Fastbill

Live 57 Actions 11 Events

Fastbill Integration for AI Agents

Connect your AI agent to 57 Fastbill actions via MCP, A2A, or SDK, with agent authentication, tool-calling execution, and security built-in, plus 11 events to subscribe to.

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Fastbill AI Agent Actions

57 production-ready actions for your agent to do more on Fastbill.

Read the Fastbill docs

57 Actions

List Customers - Retrieve a list of customers from Fastbill with optional filtering.

Get Customer - Retrieve a specific customer by ID from Fastbill.

Create Customer - Create a new customer in Fastbill.

Update Customer - Update an existing customer in Fastbill.

Delete Customer - Delete a customer from Fastbill.

List Contacts - Retrieve contacts for customers from Fastbill.

Create Contact - Create a new contact for a customer in Fastbill.

Update Contact - Update an existing contact in Fastbill.

Delete Contact - Delete a contact from Fastbill.

List Invoices - Retrieve a list of invoices from Fastbill with optional filtering.

Get Invoice - Retrieve a specific invoice by ID from Fastbill.

Create Invoice - Create a new invoice draft in Fastbill.

Update Invoice - Update an existing invoice draft in Fastbill.

Delete Invoice - Delete an invoice draft from Fastbill.

Complete Invoice - Finalize an invoice draft and convert it to a completed invoice.

Cancel Invoice - Cancel a completed invoice in Fastbill.

Lock Invoice - Finalize an invoice in Fastbill.

Set Invoice Paid - Mark an invoice as paid in Fastbill.

Send Invoice By Email - Send a completed invoice to a recipient via email with PDF attachment.

Send Invoice By Post - Send a completed invoice via postal mail.

List Estimates - Retrieve a list of estimates/quotes from Fastbill with optional filtering.

Get Estimate - Retrieve a specific estimate by ID from Fastbill.

Create Estimate - Create a new estimate/quote in Fastbill.

Delete Estimate - Delete an estimate from Fastbill.

Send Estimate By Email - Send an estimate to a recipient via email with PDF attachment.

Convert Estimate To Invoice - Convert an existing estimate into an invoice.

List Recurring Invoices - Retrieve a list of recurring invoices from Fastbill.

Get Recurring Invoice - Retrieve a specific recurring invoice by ID from Fastbill.

Create Recurring Invoice - Create a new recurring invoice in Fastbill.

Update Recurring Invoice - Update an existing recurring invoice in Fastbill.

Delete Recurring Invoice - Delete a recurring invoice from Fastbill.

List Revenues - Retrieve a list of revenue entries from Fastbill with optional filtering.

Get Revenue - Retrieve a specific revenue entry by ID from Fastbill.

Create Revenue - Create a new revenue entry in Fastbill.

Set Revenue Paid - Mark a revenue entry as paid in Fastbill.

Delete Revenue - Delete a revenue entry from Fastbill.

List Expenses - Retrieve a list of expense entries from Fastbill with optional filtering.

Get Expense - Retrieve a specific expense entry by ID from Fastbill.

Create Expense - Create a new expense entry in Fastbill.

List Articles - Retrieve a list of products/articles from Fastbill.

Get Article - Retrieve a specific product/article by ID from Fastbill.

Create Article - Create a new product/article in Fastbill.

Update Article - Update an existing product/article in Fastbill.

Delete Article - Delete a product/article from Fastbill.

List Projects - Retrieve a list of projects from Fastbill with optional filtering.

Get Project - Retrieve a specific project by ID from Fastbill.

Create Project - Create a new project in Fastbill.

Update Project - Update an existing project in Fastbill.

Delete Project - Delete a project from Fastbill.

List Time Entries - Retrieve a list of time tracking entries from Fastbill with optional filtering.

Get Time Entry - Retrieve a specific time entry by ID from Fastbill.

Create Time Entry - Create a new time tracking entry in Fastbill.

Update Time Entry - Update an existing time entry in Fastbill.

Delete Time Entry - Delete a time entry from Fastbill.

List Templates - Retrieve a list of invoice/estimate templates from Fastbill.

List Documents - Retrieve a list of documents and folders from Fastbill.

Create Document - Create a document entry in the Fastbill inbox.

Fastbill Webhook Events

11 real-time Fastbill events your AI agent can subscribe to.

Webhooks for AI agents Read the Fastbill docs

11 Events

Customer Created Webhook Processes Fastbill customer.created events.
Customer Updated Webhook Processes Fastbill customer.updated events.
Customer Deleted Webhook Processes Fastbill customer.deleted events.
Contact Created Webhook Processes Fastbill contact.created events.
Contact Updated Webhook Processes Fastbill contact.updated events.
Contact Deleted Webhook Processes Fastbill contact.deleted events.
Invoice Created Webhook Processes Fastbill invoice.created events.
Invoice Completed Webhook Processes Fastbill invoice.completed events.
Invoice Canceled Webhook Processes Fastbill invoice.canceled events.
Estimate Created Webhook Processes Fastbill estimate.created events.
Estimate Updated Webhook Processes Fastbill estimate.updated events.

Fastbill AI Agent Use Cases

Connect your AI agent to Fastbill and help your team scale the finance operations they run by hand today.

Invoice Processing

Automate invoice processing with AI agents connected to your ERP, accounting software, and AP tools through StackOne.

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Accounts Receivable Dunning

Use StackOne to connect your AI agent to your accounting, CRM, and messaging systems to automate Accounts Receivable dunning and payment follow-up.

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Invoice Processing

Use StackOne to connect your AI agent to your accounting, email, and document management systems to automate invoice processing and purchase order matching.

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More Accounting & Finance use cases

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Integration Infrastructure for Fastbill AI Agents

Multiple Interfaces

Access integrations via API, AI SDKs, MCP & A2A.

Fastbill MCP server

Managed Authentication

Pre-built authentication UI.

Agent auth

Falcon Engine

Every Fastbill action runs on Falcon.

Agent Execution Engine

StackOne Defender

88.7% prompt injection detection.

Prompt injection defense

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"What impressed us most about StackOne is its ambition and clarity. They're creating infrastructure that modern software and the entire AI agent ecosystem can rely on. The depth of secure integrations, the pace of delivery, and the team's foresight into AI's future uniquely position StackOne to redefine this category."

Luna Schmid, Partner at GV

"We've been impressed by how quickly and deeply StackOne integrates with complex enterprise systems -- and now, with their focus on agent-to-agent interoperability, they're unlocking even more powerful use cases for customers. StackOne delivers all of the above in a universal layer -- without compromise."