Server branding (icons & logos)

A Dockyard server can advertise a logo, homepage, and description in the MCP handshake's serverInfo (SEP-973). A host MAY render your icon beside the server's name in its UI. Rendering is client-dependent — serverInfo.icons is a hint every host is free to ignore or fall back to a generic icon — so providing icons is necessary but not sufficient for a logo to appear.

Set branding on the server

Branding lives on server.Info. The live server emits it in serverInfo on both the legacy 2025-11-25 and stateless 2026-07-28 lifecycles.

import "github.com/hurtener/dockyard/runtime/server"

srv, err := server.New(server.Info{
	Name:        "customer-health",
	Title:       "Customer Health",
	Version:     "0.1.0",
	Description: "Customer health scores and account signals.",
	WebsiteURL:  "https://acme.example/customer-health",
	Icons: []server.Icon{
		{
			Src:      "https://acme.example/logo.png",
			MIMEType: "image/png",
			Sizes:    []string{"48x48", "96x96"},
			Theme:    server.IconThemeLight,
		},
		{
			// A data: URI inlines the bytes — no separate hosting or auth to
			// worry about.
			Src:   "data:image/svg+xml;base64,PHN2Zz4uLi48L3N2Zz4=",
			Theme: server.IconThemeDark,
		},
	},
}, opts)

Field rules (enforced by server.New):

• Icon.Src is required and must be an https:// URL or a data:image/… URI (checked on the raw value, so no surrounding whitespace). An http://, otherwise-schemed, or non-image data: src is rejected — most hosts drop a mixed-content icon anyway, and an icon is an image.
• Icon.MIMEType is optional but recommended for an https:// src (prefer PNG or SVG). Icon.Sizes lists available sizes (["48x48"], ["any"] for SVG). Icon.Theme is IconThemeLight or IconThemeDark; provide both as two entries so a host can pick per its active theme.
• WebsiteURL must be an absolute https:// URL when set.

Set no branding and serverInfo is byte-for-byte what it was — the keys are omitted entirely.

Declare branding in the manifest too

dockyard.app.yaml carries the same branding declaratively, so tooling has a record of it:

name: customer-health
title: Customer Health
version: 0.1.0
description: Customer health scores and account signals.
website_url: https://acme.example/customer-health
icons:
  - src: https://acme.example/logo.png
    mime_type: image/png
    sizes: ["48x48", "96x96"]
    theme: light
  - src: https://acme.example/logo-dark.png
    mime_type: image/png
    theme: dark

dockyard validate checks the same rules (src scheme, theme, website URL).

The manifest is declarative — the server emits from server.Info

The runtime library never reads dockyard.app.yaml (it can't — the manifest package is internal to Dockyard's own module). The manifest icons block is the declarative record for tooling and review; the live server advertises from server.Info. Keep the two in step. (D-203)

Why the logo still might not show

If your icon is valid and reachable but the host shows a generic icon, the gap is on the client:

• The host UI hasn't implemented serverInfo.icons. SEP-973 is recent and rendering is optional — many clients ignore it today. This is not a server bug.
• The icon URL isn't publicly reachable from the client — behind auth, a hotlink block, or a private network. Prefer a public https:// URL or a data: URI.
• A generic/missing MIME type — set MIMEType explicitly.
• No Title — some hosts label with Title (falling back to Name); set it so the branding has text alongside the icon.

Your /favicon.ico is unrelated: that's plain HTTP static serving, not the MCP serverInfo channel a host reads.

See also

• Scaffold a server
• Validate + test
• OAuth protected resource