Presets

Cruel provides five ready-to-use chaos presets that simulate different levels of AI infrastructure stress. Use these to quickly test your application’s resilience.

Available Presets

import { presets } from 'cruel/ai-sdk'

// Five levels of chaos
presets.realistic     // Light chaos for development
presets.unstable      // Medium chaos for CI/staging
presets.harsh         // Heavy chaos for stress testing
presets.nightmare     // Extreme chaos for resilience testing
presets.apocalypse    // Maximum chaos for chaos engineering

Preset Reference

realistic

Light chaos that simulates normal production conditions.

const realistic: CruelChaosOptions = {
  rateLimit: 0.02,              // 2% rate limits
  overloaded: 0.01,             // 1% overload
  delay: [50, 200],             // 50-200ms latency
  slowTokens: [20, 80],         // 20-80ms per token
}

rateLimit

0.02

2% chance of rate limit errors

overloaded

0.01

1% chance of model overload

delay

[50, 200]

50-200ms latency before responses

slowTokens

[20, 80]

20-80ms delay between streamed tokens

Use for:

Development testing
Smoke tests
Verifying basic error handling

unstable

Moderate chaos for staging environments.

const unstable: CruelChaosOptions = {
  rateLimit: 0.1,               // 10% rate limits
  overloaded: 0.05,             // 5% overload
  streamCut: 0.05,              // 5% stream interruptions
  delay: [100, 500],            // 100-500ms latency
  slowTokens: [50, 200],        // 50-200ms per token
}

rateLimit

0.1

10% chance of rate limit errors

overloaded

0.05

5% chance of model overload

streamCut

0.05

5% chance of stream interruption

delay

[100, 500]

100-500ms latency before responses

slowTokens

[50, 200]

50-200ms delay between streamed tokens

Use for:

CI/CD pipelines
Staging environment testing
Integration tests

harsh

Heavy chaos for stress testing.

const harsh: CruelChaosOptions = {
  rateLimit: 0.2,               // 20% rate limits
  overloaded: 0.1,              // 10% overload
  streamCut: 0.1,               // 10% stream interruptions
  contentFilter: 0.02,          // 2% content filter
  delay: [200, 1000],           // 200-1000ms latency
  slowTokens: [100, 500],       // 100-500ms per token
}

rateLimit

0.2

20% chance of rate limit errors

overloaded

0.1

10% chance of model overload

streamCut

0.1

10% chance of stream interruption

contentFilter

0.02

2% chance of content filter errors

delay

[200, 1000]

200-1000ms latency before responses

slowTokens

[100, 500]

100-500ms delay between streamed tokens

Use for:

Stress testing
Load testing
Verifying retry logic

nightmare

Extreme chaos for resilience testing.

const nightmare: CruelChaosOptions = {
  rateLimit: 0.3,               // 30% rate limits
  overloaded: 0.15,             // 15% overload
  streamCut: 0.15,              // 15% stream interruptions
  contentFilter: 0.05,          // 5% content filter
  contextLength: 0.05,          // 5% context length errors
  partialResponse: 0.1,         // 10% partial responses
  delay: [500, 2000],           // 500-2000ms latency
  slowTokens: [200, 1000],      // 200-1000ms per token
  toolFailure: 0.1,             // 10% tool failures
}

rateLimit

0.3

30% chance of rate limit errors

overloaded

0.15

15% chance of model overload

streamCut

0.15

15% chance of stream interruption

contentFilter

0.05

5% chance of content filter errors

contextLength

0.05

5% chance of context length errors

partialResponse

0.1

10% chance of truncated responses

delay

[500, 2000]

500-2000ms latency before responses

slowTokens

[200, 1000]

200-1000ms delay between streamed tokens

toolFailure

0.1

10% chance of tool execution failure

Use for:

Resilience testing
Chaos engineering
Finding edge cases

apocalypse

Maximum chaos for extreme scenarios.

