---
title: "Validate an action expression."
method: GET
path: "/v1/rules/validate-expression"
tags: ["rules"]
---

# Validate an action expression.

`GET /v1/rules/validate-expression`

Validate an action expression as used in rule actions. Returns whether the submitted expression is valid.
If the expression is invalid, a 422 validation error is returned instead.

## Query parameters

- `expression` string, required

## Headers

- `X-Trace-Id` string, uuid

## Response `200`

The expression is valid.

- object
  - `valid` boolean

## Other responses

- `400` — Bad request
- `401` — Unauthenticated
- `404` — Page not found
- `422` — Validation error. The body will have the exact details.
- `500` — Internal exception

---

[API](https://skmtc.dev/firefly-iii/apis/firefly-iii-api-develop.md) · [All operations](https://skmtc.dev/firefly-iii/apis/firefly-iii-api-develop/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/firefly-iii/firefly-iii-api-develop/revisions/8a1f6472e04b/schema)