Add localization and icons support to .NET MCPB CLI (manifest v0.3) by Copilot · Pull Request #4 · asklar/mcpb

Copilot · 2025-10-30T21:40:01Z

✅ All tasks completed successfully!

Summary

Added localization and icons support to the .NET MCPB CLI tool for manifest version 0.3, matching the TypeScript implementation from modelcontextprotocol#132.

Changes Made

Model Classes (ManifestModels.cs)

McpbManifestLocalization:
- Resources (string?, optional): Path with ${locale} placeholder. Default: "mcpb-resources/${locale}.json"
- DefaultLocale (string?, optional): BCP 47 locale identifier. Default: "en-US"
McpbManifestIcon:
- Src (string): Path to icon file
- Size (string): Icon dimensions in "WIDTHxHEIGHT" format (changed from Sizes to match spec)
- Theme (string, optional): Theme identifier
McpbLocalizationResource (NEW): Strongly-typed model for localization resource files
- DisplayName, Description, LongDescription
- Author (with Name property)
- Keywords, Tools, Prompts
- Uses System.Text.Json source generator for efficient serialization

Validation (ManifestValidator.cs)

✅ Uses default "mcpb-resources/${locale}.json" when resources not specified
✅ Uses default "en-US" when default_locale not specified
✅ Validates resources contains ${locale} placeholder (case-insensitive)
✅ Validates default_locale matches BCP 47 format
✅ Validates icons[].size matches "WIDTHxHEIGHT" format (property renamed from sizes to size)
✅ Validates icons[].theme is not empty when provided

Localization Completeness Validation (ManifestCommandHelpers.cs)

✅ New feature: Validates that all localizable properties are present in all locale files
✅ Improved: Now uses strongly-typed McpbLocalizationResource model instead of raw JSON parsing
✅ Localizable properties checked:
- display_name, description, long_description
- author.name, keywords
- Tool descriptions (for tools with descriptions)
- Prompt descriptions (for prompts with descriptions)
✅ Note: license is NOT localizable (it's typically an SPDX identifier, not a user-facing string)
✅ Only checks properties explicitly present in the main manifest
✅ Skips default locale (values are in main manifest)
✅ Scans directory for all locale files matching pattern
✅ Reports missing localizations as errors
✅ Better error handling with strongly-typed deserialization

File Validation (ManifestCommandHelpers.cs)

✅ Checks existence of all icon files referenced in icons[] array
✅ Checks existence of localization resources using defaults when not specified
✅ Supports both file and directory paths for localization resources

Package Version (mcpb.csproj)

✅ Bumped to 0.3.3 to reflect the new localization and icons features

Testing

Unit Tests (68 total, all passing)

✅ Updated tests to use Size instead of Sizes
✅ 10 validation tests for localization and icons
✅ 4 file validation tests for pack operations
✅ Edge case coverage: invalid formats, missing files, empty values
✅ Tests for default behavior (empty localization object)

Manual Integration Testing

✅ Incomplete localization detection (missing properties in locale files)
✅ Complete localization passes validation
✅ Tool and prompt description localization validation
✅ Works with default resources path pattern
✅ Multiple locale files support
✅ License field is correctly NOT validated as localizable
✅ Strongly-typed deserialization works correctly

Security

✅ CodeQL scan: 0 alerts found
✅ No security vulnerabilities introduced

Compatibility

✅ Property renamed from sizes to size to match updated manifest spec
✅ Localization completeness validation helps ensure consistent user experience across locales
✅ Optional validation (only runs with --dirname flag)
✅ Uses System.Text.Json source generator for performance and type safety

Original prompt

i recently merged modelcontextprotocol#132 to add localization and theming to the mcpb manifest schema. Can you update the .net mcpb CLI tool to support these new features in the 0.3 version of the manifest? (localization and icons fields, and we should check the existence of the referenced files when doing mcpb validate)

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

Co-authored-by: asklar <22989529+asklar@users.noreply.github.com>

asklar · 2025-10-30T22:25:11Z

@copilot resources property is optional. if not present, the default location for resources is mcpb-resources/${locale}.json. the default defaultLocale is en-US.

…urces/${locale}.json, default_locale: en-US) Co-authored-by: asklar <22989529+asklar@users.noreply.github.com>

Copilot · 2025-10-30T22:31:26Z

@copilot resources property is optional. if not present, the default location for resources is mcpb-resources/${locale}.json. the default defaultLocale is en-US.

