DriftGuard

Some reliability problems don’t announce themselves. They accumulate — small behavioral shifts, growing memory deviations, patterns that move outside their baseline one session at a time. By the time they’re visible, they’ve been building for weeks. DriftGuard watches for them.

What Drift Looks Like

Drift is harder to catch than a crash because nothing breaks outright. Instead:

An agent that used to respond in 800ms now consistently takes 2.5 seconds — not slow enough to trigger a timeout alert, but degraded
Memory patterns shift over successive sessions — the agent’s context grows slightly faster each day without explanation
Behavior becomes less consistent: the same input produces noticeably different outputs across sessions, indicating something in the agent’s operating environment is changing

Standard monitoring misses all of this. DriftGuard doesn’t.

What DriftGuard Does

Establishes a behavioral baseline for each monitored agent
Tracks deviations from baseline across memory patterns, response characteristics, and context behavior
Flags long-horizon erosion before it crosses the threshold into active failure
Surfaces trends with the context to understand what’s changing and when it started

Signals DriftGuard Monitors

Context Drift

Changes in how the agent’s context behaves over time:

Context growth rate (tokens per session vs. baseline)
Compaction frequency and efficiency
Memory retention patterns across sessions

Baseline Deviation

Comparison of current agent behavior against established baseline:

Response latency distribution
Output consistency across similar inputs
Tool usage patterns
Error rate trends

Memory Integrity Posture

Whether the agent’s persistent memory state is remaining coherent:

Memory growth velocity
Anomalous retrieval patterns
State consistency across sessions

Quick Start

# Establish a baseline for an agent (run once)
acme driftguard baseline --agent my-agent-name

# Start drift monitoring
acme driftguard watch --agent my-agent-name

# View current drift status
acme driftguard status

# Compare current behavior to baseline
acme driftguard compare --agent my-agent-name

Output

DriftGuard Status
==================
Timestamp: 2026-03-09 15:42:31 UTC

Monitored Agents: 2

  pipeline-agent       📊 STABLE     Deviation: +2%  (within normal range)
  support-agent-prod   ⚠ DRIFTING   Deviation: +18%  ← ATTENTION

support-agent-prod — Drift Detail:
  Baseline established: 2026-02-20 (18 days ago)
  
  Context growth rate:  +23%  ⚠  (baseline: 420 tok/session → current: 516 tok/session)
  Response latency:     +12%  ↑  (baseline: 840ms → current: 941ms)
  Compaction frequency: +31%  ⚠  (was compacting 1.2×/session → now 1.6×/session)
  Output consistency:   -5%   ↓  (within range)

  Trend: 18-day upward trajectory. Started 2026-03-01.
  
  Recommendation:
    Review agent configuration changes from 2026-03-01 onwards.
    High compaction frequency suggests context growth outpacing budget.
    Consider increasing context budget or reviewing memory management.

Establishing Baselines

DriftGuard needs a stable operating period to establish a reliable baseline. When to baseline:

After a new agent deployment once it’s been running for a few days
After a major configuration change to reset expectations
Periodically (recommended: quarterly) to account for intentional evolution

# Establish baseline (captures current 7-day behavior window)
acme driftguard baseline --agent my-agent-name

# Baseline with custom window
acme driftguard baseline --agent my-agent-name --window 14d

# Reset baseline (use when you've intentionally changed agent behavior)
acme driftguard baseline --agent my-agent-name --reset

Drift Thresholds

DriftGuard uses configurable thresholds. Defaults are conservative — flag early, before problems compound.

# ~/.acme/driftguard.yaml
thresholds:
  context_growth_rate: 15     # % deviation from baseline before warning
  response_latency: 20        # % deviation from baseline
  compaction_frequency: 25    # % deviation from baseline
  output_consistency: 15      # % drop from baseline before warning

monitoring:
  check_interval: 3600        # seconds between drift checks (default: 1h)
  trend_window: 7             # days of history for trend analysis

Integration with Sentinel and Agent911

DriftGuard operates on a longer time horizon than Sentinel:

Sentinel catches active failures (minutes)
DriftGuard catches slow degradation (days to weeks)

Both feed into Agent911. DriftGuard findings appear in the Agent911 snapshot when drift thresholds are exceeded.

CLI Reference

# Baseline management
acme driftguard baseline --agent <name>
acme driftguard baseline --agent <name> --reset
acme driftguard baseline list

# Status and comparison
acme driftguard status
acme driftguard status --agent <name>
acme driftguard compare --agent <name>

# Monitoring
acme driftguard watch --agent <name>
acme driftguard watch --all

# History
acme driftguard history --agent <name>
acme driftguard history --agent <name> --days 30

Next Steps

Sentinel

Active failure detection — the short-horizon complement to DriftGuard.

Agent911

DriftGuard findings surface in the Agent911 snapshot when thresholds are exceeded.

Getting Started

Free Tools

Runtime Protection

Control & Recovery

Governance

Architecture

Support

DriftGuard Overview

DriftGuard

What Drift Looks Like

What DriftGuard Does

Signals DriftGuard Monitors

Context Drift

Baseline Deviation

Memory Integrity Posture

Quick Start

Output

Establishing Baselines

Drift Thresholds

Integration with Sentinel and Agent911

CLI Reference

Next Steps

Sentinel

Agent911

​DriftGuard

​What Drift Looks Like

​What DriftGuard Does

​Signals DriftGuard Monitors

​Context Drift

​Baseline Deviation

​Memory Integrity Posture

​Quick Start

​Output

​Establishing Baselines

​Drift Thresholds

​Integration with Sentinel and Agent911

​CLI Reference

​Next Steps

Sentinel

Agent911

DriftGuard

What Drift Looks Like

What DriftGuard Does

Signals DriftGuard Monitors

Context Drift

Baseline Deviation

Memory Integrity Posture

Quick Start

Output

Establishing Baselines

Drift Thresholds

Integration with Sentinel and Agent911

CLI Reference

Next Steps