Memory Tokens

Benched.ai Editorial Team

Memory tokens are dedicated tokens reserved in a prompt for storing persistent assistant memory (user preferences, tasks) separate from transient conversation.

Design Patterns

Pattern	Token Budget	Use Case
Key–value JSON blob	200	Small persona data
Vector retrieved snippet	100–300	Long-term project details
Structured table	400	CRM contact info

Trade-offs

More memory improves personalization but raises cost/token.
Stale memories cause outdated suggestions; need aging mechanism.

Current Trends (2025)

Memory summarization runs daily to condense tokens by 3×.
Per-user memory tokens encrypted with PII vault keys.
Dynamic allocation allocates more tokens for power users.

Implementation Tips

Expire memories older than 90 days unless pinned.
Separate safety-critical memories (bans) from preferences.
Monitor average memory token count per user over time.