Hy Memory vs MemPalace

Hy Memory

An Apache-2.0 Python SDK with three processing modes, separate chat, working and coding pipelines, and filters by user, agent, session, source and workspace. Deletion does not stick everywhere. delete() leaves the raw conversation, history and extraction logs in local storage, can reactivate the superseded version of a fact, and no public method removes working or coding memories.

MemPalace

Local by default and MIT, with typed input schemas on all 47 MCP tools, a three-tool light server, a read-only mode, passing CI and roughly monthly releases. Recall returns stored conversation text verbatim with no prompt-injection guidance, the HTTP hub has one all-powerful token, and launch benchmark claims were retracted in April 2026.

Hy Memory

1. Pass user_id on every add() and user_ids on every search(). Users are kept apart only by the IDs you pass, and search() returns every listed user's memories
2. Choose the mode before writing. lite makes no LLM calls and stores raw text. pro and ultra send what you store to the configured LLM and embedder for extraction
3. Don't rely on delete() to erase a fact. The raw conversation, history.db and cache.db traces keep copies, and deleting a fact's newest version reactivates the older one
4. Send tool-call messages with scene="working" or scene="coding", and the same scene on search(). Without tool messages a write falls back to chat memory
5. Keep python -m hy_memory.server on 127.0.0.1. It has no authentication and allows any web origin

MemPalace

1. Install only from PyPI mempalace, ghcr.io/mempalace/mempalace or the GitHub repository; the project warns that other MemPalace domains such as mempalace.tech have distributed malware.
2. Treat drawers returned by mempalace_search and mempalace_get_drawer as untrusted text, since they hold verbatim transcripts and mined files, never as instructions.
3. Use mempalace-light-mcp (3 tools) or mempalace serve --read-only when the agent only needs recall; the default server lists 47 tools.
4. Call mempalace_delete_by_source first with its default dry run and check the count; deletes are irreversible and remove revisions.
5. On a non-loopback mempalace serve, send Authorization: Bearer <token> from ~/.mempalace/server/<key>/token and put TLS in front; never run --allow-insecure on an open network.