API workflows

The following sections describe the API workflows used during onboarding, including decision flows, item classification, and address validation.

Onboarding API decision flow

This section explains how the onboarding workflow selects the appropriate API actions based on the current onboarding step and whether the configuration is new, existing, or mapped.

Table 1. API usage by onboarding step
Onboarding step	Primary APIs	Purpose
Step 2: Preflight	`QueryCompanies`, `ListNexusByCompany`	Detect existing AvaTax configuration to support intelligent mapping decisions.
Step 3: Company setup	`CreateCompanies`, `CompanyInitialize`	Create a new AvaTax company or map an existing company to an ERP entity.
Step 4: Nexus	`ResolveAddressPost`, `CreateNexus`	Validate addresses, extract jurisdiction information, and declare nexus.
Step 5: Items	`TaxCodeRecommendations`, `CreateItemClassifications`	Perform AI-assisted tax code classification with a selected storage destination.
Step 6: Customers	`CreateCustomers`, `CreateCertExpressInvitation`	Synchronize customers to ECMS and manage exemption certificate onboarding.

Execution model

Each onboarding step implements API calls immediately after user confirmation. Changes are applied when the user approves them. There’s no batch execution at the end of the onboarding process.

Item classification workflow

This section describes the API sequence used to classify ERP items and assign AvaTax tax codes during onboarding.

Item classification follows this workflow:

Bulk classification support

Currently, items are classified individually during onboarding. A bulk classification API is coming soon to support faster onboarding for large item catalogs.

Address validation and jurisdiction extraction

This section describes how address data is validated and converted into jurisdiction information used by nexus and customer-related workflows.

The ResolveAddressPost API is central to address validation and jurisdiction determination during onboarding and post onboarding workflows.

The API is used as follows:

Input: Raw address data sourced from ERP location records or customer records.
Validation: The address is standardized, corrected, and geocoded to ensure accuracy and consistency.
Jurisdiction extraction: The API returns jurisdiction identifiers, including:
- State
- County
- City
- Special districts
Nexus proposal support: The AI agent uses the extracted jurisdiction codes to evaluate physical presence and recommend appropriate nexus declarations.