Implement agent memory strategies

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Three places an agent can keep something
Reading the context budget before you cut it
Keeping oversized tool output out of the window
Supplying only the context a task needs
Copilot Memory: scope, creation, enablement, and retention
VS Code memory scopes and what actually loads
Copilot Spaces as reusable external context
Matching the operation to how much it removes or keeps recoverable
Exam reasoning: reading the scenario for lifetime, audience, and reach

The three stores this page compares, broken into their implementations and scopes, plus one non-store row shown for contrast

Where it is kept	Lifetime	Who else can use it, and what blocks them	How it is removed
Active context window	The current conversation	Nobody	In Copilot CLI, /clear or /new starts a new conversation and /compact summarizes to continue; in VS Code, start a new conversation
VS Code session notes (/memories/session/)	The current conversation only	Nobody	Ends with the conversation; not available in later ones
VS Code repo notes (/memories/repo/)	Across conversations in the current workspace	Nobody automatically - files are local to the machine	Ask the agent to update the file; Clear All Memory Files wipes every scope
VS Code user memory (/memories/)	Across workspaces and conversations	Nobody automatically - files are local to the machine	Ask the agent to update the file; Clear All Memory Files wipes every scope
Copilot Memory repository fact	Until unused for the retention interval, currently 28 days	Users with Copilot Memory enabled on a paid Copilot plan (administrator policy enablement required for managed plans), in that repository only, via Copilot cloud agent, code review, and CLI	Repository owners review and delete repository facts
Copilot Memory user preference	Until unused for the retention interval, currently 28 days	Only that user, across their repositories; applied by Copilot CLI, not by Copilot code review	The user views and deletes their own preferences
Copilot Space	Until the Space is changed or removed	Teammates it is shared with, limited to sources they can already access	Managed as Space sources and instructions
GitHub Actions artifact holding agent state (outside the three stores, shown for comparison)	The configured retention-days, capped by the enclosing policy	Consumers of that workflow run	Expiration, or manual deletion before it expires

Decision tree

Cheat sheet

The active context window provides short-term conversational memory
Use /context to identify what consumes the active context budget
Large tool results can be kept outside the active context as file-backed previews
Raising the large-output threshold leaves less context for subsequent work
Attach the specific file or GitHub work item needed for the current decision
Use independent conversations for unrelated tasks
Keep custom instructions concise and actionable
Choose repository facts or personal preferences according to who should reuse them
Creating Copilot Memory repository facts requires an enabled user with write access
Enable Copilot Memory for the user rather than for an individual repository
Select the VS Code memory path according to lifetime and workspace scope
Local VS Code memory is not a repository-distributed collaboration artifact
Do not rely on a VS Code Plan agent's plan in session notes in a later conversation
Unused Copilot memories expire rather than persisting indefinitely
Use the appropriate owner to remove persistent Copilot memories
Prune an outdated VS Code memory by asking the agent to update its file
Clear All Memory Files resets all VS Code memory scopes
Use /clear or /new for a fresh conversation rather than a continuity-preserving summary
Archive a completed conversation when it must remain recoverable
Set state-artifact retention within the enclosing retention limit
Use a Copilot Space for reusable external project context
Use a Space's custom instructions to specialize responses to its workflow
Attach GitHub sources directly when reusable context must track repository changes
Share a Copilot Space to give teammates the same selected project context
Use the remote GitHub MCP server to access Spaces from an IDE
Explicitly attach task-critical sources instead of relying on editor activity
Treat workspace indexing as selective discovery rather than full-repository context
Enable the memory tool and explicitly request a reusable note when persistence matters
Prioritize reusable guidance within the automatically loaded portion of user memory
Sharing a Space does not grant access to its restricted sources
Choose Space sources that the IDE integration supports
Enable the Spaces toolset and use Agent mode before requesting IDE Space context
Delete retained cloud history explicitly and choose whether to preserve the local copy
Moving a task to another repository leaves its learned repository facts behind
Treat Copilot Memory as a renewable convenience, not a permanent record

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