OpenRouter Pricing Basics Skill

OpenRouter Pricing Basics

Overview

OpenRouter charges per token with separate rates for prompt (input) and completion (output) tokens. Prices are listed per token in the models API (multiply by 1M for per-million rates). Credits are prepaid with a 5.5% processing fee ($0.80 minimum). Free models are available for testing and low-volume use.

How Pricing Works

Buy credits at openrouter.ai/credits (5.5% fee, $0.80 minimum)
Each request deducts (prompt_tokens * prompt_rate) + (completion_tokens * completion_rate)
Check balance via GET /api/v1/auth/key or the dashboard
Auto-topup is available to prevent service interruption

Query Model Pricing

# Get pricing for all models
curl -s https://openrouter.ai/api/v1/models | jq '.data[] | select(.id == "anthropic/claude-3.5-sonnet") | {
  id: .id,
  prompt_per_M: ((.pricing.prompt | tonumber) * 1000000),
  completion_per_M: ((.pricing.completion | tonumber) * 1000000),
  context: .context_length
}'
# → { "id": "anthropic/claude-3.5-sonnet", "prompt_per_M": 3, "completion_per_M": 15, "context": 200000 }

Cost Tiers (Representative)

| Tier | Example Model | Prompt/1M | Completion/1M | Use Case | |------|--------------|-----------|---------------|----------| | Free | google/gemma-2-9b-it:free | $0.00 | $0.00 | Testing, prototyping | | Budget | meta-llama/llama-3.1-8b-instruct | $0.06 | $0.06 | Simple Q&A, classification | | Mid | openai/gpt-4o-mini | $0.15 | $0.60 | General purpose | | Standard | anthropic/claude-3.5-sonnet | $3.00 | $15.00 | Complex reasoning, code | | Premium | openai/o1 | $15.00 | $60.00 | Deep reasoning |

Calculate Request Cost

def estimate_cost(model_id: str, prompt_tokens: int, completion_tokens: int) -> float:
    """Calculate cost for a single request."""
    import requests
    models = requests.get("https://openrouter.ai/api/v1/models").json()["data"]
    model = next((m for m in models if m["id"] == model_id), None)
    if not model:
        raise ValueError(f"Model {model_id} not found")

    prompt_rate = float(model["pricing"]["prompt"])       # Cost per token
    completion_rate = float(model["pricing"]["completion"])
    return (prompt_tokens * prompt_rate) + (completion_tokens * completion_rate)

# Example: Claude 3.5 Sonnet, 1000 prompt + 500 completion tokens
cost = estimate_cost("anthropic/claude-3.5-sonnet", 1000, 500)
print(f"Estimated cost: ${cost:.6f}")  # ~$0.0105

Track Actual Cost Per Request

import requests

# Method 1: From response usage (estimate)
response = client.chat.completions.create(
    model="anthropic/claude-3.5-sonnet",
    messages=[{"role": "user", "content": "Hello"}],
    max_tokens=100,
)
# response.usage.prompt_tokens, response.usage.completion_tokens

# Method 2: Query generation endpoint (exact cost from OpenRouter)
gen = requests.get(
    f"https://openrouter.ai/api/v1/generation?id={response.id}",
    headers={"Authorization": f"Bearer {os.environ['OPENROUTER_API_KEY']}"},
).json()
print(f"Exact cost: ${gen['data']['total_cost']}")
print(f"Tokens: {gen['data']['tokens_prompt']} prompt + {gen['data']['tokens_completion']} completion")

Check Credit Balance

curl -s https://openrouter.ai/api/v1/auth/key \
  -H "Authorization: Bearer $OPENROUTER_API_KEY" | jq '{
    credits_used: .data.usage,
    credit_limit: .data.limit,
    remaining: ((.data.limit // 0) - .data.usage),
    is_free_tier: .data.is_free_tier
  }'

Save Money with Variants

# :floor variant picks the cheapest provider for a model
response = client.chat.completions.create(
    model="anthropic/claude-3.5-sonnet:floor",  # Cheapest provider
    messages=[{"role": "user", "content": "Hello"}],
    max_tokens=100,
)

# :free variant uses free providers (where available)
response = client.chat.completions.create(
    model="google/gemma-2-9b-it:free",
    messages=[{"role": "user", "content": "Hello"}],
    max_tokens=100,
)

Special Pricing

| Item | Pricing | |------|---------| | Reasoning tokens | Charged as output tokens at completion rate | | Image inputs | Per-image charge listed in pricing.image | | Per-request fee | Some models charge a flat fee per request (pricing.request) | | BYOK | First 1M requests/month free; then 5% of normal provider cost | | Free model limits | 50 req/day (free users), 1000 req/day (with $10+ credits) |

Error Handling

| HTTP | Cause | Fix | |------|-------|-----| | 402 | Insufficient credits | Top up at openrouter.ai/credits or use :free model | | 402 | Key credit limit reached | Increase key limit or use a different key |

Enterprise Considerations

Set per-key credit limits via the dashboard or provisioning API to isolate blast radius
Query /api/v1/generation?id= after each request for exact cost auditing
Use :floor variant to automatically pick the cheapest provider
Route simple tasks to budget models and complex tasks to premium models (see openrouter-model-routing)
Set max_tokens on every request to cap completion cost
Enable auto-topup to prevent service interruptions in production

References

Examples | Errors
Pricing | Credits | Models API

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