Velopack Feed Endpoint

Dynamic feed endpoint for Velopack applications. It returns the releases.{channel}.json document the stock Velopack client expects, built from the database on every request so it can honor per-client logic — most importantly required intermediate builds.

Overview

FaynoSync serves Velopack feeds two ways:

• Static (CDN, default) — FaynoSync materializes releases.{channel}.json to object storage and the client reads it directly. No API involvement. See Velopack updater.
• Dynamic (this endpoint) — the client points its UPDATE_URL at the API route. FaynoSync builds the feed per request, which lets it cap the feed at a required intermediate version for the reporting client. Object storage can't do this because it ignores query parameters.

The channel is parsed from the requested file name (releases.{channel}.json), so it is not a separate path parameter.

Endpoint

GET /velopack/{owner}/{app}/{platform}/{arch}/releases.{channel}.json

The same route also resolves package downloads: a request whose final segment ends in .nupkg is answered with a 302 redirect to the artifact's real storage link.

URL Parameters

Parameter	Type	Required	Description
owner	string	✅	Name of your admin user
app	string	✅	Name of the application
platform	string	✅	Platform (e.g., darwin, windows, linux)
arch	string	✅	Architecture (e.g., arm64, amd64)
channel	string	✅	Parsed from the file name releases.{channel}.json (e.g., nightly)

Query Parameters

Parameter	Type	Required	Description
localVersion	string	❌	The client's current version. When set and a required intermediate build exists between it and the latest, the feed is capped so the highest Full is that intermediate version.
id	string	❌	Velopack package id. If present it must equal app, otherwise the request is rejected.

Example Request

curl --location 'http://localhost:9000/velopack/admin/HelloVelopack/darwin/arm64/releases.nightly.json?localVersion=1.0.0&id=HelloVelopack'

Response

Success Response (200 OK)

Content-Type: application/json. The body is the Velopack feed in PascalCase — the exact shape the stock client parses:

{
  "Assets": [
    {
      "PackageId": "HelloVelopack",
      "Version": "1.0.1",
      "Type": "Full",
      "FileName": "HelloVelopack-1.0.1-nightly-full.nupkg",
      "SHA1": "…",
      "SHA256": "…",
      "Size": 13355895,
      "NotesMarkdown": "- fix crash on startup",
      "NotesHTML": "<ul><li>fix crash on startup</li></ul>"
    },
    {
      "PackageId": "HelloVelopack",
      "Version": "1.0.1",
      "Type": "Delta",
      "FileName": "HelloVelopack-1.0.1-nightly-delta.nupkg",
      "SHA1": "…", "SHA256": "…", "Size": 189039
    },
    {
      "PackageId": "HelloVelopack",
      "Version": "1.0.0",
      "Type": "Full",
      "FileName": "HelloVelopack-1.0.0-nightly-full.nupkg",
      "SHA1": "…", "SHA256": "…", "Size": 13355733
    }
  ]
}

In the example above 1.0.2 is published but 1.0.1 is marked intermediate, so a client on localVersion=1.0.0 is stepped to 1.0.1 first — the feed is capped there. On the next check (now on 1.0.1) it proceeds to the latest.

Empty feed

When there are no published velopack releases for the tuple, or the feed can't be built, the endpoint returns 200 OK with an empty document rather than an error:

{ "Assets": [] }

Package redirect (302)

A .nupkg request on this route redirects to the package's public storage link:

GET /velopack/admin/HelloVelopack/darwin/arm64/HelloVelopack-1.0.1-nightly-full.nupkg
→ 302 Found  (Location: <storage link>)

Configuration Requirements

1. Updater: the platform must have the velopack updater configured.
2. Channel, platform, arch: Velopack releases require all three — each (channel, platform, arch) tuple has its own feed.
3. Client UPDATE_URL: point it at {api_base}/velopack/{owner}/{app}/{platform}/{arch}; the stock client appends /releases.{channel}.json.

Comparison with the static feed

Aspect	Static feed (CDN)	This endpoint (API)
Who serves it	Object storage / CDN	FaynoSync, per request
API load per check	~none	every check
Required intermediate builds	❌	✅ (localVersion)
Enabled by	Always on for velopack apps	Point UPDATE_URL at the API

Notes

• Channel from file name — the channel is not a path parameter; it is read from releases.{channel}.json.
• Feed format — PascalCase keys; Full and Delta asset types; hashes are taken verbatim from the uploaded releases.{channel}.json.
• Related — Velopack updater, Required Intermediate Build, Velopack example app.