Mushroomdb MCP server

mushroomdb

The graph that stays true — and knows who's allowed to see it.

mushroomdb is the data layer for agents that reason over entities. It is an embedded Rust graph database in which a relationship is a schema declaration: write a rule once, and every write derives, maintains and retracts the matching edges, each one carrying the rule, the score and the values that produced it. An agent reaches it over MCP — fifteen tools on an entity store — or you embed it as a Rust library, a Python module, or a sidecar beside your own service. Four questions are what it exists for: why are these two related (explainassociation, answered with the evidence rather than an assertion), what did that look like then (edgesat, the edges a node had at any past commit), what would this change do (whatif, computed without writing anything), and who may see it** (query with a role, so one graph answers differently per caller). Local-first: a directory on disk, no account, no endpoint, no model call in the write path unless you enable embeddings.

ingest-git stays supported as a data source: commits, pull requests, files and authors become entities with rule-derived relationships, which is what makes a ticket↔commit link a rule rather than a script.

Deprecated in 0.6.4: the code-graph door — the explore, map, context, impact,

owners, why and sync tools, the three grep/edit hooks, and the plugin's coding-assistant

positioning. It still works and is still tested; it is removed in 0.7. See

Deprecations.

Pre-1.0 alpha — APIs and formats may change between minor versions.

Docs · Changelog · Issues

Quick start

npx mushroomdb install --db ./memory

One command writes the /mushroom skill, an MCP server listing the fifteen-tool association surface, and the session hooks. Then a worked flow, four tool calls:

upsert_entity  →  create_rule  →  find_similar  →  explain_association
  (store)           (link)           (recall)          (explain)

Full tool reference: docs/site/mcp.md.

Shortened. The full README is on GitHub.