markdown-hierarchical-memory

An implementation of markdown-hierarchical-memory-spec.md v1.

• MCP server (src/mdmem/): The mechanical execution layer providing file read/write, frontmatter management, a wikilink graph, keyword search with graph expansion, optimistic concurrency control (§16), bidirectional link consistency checks (§12), and a change log (§10/§17). Semantic judgments such as cohesion and importance (§9) are not implemented.

• Claude Code subagent (.claude/agents/memory-manager.md): The Manager Agent defined in §10 of the specification. This is the component that makes semantic judgments by calling MCP tools.

Scope

• Of the features in §15, only link graph + keyword search is supported (embedding vector search is not implemented. It can be added by replacing _score in src/mdmem/search.py).

• The Manager Agent's decision-making logic does not make LLM calls internally within the server. The caller (Claude Code) is expected to make the decisions and pass the results as parameters to tool calls.

Related MCP server: AIBrain

Setup

pip install -e .
python -m pytest tests/

Registering with Claude Code

Copy .mcp.json.example to .mcp.json and replace <ABSOLUTE_PATH_TO_THIS_REPO> with the absolute path to this repository (.mcp.json is excluded by .gitignore because it contains a personal local path):

cp .mcp.json.example .mcp.json
# Edit .mcp.json and fill in the path

After restarting Claude Code (or reloading the MCP configuration), the mdmem server will be enabled, and the memory-manager subagent in .claude/agents/memory-manager.md will be able to call the mcp__mdmem__* tool set.

claude mcp list

This command can be used to verify that mdmem is recognized.

Registering with Cursor

• MCP: .cursor/mcp.json (points to the same MDMEM_ROOT as Claude Code's .mcp.json)

• Manager Agent: .cursor/skills/memory-manager/SKILL.md

After restarting Cursor (or reloading mdmem in Settings → Tools & MCP), you can share and use the same memory/ directory with Claude Code.

Directory Structure

memory/
 ├── index.md          # Pure registry (§14)
 ├── projects/
 ├── concepts/
 └── archive/
      └── _manager_log.md   # Change log (§10/§17)

The actual path of memory/ can be changed with the MDMEM_ROOT environment variable (default: memory/ in the current directory).

Main MCP Tools

All write tools accept expected_updated and return ConflictError if it differs from the value observed during reading (§16).

Known Limitations

• Narrow race condition in concurrent writes: Optimistic locking with expected_updated only guarantees the sequence of "read, then validate, then write" within a single process. When Cursor and Claude Code share the same MDMEM_ROOT (a situation actually observed during development of this repository), there is a theoretical possibility that two processes read the same file at nearly the same time, both pass the check, and one update overwrites the other. This is not critical, but it is not a problem when writes are performed by a single process only.

• Embedding vector search is not implemented (see the Scope section).

• id only accepts ^[A-Za-z0-9_-]+$ (because it is used directly in file paths).

License

MIT