ADR-373: Budget-Dependent Memory Operator Selection (OAS)

Status: Proposed Date: 2026-07-23 Authors: claude (dream-cycle agent, 2026-07-23) Related: ADR-097 (Federation Budget Circuit Breaker), ADR-088 (LongMemEval Benchmark)

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Context

Kang et al. (arXiv 2607.17545, Jul 2026) show that selecting the memory operation — retain (cheap append), consolidate (expensive summarize), or evict (drop oldest) — based on remaining token budget yields +48% task success under tight-budget conditions compared to a fixed consolidation policy.

Ruflo's @claude-flow/memory module currently runs a background consolidation worker at fixed low priority with no awareness of the caller's remaining token budget. This is a regressive policy: under tight budgets (common in production multi-agent runs) Ruflo triggers the most expensive memory operation (consolidation/summarization) at the worst time.

No existing ADR (085–319) addresses per-call budget-conditional operator dispatch for local memory management.

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Decision

Add a MemoryOperatorSelector to @claude-flow/memory that:

1. Reads remaining budget from the cost-tracker hook (ruflo-cost-tracker event or env var CLAUDE_FLOW_BUDGET_REMAINING) before every memory write operation.
2. Selects operator by threshold:
   • budget > 30%: consolidate — summarize old entries, maintain dense representation
   • 10% < budget ≤ 30%: retain — append only, no summarization
   • budget ≤ 10% or budget unknown: evict — drop oldest entries beyond watermark, no LLM call
3. Exposes opt-in flag --memory-budget-aware (CLI) and memoryBudgetAware: boolean (API); defaults to false until benchmarked in production to avoid regressions.
4. Records operator choice in AgentDB metadata for offline analysis and SONA training.

Thresholds are tunable via claude-flow.config.json → memory.budgetThresholds.

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Implementation Target

File	Change
v3/@claude-flow/memory/src/operators/budget-selector.ts	New: MemoryOperatorSelector class
v3/@claude-flow/memory/src/agentdb/writer.ts	Integrate selector before write path
v3/@claude-flow/cli/src/commands/memory.ts	Add --memory-budget-aware flag
v3/@claude-flow/memory/tests/budget-selector.test.ts	Unit tests; mock cost-tracker

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Consequences

Positive:

• +48% estimated task success under tight budgets (Grade A evidence, Kang et al. 2607.17545)
• Zero-cost evict path eliminates LLM calls when budget is exhausted
• Opt-in default eliminates regression risk

Negative:

• Requires cost-tracker integration; adds coupling between memory and billing modules
• Evict-on-low-budget degrades memory quality when agents run long

Deferred:

• Multi-hop graph traversal (separate gap, higher implementation cost — needs ADR of its own)
• MINJA input validation (security scope, ADR should be in @claude-flow/security)