Tariff

LLM Pricing Oracle — an MCP server that pulls real pricing data from the LiteLLM community registry and exposes it as tools any MCP client can query.

No API keys. No accounts. No configuration files.

Install

Claude Code:

claude mcp add tariff -- npx -y @atriumn/tariff

Cursor (.cursor/mcp.json):

{
  "mcpServers": {
    "tariff": {
      "command": "npx",
      "args": ["-y", "@atriumn/tariff"]
    }
  }
}

Tools

| Tool | Description | |------|-------------| | get_model_details | Look up pricing, context window, and capabilities for a model | | calculate_estimate | Estimate cost for a given token count | | compare_models | Filter and compare models by provider, context window, or mode | | refresh_prices | Force re-fetch pricing data from the registry |

Example

"How much does Claude Sonnet 4.5 cost per million tokens?"

Model: claude-sonnet-4-5
Provider: anthropic
Mode: chat

Pricing (per 1M tokens):
  Input:  $3.00
  Output: $15.00

Context Window:
  Max Input:  200K
  Max Output: 8K

Capabilities: vision, function_calling, parallel_function_calling

How it works

1. On first use, the server fetches pricing data from the LiteLLM community registry
2. Data is cached in-memory for 24 hours (with a disk fallback)
3. Your AI assistant calls tools via the MCP protocol
4. Results are returned as formatted text

No data leaves your machine — the only network request is fetching the public pricing registry.

Docs

Full documentation at tokencost.dev

License

MIT