---
search:
  tags:
    - Operations
    - PUT
seo:
  description: >-
    Owner-only. Replaces the icon as a unit — both emoji and bg are required;
    there is no… Reference for the PUT /app/{id}/icon endpoint in the Charming
    API API.
sidebar:
  badge: PUT
  label: Set the home-screen / favicon icon (emoji + bg)
title: Set the home-screen / favicon icon (emoji + bg)
type: openapi-operation
---
Owner-only. Replaces the icon as a unit — both `emoji` and `bg` are required; there is no partial / PATCH semantics. Stricter than `PUT /app/{id}`: invalid `emoji` or `bg` is rejected with 400 `invalid_icon` rather than silently dropped and folded into `warnings[]` (that warn-and-drop contract is for agent publishes, where a typo must never fail). Last-writer-wins with a near-simultaneous agent publish; the rendered icon SVG / PNG caches revalidate on next read via their content-derived ETag.

<Operation source="reference" id="set-app-icon" />

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