AgentBill

Usage-based billing for AI agents. Preflight. Per-request ceiling. No Stripe.

Stripe tells you how much you spent. Too late. AgentBill blocks the run before it starts if the budget says so.

"The moment you're using Stripe as your safety net, you've already lost the run." — scarlett1908, r/LangChain

Install

pip install agentbill-sdk

Quick Start

from agentbill import AgentBillClient

client = AgentBillClient(api_key="agb_your_key")

check = client.preflight(agent_id="researcher", budget=5.00) if not check.approved: raise Exception("Budget exceeded")

client.record(agent_id="researcher", cost=check.estimated_cost)

Get your API key: https://agentbill.fly.dev/register

What it does

Preflight. Before the agent runs, AgentBill checks: does this customer have enough budget? If not, block it before any compute is consumed.

Per-request ceiling. Monthly caps do not catch the bad single run. One 3-hour research loop can blow your budget before the cap triggers. AgentBill enforces a ceiling at the invocation level.

Outcome-based metering. You define what counts as a billable event. Not bytes, not seconds. The business-level action the agent performed.

Free tier

1,000 preflight calls/month. No credit card required.

What it does NOT do

• Multi-step workflows with state machines or reversal logic (out of scope)

• Replace your payment processor (AgentBill sits in front of it)

• No-code dashboard for non-developers

Node.js

npm install agentbill

Why not Stripe

Stripe | AgentBill Preflight block: No | Yes Per-request ceiling: No | Yes Blocks before compute: No | Yes Built for agents: No | Yes

MCP Server

AgentBill ships an MCP server for native integration with Claude Code, Cursor, Windsurf, and any MCP-compatible agent host.

Install via agentbill-mcp on PyPI:

uvx agentbill-mcp

The MCP server exposes two tools:

• preflight(agent_id, customer_id, estimated_units, ceiling) — check budget before running. Blocks if exhausted.

• record_event(agent_id, units, customer_id, metadata) — bill after work completes.

Configure in ~/.claude/settings.json:

{
  "mcpServers": {
    "agentbill": {
      "command": "uvx",
      "args": ["agentbill-mcp"],
      "env": { "AGENTBILL_API_KEY": "sk_live_..." }
    }
  }
}

Source: mcp/ | PyPI: agentbill-mcp | MCP Registry: io.github.marketinglior-pixel/agentbill-mcp

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