TaxJar through One
TaxJar is a tax compliance platform that provides APIs for sales tax calculation, reporting, and filing automation, allowing eCommerce businesses, marketplaces, and developers to manage multi-jurisdiction tax obligations and integrate tax workflows into checkout, billing, and back-office systems.
One exposes TaxJar through four MCP tools. The table below carries real action ids from One's knowledge base, so for a common operation you can skip search and go straight to reading the action's parameters.
How to run an action
- Find the action in the table below, or call
search_one_platform_actions with platform tax-jar if it is not listed.
- Call
get_one_action_knowledge with the action id. Do this every time, including for actions in this table. The table gives you the id, not the parameters.
- Call
execute_one_action with parameters copied from that knowledge.
Never guess a parameter name, a body field, or an enum value. The knowledge has the real schema, and a guessed field is either a 400 or a silent write of the wrong thing.
Before you start
Call list_one_integrations once and confirm TaxJar is connected. If it is missing, the user has not connected it: say so and point them at https://app.withone.ai rather than reaching for raw HTTP.
Each connection carries an access field. If it reports {"policy": "methods", "methods": ["GET"]} the agent is read-only here, so plan a read-only answer instead of attempting a write that will be refused.
Before a write
Creates, updates, deletes and sends land on a real TaxJar account and cannot be recalled. State the action and the specific target in one line before the first write in a task, and let the user stop you. Reads need no confirmation.
Actions
Customers
| Action |
Method |
Path |
Action id |
| List Customers |
GET |
/v2/customers |
conn_mod_def::GLWDVl6s41A::UJn51QZ3Tg6MnnjATfCn7w |
| Show a Customer |
GET |
/v2/customers/{{customerId}} |
conn_mod_def::GLWDVmyAAvA::6JsP6WfITbGhxntTaNT9Eg |
| Create Customer |
POST |
/v2/customers |
conn_mod_def::GLWDVk8zCPA::cRS5OJoGSKq-xLGAt-bKTg |
| Delete a Customer |
DELETE |
/v2/customers/{{customerId}} |
conn_mod_def::GLWDVniJ1EA::QpEroI9oQjChVm37CjqDWA |
| Update a Customer |
PUT |
/v2/customers/{{customerId}} |
conn_mod_def::GLWDVxWQj0A::g1X4yt62TM2G_0OI23kzRg |
RefundTransactions
| Action |
Method |
Path |
Action id |
| Show Refund Transaction |
GET |
/v2/transactions/refunds/{{transactionId}} |
conn_mod_def::GLWDWAb4ZRA::17R1hbZVSzamdSFQxy5r9Q |
| Create Refund Transaction |
POST |
/v2/transactions/refunds |
conn_mod_def::GLWDWJX2Zcg::Fvca6tDQSleBct2yuMLezQ |
| Delete a Refund Transaction |
DELETE |
/v2/transactions/refunds/{{transactionId}} |
conn_mod_def::GLWDV64ZS9A::zg2I1rFhRhC-BqIvPlF7Zg |
| Update a Refund Transaction |
PUT |
/v2/transactions/refunds/{{transactionId}} |
conn_mod_def::GLWDWJXuoYA::8je1_okZQOCRCL7X7v0e0g |
OrderTransactions
| Action |
Method |
Path |
Action id |
| Delete an Order Transaction |
DELETE |
/v2/transactions/orders/{{transactionId}} |
conn_mod_def::GLWDV64M3Dg::QQrPOhCUT8O5TnJRuXRAYQ |
| Update Order Transaction |
PUT |
/v2/transactions/orders/{{transactionId}} |
conn_mod_def::GLWDWK6DkbA::tg3ST_2IQ4OGbQT7AvI2EA |
Transactions
| Action |
Method |
Path |
Action id |
| Show an Order Transaction |
GET |
/v2/transactions/orders/{{transactionId}} |
conn_mod_def::GLWDWN7F7Ig::pm7CKOPTTj2MWiwVezt0iw |
| Create Order Transaction |
POST |
/v2/transactions/orders |
conn_mod_def::GLWDWK5pJ_g::CmWNV1o_SmKDtvuUAciLJA |
Categories
| Action |
Method |
Path |
Action id |
| List Tax Categories |
GET |
/v2/categories |
conn_mod_def::GLWDVmjPXtA::kIFfQWtfQc-k71x2YLzG3A |
NexusRegions
| Action |
Method |
Path |
Action id |
| List Nexus Regions |
GET |
/v2/nexus/regions |
conn_mod_def::GLWDVwj88Jg::Mxv_LvhZRYG6fkJCYQKxng |
Taxes
| Action |
Method |
Path |
Action id |
| Calculate Sales Tax for an Order |
POST |
/v2/taxes |
conn_mod_def::GLWDVw-tY1A::9ELWz97hQ_SKHwSfT0iCEQ |
SummaryRates
| Action |
Method |
Path |
Action id |
| Summary Rates |
GET |
/v2/summary_rates |
conn_mod_def::GLWDVxURl1g::bKjhRh3jTj2p9U0rn-Vjtw |
SalesTaxRates
| Action |
Method |
Path |
Action id |
| Get Sales Tax Rates for a Location |
GET |
/v2/rates/{{zip}} |
conn_mod_def::GLWDVyY4qKA::Y_B8VlxMQ6qZUUHsXUOyuA |
Orders
| Action |
Method |
Path |
Action id |
| List Orders |
GET |
/v2/transactions/orders |
conn_mod_def::GLWDV7IXltg::WgKPxrsmTTC4ntGxRt0WzQ |
Refunds
| Action |
Method |
Path |
Action id |
| List Refunds |
GET |
/v2/transactions/refunds |
conn_mod_def::GLWDV7aMiOA::OnxwMZx7Ru6ExxVLNU5mFg |
Addresses
| Action |
Method |
Path |
Action id |
| Validate Address |
POST |
/v2/addresses/validate |
conn_mod_def::GLWDWVf-Llg::EMav-LAyRmO9SYSk5VHtCw |
When a call fails
The error comes from TaxJar, not from One. A 400 or 422 means your parameters do not match the schema, so re-read the knowledge and fix the field. A 401 or 403 means the connection needs re-authorizing, which no retry will fix. A 404 means the id is not on this account. A 429 means slow down. Never retry a write more than once: the first attempt may have landed.
Full catalog: https://www.withone.ai/knowledge/tax-jar
Integration knowledge by One (withone.ai), licensed under One-Knowledge-1.0. Attribution must be preserved in derivative works.
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