BILL website screenshot

BILL

BILL (formerly Bill.com) is a cloud-based financial operations platform for small and midsize businesses that automates accounts payable, accounts receivable, and spend & expense management. The BILL API Platform exposes these workflows through the BILL v3 REST API and embeddable BILL Elements UI components, enabling partners and ERPs to integrate bill capture, approvals, payments, and real-time event notifications via webhooks. The API uses session-based authentication with API keys and developer keys against production and sandbox gateways.

BILL publishes 10 APIs on the APIs.io network, including v3 API, Authentication API, Bills API, and 7 more. Tagged areas include Accounts Payable, Accounts Receivable, Spend Management, Expense Management, and Payments.

The BILL catalog on APIs.io includes 1 event-driven AsyncAPI specification and 1 Spectral governance ruleset.

BILL’s developer surface includes authentication, documentation, API reference, pricing, signup flow, support, and 6 more developer resources.

🌐 Visit website 📡 Source on GitHub
35.2/100 thin ▬ flat Agent 33/100 agent aware Full breakdown ↓
scored 2026-07-28 · rubric v0.6
AccessSelf serve
11 APIs
Accounts PayableAccounts ReceivableSpend ManagementExpense ManagementPaymentsBill PayFinancial OperationsFintech

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-28 · rubric v0.6
Composite quality — 35.2/100 · thin
Contract Quality 15.9 / 25
Developer Ergonomics 7.8 / 20
Commercial Clarity 2.1 / 20
Operational Transparency 0.0 / 13
Governance 5.7 / 12
Discoverability 6.5 / 10
Agent readiness — 33/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 0 / 7
Typed Event Surface 6 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/bill: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 11

Individual APIs this provider publishes, each with its own machine-readable definition.

BILL v3 API

REST API providing full-breadth access to BILL's Accounts Payable, Accounts Receivable, and Spend & Expense capabilities including bills, invoices, vendors, customers, payments,...

BILL Elements

Low-code, embeddable UI components that surface the BILL Accounts Payable workflow inside partner applications with minimal development effort.

BILL Authentication API

The Authentication API from BILL — 5 operation(s) for authentication.

BILL Bills API

The Bills API from BILL — 4 operation(s) for bills.

BILL Customers API

The Customers API from BILL — 3 operation(s) for customers.

BILL Funding Accounts API

The Funding Accounts API from BILL — 2 operation(s) for funding accounts.

BILL Invoices API

The Invoices API from BILL — 3 operation(s) for invoices.

BILL Organizations API

The Organizations API from BILL — 2 operation(s) for organizations.

BILL Payments API

The Payments API from BILL — 5 operation(s) for payments.

BILL Vendors API

The Vendors API from BILL — 3 operation(s) for vendors.

BILL Webhooks API

The Webhooks API from BILL — 2 operation(s) for webhooks.

Scroll for all 11

Open Collections 1

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

BILL v3 API

OPEN COLLECTION

Event Specifications 1

AsyncAPI definitions for this provider's event-driven and streaming APIs.

BILL Webhooks

Outbound webhook event notifications delivered by the BILL v3 API Platform to subscriber `notificationUrl` endpoints. Subscribers register through the BILL v3 webhook subscripti...

ASYNCAPI

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

BILL API Rules

8 rules · 1 errors 6 warnings 1 info

SPECTRAL

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Bill Authentication

apiKey · 1 scheme

SECURITY

Bill Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Bill Agentic Access

40 operations · 26 acting

40 operations · 26 acting

AGENTIC

Resources

Get Started 2

Portal, sign-up, and the first successful call

DeveloperPortal
DeveloperPortal
 Signup
Signup

Documentation 2

Reference material describing how the API behaves

Documentation
Documentation
 APIReference
APIReference

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess
AgenticAccess
 LlmsText
LlmsText

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity
 Authentication
Authentication

Operate 1

Status, limits, changes, and where to get help

Support
Support

Commercial 1

Pricing, plans, and the legal terms of use

Pricing
Pricing

Company 2

The organization behind the API

Website
Website
 LinkedIn
LinkedIn

Source (apis.yml)