const apocalypse: CruelChaosOptions = {
  rateLimit: 0.4,               // 40% rate limits
  overloaded: 0.2,              // 20% overload
  streamCut: 0.2,               // 20% stream interruptions
  contentFilter: 0.1,           // 10% content filter
  contextLength: 0.1,           // 10% context length errors
  modelUnavailable: 0.1,        // 10% model unavailable
  partialResponse: 0.15,        // 15% partial responses
  corruptChunks: 0.05,          // 5% corrupt chunks
  delay: [1000, 5000],          // 1-5 second latency
  slowTokens: [500, 2000],      // 0.5-2 second per token
  toolFailure: 0.2,             // 20% tool failures
  toolTimeout: 0.1,             // 10% tool timeouts
}

rateLimit

0.4

40% chance of rate limit errors

overloaded

0.2

20% chance of model overload

streamCut

0.2

20% chance of stream interruption

contentFilter

0.1

10% chance of content filter errors

contextLength

0.1

10% chance of context length errors

modelUnavailable

0.1

10% chance of model unavailable errors

partialResponse

0.15

15% chance of truncated responses

corruptChunks

0.05

5% chance of corrupt stream chunks

delay

[1000, 5000]

1-5 second latency before responses

slowTokens

[500, 2000]

0.5-2 second delay between streamed tokens

toolFailure

0.2

20% chance of tool execution failure

toolTimeout

0.1

10% chance of tool timeout

Use for:

Maximum chaos testing
Breaking your app to find limits
Disaster recovery testing

Usage Examples

import { openai } from '@ai-sdk/openai'
import { generateText } from 'ai'
import { cruelModel, presets } from 'cruel/ai-sdk'

const model = cruelModel(openai('gpt-4'), presets.unstable)

const result = await generateText({
  model,
  prompt: 'Hello',
  maxRetries: 3,
})

Customizing Presets

Override specific values while keeping preset defaults:

import { cruelModel, presets } from 'cruel/ai-sdk'
import { openai } from '@ai-sdk/openai'

const model = cruelModel(openai('gpt-4'), {
  ...presets.unstable,
  
  // Override rate limit
  rateLimit: 0.3,
  
  // Add monitoring
  onChaos: (event) => {
    console.log('Chaos:', event.type)
  },
})

Environment-Based Presets

Select preset based on environment:

import { cruelModel, presets } from 'cruel/ai-sdk'
import { openai } from '@ai-sdk/openai'

const CHAOS_PRESETS = {
  development: presets.realistic,
  staging: presets.unstable,
  production: undefined,  // No chaos in prod
} as const

const env = process.env.NODE_ENV as keyof typeof CHAOS_PRESETS
const preset = CHAOS_PRESETS[env]

const model = preset
  ? cruelModel(openai('gpt-4'), preset)
  : openai('gpt-4')

Combining Presets

Merge multiple presets:

import { presets } from 'cruel/ai-sdk'

const custom = {
  ...presets.unstable,
  
  // Add specific failures from harsh
  contentFilter: presets.harsh.contentFilter,
  
  // Add tool chaos from nightmare
  toolFailure: presets.nightmare.toolFailure,
  
  // Custom values
  delay: [75, 350],
}

Testing Strategy

Use presets progressively:

Start with realistic

Verify basic error handling works:

const model = cruelModel(openai('gpt-4'), presets.realistic)

Move to unstable

Test retry logic and resilience:

const model = cruelModel(openai('gpt-4'), presets.unstable)

Try harsh

Stress test with heavy failures:

const model = cruelModel(openai('gpt-4'), presets.harsh)

Challenge with nightmare

Find edge cases and breaking points:

const model = cruelModel(openai('gpt-4'), presets.nightmare)

Break with apocalypse (optional)

Test absolute worst-case scenarios:

const model = cruelModel(openai('gpt-4'), presets.apocalypse)

