Mycel is a knowledge base that agents maintain and humans trust. Connect Claude or any MCP agent — it files, links, and prunes your wiki while you watch it grow live. Every agent edit is reversible. Every source stays yours.
docker compose up · your Postgres, your markdown, your keys ·
no vendor can read a word
The wiki is a persistent, compounding artifact. The cross-references are already there. The contradictions have already been flagged. The synthesis already reflects everything you've read.
— Andrej Karpathy, the LLM Wiki pattern. Mycel is a production implementation of this pattern — with the safety rails the folder-of-files version can't have.
Independent project. Not affiliated with or endorsed by Andrej Karpathy.
That brilliant analysis your AI wrote last Tuesday? Gone, three hundred messages up. Conversations are where synthesis goes to die.
Retrieval pipelines piece the same fragments together on every single question. Nothing accumulates. Nothing compounds.
Notion and Obsidian assume a human does the gardening. Nobody does the gardening. Your vault is a graveyard of good intentions.
Three verbs, straight from the LLM Wiki pattern — industrialized.
Point Claude Desktop, Claude Code, or any MCP client at your Mycel server. The agent reads your KB schema on arrival and becomes a disciplined librarian — 16 tools, full parity with the human editor.
mcp: read · search · file · link · lintDrop in sources — the agent integrates them across pages, auto-links concepts, flags contradictions, and surfaces orphan pages and unwritten references as ghost nodes on the graph.
lint_kb → orphans · ghosts · contradictionsEvery edit streams to your screen live. Every agent change is grouped, attributed, and one-click reversible. Bulk deletions wait for your approval. Trust isn't a vibe here — it's a schema.
revert_group · approval gate · full historyKarpathy's pattern runs on discipline. Mycel runs on guarantees — because it owns the database under the markdown.
Agent reorganized 40 notes badly at 3am? One click restores all of them. Append-only history, group revert, per-block attribution.
The #1 fear of agent-managed knowledge, solved structurally.Sources are marked kind: raw and the server refuses agent writes to them. Synthesis can be wrong; your originals can't be.
Enforced by the server — not by prompt engineering.Force-directed, real-time, draggable. Ghost nodes show what you reference but haven't written — your knowledge frontier, visualized.
Zero external JS dependencies. It's 4KB of physics.Postgres full-text + pgvector semantic, fused with RRF. New notes are searchable the second they're saved. Nonsense queries return nothing.
Agents that can't find what they wrote are useless.Export to plain markdown with stable block anchors, edit anywhere — even in Obsidian — and re-import without losing history or links.
A knowledge base you can leave is one you can trust.The block editor is engineered around IME composition — Korean, Japanese, and Chinese input never breaks mid-syllable, even during live agent sync.
Most AI editors get this wrong. We tested with 한글 first.| Mycel | DIY files + agent | Notion AI | RAG chatbots | |
|---|---|---|---|---|
| Agent maintains the wiki | Yes — 16 MCP tools | Yes | Assists only | No wiki |
| Undo an agent's whole session | One click | git, maybe | No | — |
| Immutable sources, enforced | Server-enforced | By discipline | No | — |
| Live view while agents work | Real-time | Reload files | Partial | — |
| Built-in health checks (lint) | Orphans · ghosts · contradictions | Prompt it yourself | No | — |
| Your data, your server | Self-hosted | Yes | Their cloud | Usually theirs |
| Lossless export | Markdown + anchors | It is files | Lossy | — |
The core is open and self-hosted forever. Paid tiers buy you the gardener, not the garden.
For hackers and note-hoarders
Open core · AGPL
For people whose notes make money
or $149/year — 2 months free
For teams growing a shared brain
then $8/seat · Enterprise: talk to us
First 500 licenses only. Price locks before we plant the next feature. Counter is real.
Prices in USD. Self-hosted plans are licenses — your data never touches our servers. VAT handled at checkout.
Five minutes from docker compose up to an agent filing its first note into your graph.