Document Connected Library manifest layout

README.md

@@ -20,6 +20,10 @@ This repository contains two primary packages. For detailed development informat
 - [Web Interface](apps/frontend/README.md)
 - [Desktop App](apps/app/README.md)
 
+## Modrinth Plus
+
+Modrinth Plus adds a Connected Library for Git-hosted modpacks. A connected modpack repository must expose a public `modrinth-plus.json` manifest in the repository root. See [Connected Library documentation](docs/connected-library.md) and the [connected modpack template](templates/connected-modpack/README.md).
+
 ## Contributing
 
 We welcome contributions! Before submitting any contributions, please read our [contributing guidelines](https://docs.modrinth.com/contributing/getting-started/).

docs/connected-library.md

@@ -0,0 +1,64 @@
+# Connected Library
+
+Connected Library tracks a `.mrpack` export through a small JSON manifest hosted in a Git repository.
+
+## Repository layout
+
+The manifest must be named `modrinth-plus.json` and must live in the repository root:
+
+```text
+my-modpack-repo/
+|-- modrinth-plus.json
+|-- CHANGELOG.md
+|-- README.md
+`-- exports/
+    `-- MyModpack-1.0.0.mrpack
+```
+
+When a user enters a repository URL, Modrinth Plus checks these raw URLs:
+
+```text
+https://host/owner/repo/raw/branch/main/modrinth-plus.json
+https://host/owner/repo/raw/branch/master/modrinth-plus.json
+```
+
+You can also paste the raw `modrinth-plus.json` URL directly.
+
+## Manifest
+
+```json
+{
+  "schemaVersion": 1,
+  "name": "My Modpack",
+  "version": "1.0.0",
+  "versionId": "my-modpack-1.0.0",
+  "mrpackUrl": "https://git.example.com/owner/my-modpack/raw/branch/main/exports/MyModpack-1.0.0.mrpack",
+  "sha512": "replace-with-the-lowercase-sha512-of-the-mrpack",
+  "changelog": "Initial Connected Library release."
+}
+```
+
+Fields:
+
+- `schemaVersion`: Must be `1`.
+- `name`: Display name in Connected Library.
+- `version`: Human-readable version label.
+- `versionId`: Stable unique id for this release. Change it for every update.
+- `mrpackUrl`: Public HTTPS raw URL to the `.mrpack` file.
+- `sha512`: SHA-512 checksum of the `.mrpack` file.
+- `changelog`: Optional short release note shown in the app.
+
+## Release workflow
+
+1. Export a new `.mrpack` from the Modrinth App.
+2. Put it in `exports/` with a versioned filename.
+3. Calculate its SHA-512 checksum.
+4. Update `modrinth-plus.json` with the new `version`, `versionId`, `mrpackUrl`, `sha512`, and `changelog`.
+5. Commit and push the changes.
+6. In Modrinth Plus, click `Check for updates`.
+
+On Windows, calculate the checksum with:
+
+```powershell
+Get-FileHash -Algorithm SHA512 exports\MyModpack-1.0.0.mrpack
+```

packages/app-lib/src/api/connected_library.rs

@@ -399,7 +399,11 @@ async fn resolve_manifest(
     }
 
     Err(ErrorKind::InputError(format!(
-        "Could not fetch {MANIFEST_FILE_NAME}. Tried: {}",
+        concat!(
+            "Could not fetch {MANIFEST_FILE_NAME}. Make sure the file ",
+            "exists in the repository root or paste the raw manifest URL ",
+            "directly. Tried: {}"
+        ),
         errors.join("; ")
     ))
     .into())

templates/connected-modpack/CHANGELOG.md

@@ -0,0 +1,5 @@
+# Changelog
+
+## 1.0.0
+
+- Initial Connected Library release.

templates/connected-modpack/README.md

@@ -0,0 +1,26 @@
+# Connected Modpack Template
+
+Use this layout for a modpack repository that should work with Modrinth Plus Connected Library.
+
+```text
+.
+|-- modrinth-plus.json
+|-- CHANGELOG.md
+|-- README.md
+`-- exports/
+    `-- YourPack-1.0.0.mrpack
+```
+
+Update `modrinth-plus.json` after every exported `.mrpack` release. The file must stay in the repository root.
+
+Connect with either the repository URL:
+
+```text
+https://git.example.com/owner/your-pack
+```
+
+or the raw manifest URL:
+
+```text
+https://git.example.com/owner/your-pack/raw/branch/main/modrinth-plus.json
+```

templates/connected-modpack/exports/.gitkeep

@@ -0,0 +1 @@
+

templates/connected-modpack/modrinth-plus.json

@@ -0,0 +1,9 @@
+{
+  "schemaVersion": 1,
+  "name": "Your Pack",
+  "version": "1.0.0",
+  "versionId": "your-pack-1.0.0",
+  "mrpackUrl": "https://git.example.com/owner/your-pack/raw/branch/main/exports/YourPack-1.0.0.mrpack",
+  "sha512": "replace-with-the-lowercase-sha512-of-the-mrpack",
+  "changelog": "Initial Connected Library release."
+}