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Available tools
resolve_address
Validate and geocode a US or Canadian address, returning AvaTax-normalized address candidates and the tax jurisdictions that apply to it. Useful before create_transaction to confirm an address resolves cleanly.
list_certificates
List a company's exemption certificates, with optional $filter and pagination.
get_certificate
Retrieve a single exemption certificate by ID. Use list_certificates to find valid IDs.
create_certificate
Create a new exemption certificate for a company. Use discoverexemptionreasons for exemptionreasonid, and discoverentityusecodes if the exemption is tied to a customer usage type. Requires the company be provisioned for exemption certificates first — use getcertificatesetup, and requestcertificate_setup if status is 'NotProvisioned'.
update_certificate
Update an existing exemption certificate. Only provided fields are changed.
delete_certificate
Revoke and delete an exemption certificate. This cannot be undone.
discover_entity_use_codes
List Avalara's supported entity use codes (customer/usage types for tax exemptions). Use this to find valid entityUseCode values for createtransaction line items and createcertificate.
discover_exemption_reasons
List Avalara's supported certificate exemption reasons. Use this to find the exemptionreasonid required by create_certificate.
get_certificate_setup
Check whether a company is provisioned for AvaTax's exemption certificate module (CertCapture). createcustomer and createcertificate fail until this returns status='Provisioned' — if it returns 'NotProvisioned', call requestcertificatesetup first.
request_certificate_setup
Provision a company for AvaTax's exemption certificate module (CertCapture). Required once per company before createcustomer or createcertificate will work. Use getcertificatesetup to check status; provisioning can take a few minutes to complete after this call.
list_companies
List companies on this Avalara account, with optional $filter/$orderBy and pagination. Use to find a company's internal id/companyCode before calling getcompany, createnexus, createitem, createtransaction, etc.
get_company
Retrieve a single Avalara company by internal ID. Use list_companies to find valid IDs.
create_company
Create a new company on this Avalara account. companyCode must be unique on the account.
update_company
Update an existing Avalara company. Only provided fields are changed. Use get_company to check current values first.
delete_company
Delete a company from this Avalara account. This cannot be undone. Use get_company to verify the record first.
list_customers
List a company's customers, with optional $filter/$orderBy and pagination.
get_customer
Retrieve a single customer by customer code. Use list_customers to find valid codes.
create_customer
Create a new customer record for a company. customerCode must be unique within the company. Requires the company be provisioned for exemption certificates first — use getcertificatesetup, and requestcertificatesetup if status is 'NotProvisioned'.
update_customer
Update an existing customer. Only provided fields are changed.
delete_customer
Delete a customer record. This cannot be undone.
list_items
List a company's product/item catalog, with optional $filter/$orderBy and pagination.
get_item
Retrieve a single item by internal ID. Use list_items to find valid IDs.
create_item
Create a new product/item for a company. Use discovertaxcodes to find the correct taxCode so transactions referencing this item's itemCode calculate tax correctly.
update_item
Update an existing item. Only provided fields are changed.
delete_item
Delete an item. This cannot be undone.
list_locations
List a company's physical business locations, with optional $filter and pagination.
get_location
Retrieve a single location by internal ID. Use list_locations to find valid IDs.
create_location
Create a new physical business location for a company. locationCode must be unique within the company.
update_location
Update an existing location. Only provided fields are changed.
delete_location
Delete a location. This cannot be undone.
list_nexus
List a company's nexus declarations (where it has a tax obligation), with optional $filter and pagination.
get_nexus
Retrieve a single nexus declaration by ID. Use list_nexus to find valid IDs.
create_nexus
Declare a new nexus (tax obligation) for a company in a country/region. Use list_companies to find the companyId. For a state/region nexus, AvaTax also requires a parent country-level nexus to exist first (e.g. 'US' before 'US/CA') — this tool declares that automatically if it's missing.
update_nexus
Update an existing nexus declaration. Only provided fields are changed. Use get_nexus to check current values first.
delete_nexus
Delete a nexus declaration. This cannot be undone. Use get_nexus to verify the record first.
discover_tax_codes
Browse Avalara's global system tax code library (not company-specific). Use this to find the correct taxCode value for createitem, createtransaction line items, and createtaxcode.
list_company_tax_codes
List a company's own custom tax codes (distinct from Avalara's global library — use discovertaxcodes for that).
get_tax_code
Retrieve a single company custom tax code by ID. Use listcompanytax_codes to find valid IDs.
create_tax_code
Create a new custom tax code for a company. For standard tax codes, prefer discovertaxcodes.
update_tax_code
Update an existing company custom tax code. Only provided fields are changed.
delete_tax_code
Delete a company custom tax code. This cannot be undone.
