---
title: "lookup_tax_parameter"
method: POST
path: "/v1/tools/lookup_tax_parameter"
tags: ["tools"]
---

# lookup_tax_parameter

`POST /v1/tools/lookup_tax_parameter`

## Request

- Base URL: `https://opentax.invaro.ai`
- URL: `https://opentax.invaro.ai/v1/tools/lookup_tax_parameter`
- Auth: one of:
  - HTTP bearer
  - none

Look up the current-law dollar amounts behind a question ('standard deduction', 'CTC phase-out threshold', 'tips deduction cap') with their statutory citations and validity windows. Use this to fact-check ANY tax number before stating it — your training data likely predates the OBBBA.

## Headers

- `X-OpenTax-Return-Id` string

## Request body

- object
  - `query` string, required: plain-English search, e.g. 'standard deduction'
  - `asOf` string

## Response `200`

ok:true with the computed value, line set or lookup hits; ok:false with error.code when the engine refuses (NEEDS_FACTS, NO_APPLICABLE_RULE, UNHANDLED_ENUM_CASE)

- object
  - `ok` boolean, required

## Other responses

- `400`: transport-level error
- `401`: transport-level error
- `429`: transport-level error

---

[API](https://skmtc.dev/invaro/apis/opentax-rest-api.md) · [All operations](https://skmtc.dev/invaro/apis/opentax-rest-api/llms.txt) · [OpenAPI document](https://skmtc.dev/invaro/apis/opentax-rest-api/revisions/61fd3e3e6018?raw)