---
title: "Preview a single If/Conditional Check leaf - the same lookup evaluate() uses internally (Variable/Expression/Time/GPIO Pin/Sun), before any comparator/Value is applied. Backs the If condition editor's \"Show Current Value\" button, so picking the right Value to compare against isn't guesswork."
method: GET
path: "/api/fppd/condition/preview"
tags: ["fppd"]
---

# Preview a single If/Conditional Check leaf - the same lookup evaluate() uses internally (Variable/Expression/Time/GPIO Pin/Sun), before any comparator/Value is applied. Backs the If condition editor's "Show Current Value" button, so picking the right Value to compare against isn't guesswork.

`GET /api/fppd/condition/preview`

When a "comparator" param is also supplied (the consolidated eye-preview modal's full-leaf mode), also evaluates Value the same way Value is unconditionally evaluated at runtime and applies the comparator, returning the RHS value and the boolean result too - reuses ConditionNode::PreviewLeafResult(), the exact same evaluation path a real saved leaf's evaluate() takes, so this can never drift from runtime behavior.

## Query parameters

- `source` string
- `name` string
- `comparator` string
- `value` string
- `not` string

## Response `200`

{"found": true, "value": "..."} (source/name-only mode) or

---

[API](https://skmtc.net/falconchristmas/apis/fpp-api.md) · [All operations](https://skmtc.net/falconchristmas/apis/fpp-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/falconchristmas/fpp-api/versions/6fa524e15dd4/schema)