Paybond Kit
Add paid-tool guardrails before you wire settlement.
Start with one sandbox guardrail scaffold, then use Paybond Kit across MCP hosts, LangGraph apps, OpenAI, Claude/Anthropic, Gemini, and custom runtimes for delegated spend authorization, budget checks, evidence, receipts, settlement, refunds, and disputes.
What Kit adds to your runtime
The SDK covers the application path around settlement so product teams do not have to rebuild it inside every agent workflow.
Start from one tenant
Open an SDK session from service-account credentials and keep each workflow tied to the right workspace.
Check before work runs
Authorize the paid tool call, operation name, and requested spend before a side-effecting action executes.
Submit proof once
Send structured evidence through the same client so release, refund, disputes, and exports all point at the same record.
Keep rails configured server-side
Request a supported settlement rail by name while payout destinations remain owned by tenant configuration.
Supported paths, without guessing
Kit is the public SDK surface for product teams integrating Paybond. The support matrix documents the current languages, agent framework patterns, and settlement rails.
TypeScript
@paybond/kit for modern Node.js runtimes, with quickstarts and example projects for backend integrations.
Python
paybond-kit for Python 3.11+, including published wheels with the native signing extension.
Agent frameworks
Wrappers for OpenAI, Gemini, Claude/Anthropic, local models, LangGraph, MCP hosts, CrewAI-style tools, and custom runtimes.
MCP and LangGraph
Use paybond-mcp-server for MCP-compatible hosts, or the LangGraph integration hooks when a graph node needs a spend check before a paid tool runs.
Settlement rails
Stripe Connect, Stripe ACH Direct Debit, and x402/USDC on Base are the supported public rails today.
What Kit covers
Kit covers application flows
Use it for sessions, signed spend intents, spend authorization, allowed-action checks, evidence submission, selected protocol helpers, and read-only Signal data.
Operators still confirm settlement
Release and refund confirmation remains an operator-reviewed workflow in the console, or a direct API call if your rollout is designed that way.
Start from the right guide
How a Kit-backed workflow runs
From agreement setup to evidence submission, the SDK keeps the settlement steps close to the workflow that needs them.
Step 1
Open an SDK session
Start with service-account credentials issued for one tenant and environment.
Step 2
Create an agreement
Define the counterparty, budget, completion rule, evidence shape, allowed operations, and settlement rail.
Step 3
Check the action
Before the workflow calls a paid tool or spends budget, verify the requested operation and amount against the agreement.
Step 4
Perform the work
Your agent or application runs in the runtime you already operate.
Step 5
Submit evidence
Attach the signed result payload and artifacts that prove what happened.
Step 6
Review the outcome
Paybond records the settlement state and makes receipts, exports, and review records available downstream.
Kit keeps settlement guarantees in the integration path.
Application code should not have to recreate spend-governance middleware from scratch. Kit keeps the important boundaries visible where workflows run.
Guarantees
- Tenant scope comes from authenticated credentials.
- Approved operations are checked before work executes.
- Rails are requested by name; destinations remain in tenant settlement config.
- Evidence stays structured for review, exports, and disputes.
Designed for agent runtimes
Use Kit where workflows already run: orchestrators, tool routers, sandboxes, and multi-tenant application backends.
Agent orchestrators
Add spend authorization and settlement checks around tool calls without replacing the planning or execution engine.
Tool routers and sandboxes
Gate side-effecting actions with approved operation names from your own application namespace.
Multi-tenant platforms
Keep each customer workspace tied to its own credentials, settlement configuration, and evidence records.
Kit FAQ
Language support, framework fit, supported rails, and current SDK boundaries.
Do I have to use Kit to use Paybond?
No. You can integrate directly with the APIs, but Kit is the supported SDK path for sessions, agreements, allowed-action checks, evidence submission, and common reads.
Which languages are supported?
Kit supports TypeScript on modern Node.js runtimes and Python 3.11+. The support matrix lists current SDKs, framework integrations, and rails.
Do I need a specific agent framework?
No. Kit works as SDK primitives you can wrap around your own workflow. The docs include patterns that work across runtimes, plus OpenAI, Gemini, Claude/Anthropic, LangGraph, MCP, and custom-tool integration paths.
Does Paybond support MCP and LangGraph?
Yes. Paybond Kit includes a tenant-bound MCP server for MCP-compatible hosts and LangGraph integration hooks for graph workflows that need spend authorization before paid tools run.
How does Kit relate to Harbor?
Kit is the application-facing SDK. Harbor is the Paybond settlement service behind the agreement, evidence, and release/refund lifecycle.
Which settlement rails can Kit request?
Kit can request Stripe Connect, Stripe ACH Direct Debit, or x402/USDC on Base. Amounts remain USD-denominated; tenant-owned settlement configuration controls destinations.
What is not wrapped by Kit today?
Operator settlement confirmation is not wrapped. Use the Paybond console, or call the API directly if your rollout explicitly owns that workflow.