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Model flags let you choose which AI model to use. You can select by tier (Opus, Sonnet, Haiku) or specify an exact model ID.

Cross-Runtime Model Mapping

The same tier flag selects each runtime’s equivalent model:
TierFlagClaude CodeCodex CLI
High--opus / --highclaude-opus-4-7gpt-5.4
Mid--sonnet / --midclaude-sonnet-4-6gpt-5.3-codex
Low--haiku / --lowclaude-haiku-4-5gpt-5.4-mini
Tier flags work the same way regardless of runtime. --opus always gives you the highest-tier model for whichever runtime is active.

Tier Flags

High Tier (Opus)

--opus
flag
Highest-tier model - Most capable, best for complex reasoning
ai --opus task.md
ai --aws --opus
ai --ollama --opus      # Not applicable to Ollama
Equivalent: --highDefault model: claude-opus-4-7Use for:
  • Complex architectural decisions
  • Difficult refactoring
  • Security analysis
  • High-stakes code generation
--high
flag
Alias for --opus
ai --high task.md

Mid Tier (Sonnet)

--sonnet
flag
Mid-tier model - Balanced capability and speed
ai --sonnet task.md
ai --aws --sonnet
Equivalent: --midDefault model: claude-sonnet-4-6Use for:
  • Most coding tasks
  • General development
  • Documentation
  • Code review
--mid
flag
Alias for --sonnet
ai --mid task.md

Low Tier (Haiku)

--haiku
flag
Lowest-tier model - Fastest and most cost-effective
ai --haiku task.md
ai --aws --haiku
ai --ollama --haiku     # Not applicable to Ollama
Equivalent: --lowDefault model: claude-haiku-4-5Use for:
  • Quick tests
  • Simple tasks
  • Cost-sensitive workloads
  • High-volume automation
--low
flag
Alias for --haiku
ai --low task.md

Custom Model Selection

--model
flag
Specify exact model ID - Use any model supported by your provider
ai --model claude-opus-4-7
ai --aws --model global.anthropic.claude-opus-4-7
ai --ollama --model qwen3-coder
ai --vercel --model openai/gpt-5.2-codex
ai --codex --model gpt-5.4
Format depends on provider:
  • AWS Bedrock: global.anthropic.claude-opus-4-7
  • Vertex AI: claude-opus-4-7
  • Anthropic API: claude-opus-4-7
  • Ollama: Model name from ollama list
  • Vercel: provider/model-name (e.g., openai/gpt-4)
Precedence: --model overrides tier flags (--opus, --sonnet, --haiku)

Model Defaults Per Provider

Claude Subscription (Pro/Max)

ai --pro                 # Uses your subscription's latest model
Claude Pro/Max doesn’t support tier selection - it always uses the latest available model from your subscription.

API Providers (AWS, Vertex, Anthropic, Azure)

TierDefault Model
Opus (--opus, --high)claude-opus-4-7
Sonnet (--sonnet, --mid)claude-sonnet-4-6
Haiku (--haiku, --low)claude-haiku-4-5
Default tier: High (Opus)
ai --aws                 # Uses Opus
ai --aws --sonnet        # Uses Sonnet
ai --aws --haiku         # Uses Haiku

Local Providers (Ollama, LM Studio)

ai --ollama --model qwen3-coder          # Specify model name
ai --lmstudio --model mlx-qwen-32b       # Specify model name
Local providers don’t have default models - you must specify with --model or configure a default in ~/.ai-runner/secrets.sh.

Codex CLI

TierDefault Model
High (--opus, --high)gpt-5.4
Mid (--sonnet, --mid)gpt-5.3-codex
Low (--haiku, --low)gpt-5.4-mini
Default: gpt-5.4 (Codex native default). Tier flags override: --mid selects gpt-5.3-codex.
ai --codex                   # Uses gpt-5.4 (native default)
ai --codex --mid             # Uses gpt-5.3-codex
ai --codex --haiku           # Uses gpt-5.4-mini
Override in ~/.ai-runner/secrets.sh:
export CODEX_MODEL_HIGH="gpt-5.4"
export CODEX_MODEL_MID="gpt-5.3-codex"
export CODEX_MODEL_LOW="gpt-5.4-mini"

Vercel AI Gateway

ai --vercel --model openai/gpt-5.2-codex        # OpenAI
ai --vercel --model anthropic/claude-opus-4.7   # Anthropic
ai --vercel --model google/gemini-exp-2506      # Google
Vercel supports 100+ models. Use provider/model-name format. See Vercel AI Gateway docs for available models.

