Assistant: Circuit Breaker & Resilience

The circuit breaker pattern was extended across all adaptive planner LLM call sites in April 2026, providing graceful degradation when LLM providers experience failures, timeouts, or rate limits.

Motivation

The adaptive planner makes many sequential LLM calls (task decomposition, replanning, result evaluation). A single provider outage could cascade through the entire planning pipeline, wasting tokens on doomed requests and producing incoherent partial plans. The circuit breaker prevents this by:

1. Fast-failing after consecutive errors (no waiting on a dead provider)
2. Falling back to alternative models/providers automatically
3. Self-healing by transitioning from open → half-open → closed after a cooldown

Circuit Breaker States

stateDiagram-v2
    [*] --> Closed
    Closed --> Open : N consecutive failures
    Open --> HalfOpen : cooldown elapsed
    HalfOpen --> Closed : success
    HalfOpen --> Open : failure

Configuration

Integration Points

Adaptive Planner

The circuit breaker wraps every LLM call in the adaptive planner:

• decomposeTask() — Task breakdown calls
• evaluateResult() — Result evaluation calls
• replanIfNeeded() — Replanning calls

When a call hits an open circuit breaker, the planner falls back to:

1. Alternative provider — If the primary model has a fallback configured (e.g., openrouter/z-ai/glm-4.5-air:free as fallback for llama/qwen3:30b)
2. Reduced model — A cheaper/faster model that may produce less optimal but functional output
3. Cached result — If the same query type was recently successful, reuse that approach

Session Counter Reset

On a new user message, session error counters are reset with a 2-second delay before LLM retries. This gives transient issues time to resolve without carrying over stale failure state:

// Reset on new user message
session.ErrorCount = 0
time.AfterFunc(2*time.Second, func() {
    // Allow retries after brief cooldown
})

Error Classification

The circuit breaker distinguishes between error types to avoid opening on non-provider issues:

Monitoring

Circuit breaker state changes are logged with the [CIRCUIT] prefix:

[CIRCUIT] Open: provider=openrouter model=glm-4.5-air failures=3 last_error="429 rate limit"
[CIRCUIT] HalfOpen: provider=openrouter model=glm-4.5-air cooldown=60s
[CIRCUIT] Closed: provider=openrouter model=glm-4.5-air probe_success=true

Mission Control displays circuit breaker status in the agent health panel.

Key Files

Cross-References

• Assistant Framework
• Context Optimization — Complementary token efficiency measures
• Planner & Adaptive Planning