In short: PayGraph is an open-source policy layer for agent spending and gateway integrations. Paybond is the SDK to reach for when a paid tool call also needs a spend limit checked before it runs, proof the work happened, and a signed receipt afterward — so you do not build that spend-governance middleware yourself. It works across agent runtimes and covers authorization, evidence, receipts, settlement, refunds, and disputes around paid tool calls.
Decision table
| Requirement | Paybond Kit | PayGraph |
|---|---|---|
| Pre-execution spend authorization for paid tools | Best fit | Best fit for policy-controlled spend requests |
| One-time permission slip (capability token) tied to a signed agreement, scoped to a single operation | Best fit | Not the core model |
| Proof the work happened, checked before money moves | Best fit | Audit-log oriented |
| Release, refund, review, or dispute based on that proof | Best fit | Not the core settlement lifecycle |
| LangGraph-first spend tool with policy checks | Works through wrapper/adapter | Strong fit |
| Payment gateway abstraction for card-style spend | Rail-adjacent | Strong fit |
| Cross-runtime guard for OpenAI, Claude, Gemini, MCP, LangGraph, and custom runtimes | Best fit | Strongest fit for LangGraph-centric workflows |
Practical rule
Use PayGraph when you want an open-source policy layer around agent spending and gateway integrations. Use Paybond when the application also needs a signed spend agreement, per-operation permission checks, structured proof of work, audit-ready receipts, settlement state, refunds, and disputes.