one command. The -s user flag installs it globally so backpack is available in every project.
Recommended: Backpack App (free cloud account)
Sign up for a free account at app.backpackontology.com, then run:
claude mcp add backpack-app -s user -- npx backpack-app
On first run, a browser window opens for sign-in. After that, it's automatic. Your knowledge syncs across devices and you can share with your team.
Backpack Local (offline, private)
Prefer to keep everything on your machine? No account needed:
claude mcp add backpack-local -s user -- npx backpack-local
You can always move to Backpack App later by telling your code agent "sync my backpack to the cloud".
Restart your code agent to activate.
How to use it
Just talk naturally. No commands to learn.
Remember something
"Remember that Acme Corp is on the Enterprise tier, main contact is Sarah Chen"
"Start an ontology for our hiring process"
Find something
"What's in my backpack about Acme Corp?"
"Search backpack for anything related to compliance"
See the big picture
"Show me my knowledge graph"
"What's in my backpack?"
Backpack Local vs App
Backpack Local stores everything as JSON files on your computer at ~/.local/share/backpack/ontologies/. Nothing leaves your machine.
Backpack App stores your knowledge in the cloud. Access from any device, share with your team, and use the web-based graph visualizer at app.backpackontology.com.
Syncing to Cloud
Already using Backpack Local? Tell your code agent:
"Sync my backpack to the cloud"
This uploads all your local ontologies to Backpack App. Then switch your MCP config to use backpack-app instead of backpack.
Editing ontologies
Click any node in the graph visualizer to see its properties. You can:
- Edit property values inline
- Add new properties
- Change node types
- Delete nodes and relationships
- Rename ontologies
Changes save automatically.
Graph visualizer
Local: run npx backpack-viewer
Cloud: visit app.backpackontology.com
Pan, zoom, click nodes to inspect, search across all properties. Changes made via your code agent appear in real time.
Sharing
Share ontologies with teammates by email. Choose viewer or editor permissions. If the person doesn't have an account yet, they'll get access automatically when they sign up.
Auto-capture
Backpack automatically installs hooks that review your code agent conversations and save meaningful knowledge. No setup needed — it's on by default.
To disable, remove the backpack hooks from .claude/settings.json.
MCP tools
Your code agent uses these automatically. You don't need to call them directly.
| Action | Tool |
|---|
| See what's in the backpack | backpack_list, backpack_describe |
| Add a new ontology | backpack_create |
| Find something | backpack_search, backpack_list_nodes |
| Get full details | backpack_get_node, backpack_get_neighbors |
| Add or update knowledge | backpack_add_node, backpack_update_node, backpack_add_edge |
| Bulk import | backpack_import_nodes |
| Clean up | backpack_remove_node, backpack_remove_edge, backpack_delete |
CLI commands
| Command | What it does |
|---|
npx backpack-ontology | Start local MCP server |
npx backpack-app | Start cloud MCP server |
npx backpack-sync | Upload local ontologies to cloud |
npx backpack-viewer | Open graph visualizer |
Limits
These limits apply to Backpack App. Backpack Local has no enforced limits beyond your disk space.
| Resource | Limit |
|---|
| Storage (Free) | 1 GB |
| Storage (Teams) | 10 GB |
| Ontology name | 255 characters, alphanumeric with spaces, hyphens, underscores, periods |
| Description | 1,000 characters |
| Nodes per ontology | 50,000 |
| Edges per ontology | 100,000 |
| Properties per node | 100 keys |
| Property value | 10,000 characters |
| Request body | 10 MB |
Privacy & telemetry
The open source MCP server collects anonymous usage statistics (tool counts, session duration). No content, names, or personal data is ever collected.
Opt out: export DO_NOT_TRACK=1
Full policy: PRIVACY.md