Eonebill API Reference
Understand what the integration API exposes before handing the contract to Zapier, an AI agent, or another developer tool.
OpenAPI
3.1.0
Contract version
1.0.0
Public paths
76
Operations
101
Delivery boundary
What is ready now
The API contract, scoped key management, monthly usage enforcement, and discovery files are available for private integration testing. Zapier directory publishing and public MCP access remain separate releases.
OpenAPI contract
A validated OpenAPI 3.1 document describes public routes, methods, schemas, responses, and authentication.
Discovery catalog
A well-known API catalog lets compatible tools locate the contract without a hard-coded file path.
Agent-ready foundation
The same contract can ground future Zapier actions and MCP tools while keeping implementation details private.
Authentication is explicit
Every operation declares whether it accepts an organization API key, OAuth 2.1 access token, or signed-in Bearer session. Sensitive human actions such as sending an invoice remain session-only.
API key
Authorization: Bearer eob_...
Intended for supported machine-to-machine operations scoped to an organization.
Manage API keysOAuth 2.1
Authorization: Bearer <oauth-token>
Authorization code + PKCE for third-party apps, with explicit organization and scope consent.
Register OAuth appBearer session
Authorization: Bearer <session>
Required for user-authorized actions and endpoints not enabled for API keys.
Predictable monthly limits
Every organization receives 1,000 API-key requests per UTC month. Multiple keys share the same allowance, so creating a new key does not reset usage.
Monthly allowance
1,000
API-key requests per organization
Hard limit
HTTP 429
No silent expansion beyond the allowance
Reset window
UTC month
Retry-After identifies the next available time
X-RateLimit-Limit, X-RateLimit-Remaining, and X-RateLimit-Reset. A limited response also includes Retry-After.Core workflow
Invoice and customer endpoints
Authentication badges below are read from the generated contract, not maintained separately.
List invoices
/api/v1/invoicesCreate an invoice
/api/v1/invoicesRetrieve an invoice
/api/v1/invoices/{id}Update an invoice
/api/v1/invoices/{id}Send an invoice
/api/v1/invoices/{id}/sendSend a payment reminder
/api/v1/invoices/{id}/remindList customers
/api/v1/customersCreate a customer
/api/v1/customersCoverage by module
The largest public API areas in the current generated contract.
Source of truth
Use the files when you are ready to integrate
The JSON document is for tools and code generators. The catalog is the stable discovery entry point. This page is the human acceptance view of the same delivery.