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Engra

Common Knowledge: a shared memory library for every team

Ship platform-wide facts once—product docs, runbooks, conventions—and let every workspace merge them into search, recall, and wake-up by default. Read-only for customers; writable only by platform operators.

The problem

Every customer team builds its own memory library for project facts. But some knowledge is universal: how Library / Scope / Topic work, pricing limits, supported MCP tools, or your company's public API contracts. Duplicating those atoms across hundreds of libraries wastes ingest quota and drifts out of date.

Common Knowledge is a single platform-managed library—merged into retrieval by default—so agents pick up shared facts without each team maintaining a copy.

How it works

One row in memory_libraries with library_kind = platform_shared, pointed to by platform_memory_settings.shared_common_library_id. All teams can list and search it; only the platform operations team (the team that owns the library row) can write atoms.

When includeSharedCommonInRetrieval is enabled (default), memory_search and memory_recall on a team library also query Common Knowledge and merge top hits by similarity. memory_wake_up can append a ## Shared common knowledge block when augmentQuery is set. Hits may include source: platform_shared for attribution.

Configuration cascade

Three levels, same pattern as MCP wake/save overrides: • Per library — inherit, on, or off • Per team — override platform default • Platform — default on for new teams

Turn it off for a sensitive library if you need retrieval isolated to team-owned atoms only.

Console and MCP

Platform admins create the library once under Platform admin, then manage atoms like any other library. Other teams see a Shared badge on /dashboard/memory; write UI is hidden.

MCP memory_list_libraries includes the shared library with readOnly: true for non-owner teams. Write tools return memory_library_read_only if a customer key targets the shared library directly.

Deploy checklist

Apply D1 migration 0046, deploy the app and memory-mcp-proxy worker, then POST /api/platform/memory/shared-library once as a platform admin. Full schema and API notes are in the internal memory-libraries doc and the public Common Knowledge guide.