Configuration

View Default Models

ai-status    # Shows default model IDs for each tier

Override Model Defaults

Edit ~/.ai-runner/secrets.sh:
# Override AWS Sonnet model
export CLAUDE_MODEL_SONNET_AWS="global.anthropic.claude-sonnet-4-6"

# Override small/fast model (for background operations)
export CLAUDE_SMALL_FAST_MODEL_AWS="us.anthropic.claude-haiku-4-5-20251001-v1:0"

# Override Vertex Opus model
export CLAUDE_MODEL_OPUS_VERTEX="claude-opus-4-7"
See ~/.ai-runner/models.sh for all available override variables.

Dual Model Configuration

Claude Code uses two models:
  1. Primary model (ANTHROPIC_MODEL) - Interactive work, selected by tier flags
  2. Small/fast model (ANTHROPIC_SMALL_FAST_MODEL) - Background operations (defaults to Haiku)
When you run:
ai --aws --opus
  • Primary: Opus (claude-opus-4-7)
  • Background: Haiku (claude-haiku-4-5)
Both models show in ai-status output.

Examples

Tier Selection

# Most capable (Opus)
ai --aws --opus complex-refactor.md

# Balanced (Sonnet, default)
ai --aws task.md
ai --aws --sonnet task.md     # Explicit

# Fastest/cheapest (Haiku)
ai --aws --haiku quick-test.md

Custom Models

# Specific AWS Bedrock model
ai --aws --model us.anthropic.claude-opus-4-7

# Ollama local model
ai --ollama --model qwen3-coder

# Ollama cloud model (no GPU needed)
ai --ollama --model minimax-m2.5:cloud

# Vercel with OpenAI
ai --vercel --model openai/gpt-5.2-codex

# Vercel with xAI Grok
ai --vercel --model xai/grok-2

Shebang Scripts

#!/usr/bin/env -S ai --aws --opus
Complex task requiring the most capable model.
#!/usr/bin/env -S ai --ollama --model qwen3-coder
Local execution with specific model.

Resume with Different Model

# Start with Sonnet
ai --aws --sonnet

# Resume with Opus for complex reasoning
ai --aws --opus --resume

# Resume with Haiku for speed
ai --aws --haiku --resume

Cost Optimization

# Use Haiku for bulk operations
for file in *.md; do
  ai --aws --haiku --skip "$file" >> results.txt
done

# Use Opus only for critical review
ai --aws --opus --skip final-review.md

Model Recommendations

Task TypeRecommended TierReason
Complex refactoringOpusNeeds deep understanding
Architectural designOpusHigh-stakes decisions
Security analysisOpusAccuracy critical
General codingSonnetBalanced performance
DocumentationSonnetGood quality/speed ratio
Code reviewSonnetSufficient capability
Quick testsHaikuSpeed matters
Bulk automationHaikuCost-effective
Simple tasksHaikuOverhead not needed

Troubleshooting

Model IDs are provider-specific. Check your provider’s available models:
# AWS Bedrock
aws bedrock list-foundation-models --region us-west-2

# Ollama
ollama list

# Vertex AI
gcloud ai models list --region=us-central1
See provider documentation for correct model ID format.
Check for overrides in ~/.ai-runner/secrets.sh:
grep CLAUDE_MODEL ~/.ai-runner/secrets.sh
Verify active model in session:
ai-status
Tier flags work differently with local and Codex providers. For Ollama/LM Studio, you may need --model to specify a local model name. For Codex, tiers map to GPT models automatically.
ai --ollama --model qwen3-coder

Provider Flags

Switch between cloud providers

Provider Model Lists

Available models per provider