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MCP agent spend controls

Authorize agent spend through paybond-mcp-server — tenant-bound MCP tools for coding agents, Claude Desktop, and stdio MCP hosts.

MCP hosts (Claude Desktop, Codex, Cursor, custom orchestrators) launch Paybond as a stdio MCP server. The server exposes a tenant-bound tool surface: verify capabilities, authorize spend before side-effecting work, and submit evidence — same tenant boundary as the SDKs.

MCP is a first-class adapter

MCP hosts are a supported integration path alongside in-process adapters. Coding agents often start here before wiring paybond.instrument() in application code.

Try it (sandbox MCP path)

Terminal
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paybond login
paybond agent sandbox smoke \
  --operation paid-tool \
  --requested-spend-cents 100 \
  --evidence-preset cost_and_completion \
  --result-body '{"status":"ok","cost_cents":100}' \
  --format table

For MCP-native sandbox tools inside a running host, call paybond_bootstrap_sandbox_guardrail before the paid tool and paybond_submit_sandbox_guardrail_evidence after.

Launch the server

terminal

Terminal commandSwipe to inspect long lines
npx -y -p @paybond/kit paybond-mcp-server

Required: PAYBOND_API_KEY (from paybond login → .env.local). Optional policy hot-reload:

Terminal
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export PAYBOND_POLICY_FILE="./paybond.policy.yaml"
export PAYBOND_POLICY_RELOAD="watch"

Claude Desktop / Codex config

Add to your MCP host config (stdio):

{
  "mcpServers": {
    "paybond": {
      "command": "npx",
      "args": ["-y", "-p", "@paybond/kit", "paybond-mcp-server"],
      "env": {
        "PAYBOND_ENV_FILE": ".env.local"
      }
    }
  }
}

Full coding-agent setup: /docs/kit/coding-agent-setup.

Production MCP flow

  1. paybond_create_spend_intent or paybond_fund_intent → intent_id + capability_token
  2. paybond_authorize_agent_spend before the paid or side-effecting tool
  3. Execute vendor work
  4. paybond_submit_spend_evidence with completion payload

PAYBOND_MCP_EVIDENCE_POLICY defaults to strict — evidence submit tools refuse calls until validation succeeds for the preset and payload.

Scaffold a paid-tool guard

Terminal
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npx -p @paybond/kit paybond-init \
  --preset paid-tool-guard \
  --framework provider-agnostic \
  --out paybond-paid-tool-guard.ts

For multi-tool agents in application code, graduate to agent middleware.

Developer reference: /docs/kit/mcp-server.