create_transaction
Calculate tax on a new transaction. Use discovertaxcodes for line taxCode, discoverentityusecodes for exemptions, listcustomers/listitems for customerCode/itemCode. Set commit=true to finalize immediately, or call committransaction later. Use an '...Invoice' type (the default) unless this is a throwaway estimate — '...Order' types aren't saved by AvaTax.
get_transaction
Retrieve a single transaction by company code and transaction code, including line items and per-jurisdiction tax detail. Use listtransactions or createtransaction's response to find the code. Pass document_type matching how it was created (e.g. 'SalesOrder') — AvaTax defaults to looking for 'SalesInvoice' and returns not-found for any other type if this is omitted.
list_transactions
List transactions for a company, with optional $filter/$orderBy and pagination. AvaTax silently limits results to a recent date window when filter is omitted — pass a filter like "date ge '2024-01-01'" to see older transactions.
commit_transaction
Commit a transaction for tax reporting. Once committed it counts toward filings; use voidtransaction to reverse it instead of deleting. Pass documenttype matching how it was created — AvaTax defaults to 'SalesInvoice' and returns not-found for any other type if this is omitted.
void_transaction
Void a transaction, cancelling it for tax reporting purposes. Use gettransaction to verify the record first. Pass documenttype matching how it was created — AvaTax defaults to 'SalesInvoice' and returns not-found for any other type if this is omitted.
adjust_transaction
Correct a previously created transaction by replacing it with new data. Use gettransaction first to see the current state. Pass documenttype matching how it was created — AvaTax defaults to 'SalesInvoice' and returns not-found for any other type if this is omitted.
refund_transaction
Create a refund for a previously committed transaction. Pass document_type matching how it was created — AvaTax defaults to 'SalesInvoice' and returns not-found for any other type if this is omitted.
validate_credential
Check whether the stored Avalara Account ID, License Key, and environment are valid by pinging AvaTax.

How to set up Merge Agent Handler
In an mcp.json file, add the configuration below, and restart Cursor.
Learn more in the official documentation ↗
1{
2 "mcpServers": {
3 "agent-handler": {
4 "url": "https://ah-api-develop.merge.dev/api/v1/tool-packs/{TOOL_PACK_ID}/registered-users/{REGISTERED_USER_ID}/mcp",
5 "headers": {
6 "Authorization": "Bearer yMt*****"
7 }
8 }
9 }
10}
11Open your Claude Desktop configuration file and add the server configuration below. You'll also need to restart the application for the changes to take effect.
Make sure Claude is using the Node v20+.
Learn more in the official documentation ↗
1{
2 "mcpServers": {
3 "agent-handler": {
4 "command": "npx",
5 "args": [
6 "-y",
7 "mcp-remote@latest",
8 "https://ah-api-develop.merge.dev/api/v1/tool-packs/{TOOL_PACK_ID}/registered-users/{REGISTERED_USER_ID}/mcp",
9 "--header",
10 "Authorization: Bearer ${AUTH_TOKEN}"
11 ],
12 "env": {
13 "AUTH_TOKEN": "yMt*****"
14 }
15 }
16 }
17}Open your Windsurf MCP configuration file and add the server configuration below.
Click on the refresh button in the top right of the Manage MCP server page or in the top right of the chat box in the box icon.
Learn more in the official documentation ↗
1{
2 "mcpServers": {
3 "agent-handler": {
4 "command": "npx",
5 "args": [
6 "-y",
7 "mcp-remote@latest",
8 "https://ah-api.merge.dev/api/v1/tool-packs/<tool-pack-id>/registered-users/<registered-user-id>/mcp",
9 "--header",
10 "Authorization: Bearer ${AUTH_TOKEN}"
11 ],
12 "env": {
13 "AUTH_TOKEN": "<ah-production-access-key>"
14 }
15 }
16 }
17 }In Command Palette (Cmd+Shift+P on macOS, Ctrl+Shift+P on Windows), run "MCP: Open User Configuration".
You can then add the configuration below and press "start" right under servers. Enter the auth token when prompted.
Learn more in the official documentation ↗
1{
2 "inputs": [
3 {
4 "type": "promptString",
5 "id": "agent-handler-auth",
6 "description": "Agent Handler AUTH_TOKEN", // "yMt*****" when prompt
7 "password": true
8 }
9 ],
10 "servers": {
11 "agent-handler": {
12 "type": "stdio",
13 "command": "npx",
14 "args": [
15 "-y",
16 "mcp-remote@latest",
17 "https://ah-api-develop.merge.dev/api/v1/tool-packs/{TOOL_PACK_ID}/registered-users/{REGISTERED_USER_ID}/mcp",
18 "--header",
19 "Authorization: Bearer ${input:agent-handler-auth}"
20 ]
21 }
22 }
23}FAQs on using Merge's Avalara MCP server
FAQs on using Merge's Avalara MCP server
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