metrify-sdk 0.2.3

Billing SDK for MCP servers

metrify-sdk

Billing infrastructure for MCP servers. Add one decorator. Start charging. Get paid in USDT.

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Installation

pip install metrify-sdk

Requires Python 3.8+

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Quickstart (Provider)

Step 1 — Register at metrify.dev and get your pk_live_... provider key.

Step 2 — Install the SDK:

pip install metrify-sdk

Step 3 — Decorate your tools:

from metrify import Metrify
from mcp.server.fastmcp import FastMCP

mcp = FastMCP("my-mcp-server")
m = Metrify(provider_key="your_provider_key")

@mcp.tool()
@m.tool(price=0.01, description="Search the web for a query")
def search(query: str) -> str:
    # Your logic here
    return f"Results for: {query}"

if __name__ == "__main__":
    mcp.run(transport="streamable-http")

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How billing works

When a consumer calls your tool, Metrify verifies their balance before execution. If sufficient, the tool runs. On success, the consumer wallet is debited atomically: 95% goes to you, 5% to Metrify. If your tool raises an exception, the consumer is not charged.

Consumer wallet → [Metrify] → Provider wallet
    $0.01000           ↓          $0.00950
                  fee: $0.00050

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@m.tool() parameters

Parameter	Type	Required	Description
price	float	✓	Cost per call in USDT
description	str	✓	Tool description shown to agents

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Policy: no charge on upstream error

If your tool raises any exception, the consumer is not charged. Raise UpstreamError explicitly when an external API you depend on fails:

from metrify import Metrify, UpstreamError

m = Metrify(provider_key="your_provider_key")

@m.tool(price=0.05, description="Summarize text using an LLM")
async def summarize(text: str) -> str:
    try:
        result = await llm_client.complete(text)
    except Exception as e:
        raise UpstreamError(f"LLM unavailable: {e}")
    return result

The consumer receives your error message and is not charged. Idempotency keys are implemented from day one — duplicate charges are impossible.

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Provider registration

metrify.dev — currently invite-only waitlist.

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Links

• metrify.dev
• metrify-mcp — consumer wallet management MCP server
• Changelog

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License

MIT