> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cascadeflow.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Quality and Routing

> TypeScript quality validation, semantic checks, complexity detection, routers, rules, and domain configuration.

`CascadeAgent` combines quality validation with pre-routing, tool capability checks, tiers, domains, and custom rules.

## Quality Validation

```typescript theme={null}
import { QualityValidator } from '@cascadeflow/core';

const validator = new QualityValidator({
  minConfidence: 0.7,
  minWordCount: 10,
  useLogprobs: true,
  fallbackToHeuristic: true,
  strictMode: false,
  useAlignmentScoring: true,
  minAlignmentScore: 0.15,
});
```

The package also exports `ProductionConfidenceEstimator`, `ResponseAnalyzer`, `QueryResponseAlignmentScorer`, and `ComplexityDetector` for direct use.

## Semantic Validation

Install the optional ML runtime:

```bash theme={null}
npm install @cascadeflow/ml @huggingface/transformers
```

Enable it through agent quality configuration:

```typescript theme={null}
const agent = new CascadeAgent({
  models,
  quality: {
    useSemanticValidation: true,
    semanticThreshold: 0.5,
  },
});
```

Or use the checker directly:

```typescript theme={null}
import { SemanticQualityChecker } from '@cascadeflow/core';

const checker = new SemanticQualityChecker();
if (await checker.isAvailable()) {
  const result = await checker.checkSimilarity(query, response);
  console.log(result.similarity, result.passed);
}
```

## Routers

| Router         | Purpose                                            |
| -------------- | -------------------------------------------------- |
| `PreRouter`    | Decide whether to cascade or route directly        |
| `ToolRouter`   | Filter and rank tool-capable models                |
| `TierRouter`   | Apply user-tier constraints                        |
| `DomainRouter` | Detect a domain and select domain-specific routing |
| `RouterChain`  | Compose routing decisions                          |

`CascadeAgent` creates and coordinates these routers from `AgentConfig` and `RunOptions`.

## Domain Configuration

```typescript theme={null}
import { CascadeAgent, Domain } from '@cascadeflow/core';

const agent = new CascadeAgent({
  models,
  domainConfigs: {
    [Domain.MATH]: {
      drafter: 'gpt-4o-mini',
      verifier: 'gpt-4o',
      threshold: 0.85,
    },
  },
  enableDomainDetection: true,
});
```

The package exports built-in strategies and domain configurations through `BUILT_IN_STRATEGIES` and `BUILTIN_DOMAIN_CONFIGS`.

## Rule Engine

`RuleEngine` applies workflow, tenant, channel, user-tier, and KPI context before model execution.

```typescript theme={null}
const result = await agent.run('Handle this request', {
  userTier: 'premium',
  workflow: 'support',
  tenantId: 'tenant-123',
  channel: 'web',
  kpiFlags: { priority: 'high' },
});
```

Provide `ruleEngineConfig` or a custom `ruleEngine` in `AgentConfig` when the built-in routing rules are not sufficient.