Real-World Example

import { openai } from '@ai-sdk/openai'
import { generateText } from 'ai'
import { cruelModel, presets } from 'cruel/ai-sdk'

const CHAOS_LEVEL = process.env.CHAOS_LEVEL || 'realistic'

const chaosPresets = {
  realistic: presets.realistic,
  unstable: presets.unstable,
  harsh: presets.harsh,
  nightmare: presets.nightmare,
  apocalypse: presets.apocalypse,
  none: undefined,
} as const

type ChaosLevel = keyof typeof chaosPresets

const preset = chaosPresets[CHAOS_LEVEL as ChaosLevel]

const model = preset
  ? cruelModel(openai('gpt-4'), {
      ...preset,
      onChaos: (event) => {
        console.log(`[${CHAOS_LEVEL}] ${event.type}`, event)
      },
    })
  : openai('gpt-4')

export async function query(prompt: string) {
  return generateText({
    model,
    prompt,
    maxRetries: CHAOS_LEVEL === 'none' ? 0 : 3,
  })
}

Run with different chaos levels:

# Development
CHAOS_LEVEL=realistic npm test

# CI/CD
CHAOS_LEVEL=unstable npm test

# Stress testing
CHAOS_LEVEL=harsh npm run stress-test

# Chaos engineering
CHAOS_LEVEL=nightmare npm run chaos-test

# Production (no chaos)
CHAOS_LEVEL=none npm start

Preset Comparison

Preset	Rate Limits	Overload	Stream Cut	Content Filter	Latency	Use Case
realistic	2%	1%	0%	0%	50-200ms	Development
unstable	10%	5%	5%	0%	100-500ms	CI/Staging
harsh	20%	10%	10%	2%	200-1000ms	Stress Testing
nightmare	30%	15%	15%	5%	500-2000ms	Resilience
apocalypse	40%	20%	20%	10%	1-5 seconds	Max Chaos

TypeScript

import type { CruelChaosOptions } from 'cruel/ai-sdk'
import { presets } from 'cruel/ai-sdk'

// All presets satisfy CruelChaosOptions
const realistic: CruelChaosOptions = presets.realistic
const unstable: CruelChaosOptions = presets.unstable
const harsh: CruelChaosOptions = presets.harsh
const nightmare: CruelChaosOptions = presets.nightmare
const apocalypse: CruelChaosOptions = presets.apocalypse

// Type-safe preset selection
type PresetName = 'realistic' | 'unstable' | 'harsh' | 'nightmare' | 'apocalypse'

function getPreset(name: PresetName): CruelChaosOptions {
  return presets[name]
}

Source Code

Presets are defined in ai-sdk.ts:529-580.

Next Steps

Model Chaos

Learn about all chaos options

Provider Wrapping

Use presets with providers

Tool Chaos

Apply presets to tools

Overview

Back to AI SDK overview

Get Started

Core Concepts

Chaos Types

Resilience Patterns

AI SDK Integration

Advanced

CLI

Available Presets

Preset Reference

realistic

unstable

harsh

nightmare

apocalypse

Usage Examples

Customizing Presets

Environment-Based Presets

Combining Presets

Testing Strategy

Real-World Example

Preset Comparison

TypeScript

Source Code

Next Steps

Model Chaos

Provider Wrapping

Tool Chaos

Overview

Build docs developers (and LLMs) love

Get Started

Core Concepts

Chaos Types

Resilience Patterns

AI SDK Integration

Advanced

CLI

Documentation Index

​Available Presets

​Preset Reference

​realistic

​unstable

​harsh

​nightmare

​apocalypse

​Usage Examples

​Customizing Presets

​Environment-Based Presets

​Combining Presets

​Testing Strategy

​Real-World Example

​Preset Comparison

​TypeScript

​Source Code

​Next Steps

Model Chaos

Provider Wrapping

Tool Chaos

Overview

Build docs developers (and LLMs) love

Available Presets

Preset Reference

realistic

unstable

harsh

nightmare

apocalypse

Usage Examples

Customizing Presets

Environment-Based Presets

Combining Presets

Testing Strategy

Real-World Example

Preset Comparison

TypeScript

Source Code

Next Steps