apis.yml Raw ↑ 
aid: bill
name: BILL
description: BILL (formerly Bill.com) is a cloud-based financial operations platform for small and midsize businesses that
  automates accounts payable, accounts receivable, and spend & expense management. The BILL API Platform exposes these workflows
  through the BILL v3 REST API and embeddable BILL Elements UI components, enabling partners and ERPs to integrate bill capture,
  approvals, payments, and real-time event notifications via webhooks. The API uses session-based authentication with API
  keys and developer keys against production and sandbox gateways.
type: Index
accessModel:
  pricing: unknown
  onboarding: self-serve
  trial: false
  try_now: false
  public: false
  label: Self-serve signup
  confidence: medium
  source:
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/bill.png
tags:
- Accounts Payable
- Accounts Receivable
- Spend Management
- Expense Management
- Payments
- Bill Pay
- Financial Operations
- Fintech
url: https://raw.githubusercontent.com/api-evangelist/bill/refs/heads/main/apis.yml
created: '2026-05-11'
modified: '2026-05-30'
specificationVersion: '0.19'
apis:
- aid: bill:v3-api
  name: BILL v3 API
  description: REST API providing full-breadth access to BILL's Accounts Payable, Accounts Receivable, and Spend & Expense
    capabilities including bills, invoices, vendors, customers, payments, approvals, and webhook event notifications. Production
    calls are made to https://gateway.prod.bill.com/connect/v3 with sandbox at https://gateway.stage.bill.com/connect/v3.
  humanURL: https://developer.bill.com/docs/bill-v3-api-get-started
  baseURL: https://gateway.prod.bill.com/connect/v3
  tags:
  - Accounts Payable
  - Accounts Receivable
  - Spend Management
  - Payments
  - Webhooks
  properties:
  - type: Documentation
    url: https://developer.bill.com/docs/home
  - type: APIReference
    url: https://developer.bill.com/reference
  - type: GettingStarted
    url: https://developer.bill.com/docs/bill-v3-api-get-started
  - type: Postman
    url: https://www.postman.com/bill-api-platform/bill-api-platform-workspace/overview
  - type: AsyncAPI
    url: https://raw.githubusercontent.com/api-evangelist/bill/refs/heads/main/asyncapi/bill-webhooks-asyncapi.yml
- aid: bill:elements
  name: BILL Elements
  description: Low-code, embeddable UI components that surface the BILL Accounts Payable workflow inside partner applications
    with minimal development effort.
  humanURL: https://developer.bill.com/docs/home
  tags:
  - Embeddable UI
  - Accounts Payable
  properties:
  - type: Documentation
    url: https://developer.bill.com/docs/home
- aid: bill:bill-authentication-api
  name: BILL Authentication API
  description: The Authentication API from BILL — 5 operation(s) for authentication.
  humanURL: https://developer.bill.com/docs/bill-v3-api-get-started
  baseURL: https://gateway.prod.bill.com/connect/v3
  tags:
  - Authentication
  properties:
  - type: OpenAPI
    url: openapi/bill-authentication-api-openapi.yml
- aid: bill:bill-bills-api
  name: BILL Bills API
  description: The Bills API from BILL — 4 operation(s) for bills.
  humanURL: https://developer.bill.com/docs/bill-v3-api-get-started
  baseURL: https://gateway.prod.bill.com/connect/v3
  tags:
  - Bills
  properties:
  - type: OpenAPI
    url: openapi/bill-bills-api-openapi.yml
- aid: bill:bill-customers-api
  name: BILL Customers API
  description: The Customers API from BILL — 3 operation(s) for customers.
  humanURL: https://developer.bill.com/docs/bill-v3-api-get-started
  baseURL: https://gateway.prod.bill.com/connect/v3
  tags:
  - Customers
  properties:
  - type: OpenAPI
    url: openapi/bill-customers-api-openapi.yml
- aid: bill:bill-funding-accounts-api
  name: BILL Funding Accounts API
  description: The Funding Accounts API from BILL — 2 operation(s) for funding accounts.
  humanURL: https://developer.bill.com/docs/bill-v3-api-get-started
  baseURL: https://gateway.prod.bill.com/connect/v3
  tags:
  - Funding Accounts
  properties:
  - type: OpenAPI
    url: openapi/bill-funding-accounts-api-openapi.yml
- aid: bill:bill-invoices-api
  name: BILL Invoices API
  description: The Invoices API from BILL — 3 operation(s) for invoices.
  humanURL: https://developer.bill.com/docs/bill-v3-api-get-started
  baseURL: https://gateway.prod.bill.com/connect/v3
  tags:
  - Invoices
  properties:
  - type: OpenAPI
    url: openapi/bill-invoices-api-openapi.yml
- aid: bill:bill-organizations-api
  name: BILL Organizations API
  description: The Organizations API from BILL — 2 operation(s) for organizations.
  humanURL: https://developer.bill.com/docs/bill-v3-api-get-started
  baseURL: https://gateway.prod.bill.com/connect/v3
  tags:
  - Organizations
  properties:
  - type: OpenAPI
    url: openapi/bill-organizations-api-openapi.yml
- aid: bill:bill-payments-api
  name: BILL Payments API
  description: The Payments API from BILL — 5 operation(s) for payments.
  humanURL: https://developer.bill.com/docs/bill-v3-api-get-started
  baseURL: https://gateway.prod.bill.com/connect/v3
  tags:
  - Payments
  properties:
  - type: OpenAPI
    url: openapi/bill-payments-api-openapi.yml
- aid: bill:bill-vendors-api
  name: BILL Vendors API
  description: The Vendors API from BILL — 3 operation(s) for vendors.
  humanURL: https://developer.bill.com/docs/bill-v3-api-get-started
  baseURL: https://gateway.prod.bill.com/connect/v3
  tags:
  - Vendors
  properties:
  - type: OpenAPI
    url: openapi/bill-vendors-api-openapi.yml
- aid: bill:bill-webhooks-api
  name: BILL Webhooks API
  description: The Webhooks API from BILL — 2 operation(s) for webhooks.
  humanURL: https://developer.bill.com/docs/bill-v3-api-get-started
  baseURL: https://gateway.prod.bill.com/connect/v3
  tags:
  - Webhooks
  properties:
  - type: OpenAPI
    url: openapi/bill-webhooks-api-openapi.yml
common:
- type: AgenticAccess
  url: agentic-access/bill-agentic-access.yml
- type: DomainSecurity
  url: security/bill-domain-security.yml
- type: Authentication
  url: authentication/bill-authentication.yml
- type: Website
  url: https://www.bill.com
- type: DeveloperPortal
  url: https://developer.bill.com
- type: Documentation
  url: https://developer.bill.com/docs/home
- type: APIReference
  url: https://developer.bill.com/reference
- type: Pricing
  url: https://www.bill.com/pricing
- type: Signup
  url: https://app.bill.com/Signup
- type: Support
  url: https://developersupport.bill.com
- type: LinkedIn
  url: https://www.linkedin.com/company/bill-com
- type: LlmsText
  url: https://developer.bill.com/llms.txt
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com