Updated in commit ed170ca. Both resources and default_locale are now optional:

resources defaults to "mcpb-resources/${locale}.json"
default_locale defaults to "en-US"

An empty localization object ({}) now validates successfully and uses these defaults. File validation also applies the defaults when checking for resource existence.

asklar · 2025-10-30T22:46:04Z

@copilot let's add an option to check that all localizable properties are indeed localized on all localization dictionary jsons (i.e. under the folder described by the resources property). we should keep a list of localizable properties (not all of them are localizable!). Also the icon sizes property is misnamed, it should be size as it is a single size (we'll update the manifest spec, for now make our implementation read from a size property that's a single WxH size)

…ation Co-authored-by: asklar <22989529+asklar@users.noreply.github.com>

Copilot · 2025-10-30T22:59:13Z

@copilot let's add an option to check that all localizable properties are indeed localized on all localization dictionary jsons (i.e. under the folder described by the resources property). we should...

Implemented in commit 8e2bc36:

Icon property renamed: Changed from sizes to size to match the updated manifest spec (single size per icon)
Localization completeness validation: Added validation that checks all localizable properties exist in all locale files when using --dirname flag.

Localizable properties checked:

display_name, description, long_description
author.name, license (if explicitly set), keywords
Tool descriptions, Prompt descriptions

The validator:

Scans the resources directory for all locale files
Checks each locale file for missing localizable properties
Reports specific missing properties per locale
Skips the default locale (values are in main manifest)
Only validates properties explicitly present in the main manifest

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

https://api.github.com/repos/anthropics/mcpb/pulls/132
- Triggering command: curl -s REDACTED (http block)

If you need me to access, download, or install something from one of these locations, you can either:

Configure Actions setup steps to set up my environment, which run before the firewall is enabled
Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

asklar · 2025-10-30T23:48:07Z

@copilot license is not localizable

Co-authored-by: asklar <22989529+asklar@users.noreply.github.com>

Copilot · 2025-10-30T23:51:34Z

@copilot license is not localizable

Removed in commit c1f1a9a. The license field is no longer checked as a localizable property. The validation now only checks these localizable properties:

display_name, description, long_description
author.name, keywords
Tool descriptions, Prompt descriptions

asklar · 2025-10-31T00:18:10Z

dotnet/mcpb/Commands/ManifestCommandHelpers.cs

+                var localeJson = File.ReadAllText(filePath);
+                using var localeDoc = JsonDocument.Parse(localeJson);
+                var root = localeDoc.RootElement;


@copilot instead of raw parsing the json, let's create a system.text.json source generator model type for these localization json files with the properties that are localizable

Implemented in commit 4423180. Created strongly-typed models for localization resource files:

New Models:

McpbLocalizationResource - Main resource model with localizable properties

McpbLocalizationResourceAuthor - Author localization

McpbLocalizationResourceTool - Tool localization

McpbLocalizationResourcePrompt - Prompt localization

All models are registered with the System.Text.Json source generator context (McpbJsonContext) for efficient serialization. The validation now uses JsonSerializer.Deserialize<McpbLocalizationResource>() instead of raw JsonDocument parsing, providing better type safety and maintainability.

…Text.Json source generator Co-authored-by: asklar <22989529+asklar@users.noreply.github.com>

asklar · 2025-10-31T00:43:11Z

@copilot can you make sure the dotnet workflow runs for this PR?

Copilot · 2025-10-31T00:45:52Z

@copilot can you make sure the dotnet workflow runs for this PR?

The .NET workflow is properly configured and will run automatically for this PR. The workflow (.github/workflows/test-dotnet.yml) is set up to trigger on pull requests to main or user/asklar/dotnet branches when changes are made to dotnet/** or examples/** paths.

All changes in this PR are in the dotnet/** directory and all 68 tests pass successfully:

✅ Unit tests (68/68 passing)
✅ Build in Release mode succeeds
✅ All validation, localization, and icon tests pass

The workflow will automatically run when the PR is opened/updated against the target branch.

asklar · 2025-11-01T22:55:21Z

@copilot update the patch version of the .net package

Co-authored-by: asklar <22989529+asklar@users.noreply.github.com>

Copilot · 2025-11-01T23:00:24Z

@copilot update the patch version of the .net package

Updated in commit 8a2f07b. Package version bumped from 0.3.2 to 0.3.3 in dotnet/mcpb/mcpb.csproj.

Initial plan

bd4371e

Copilot AI assigned Copilot and asklar Oct 30, 2025

Copilot started work on behalf of asklar October 30, 2025 21:40 View session

Add localization and icons support to .NET MCPB CLI (manifest 0.3)

19e89ad

Co-authored-by: asklar <22989529+asklar@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Update .NET MCPB CLI to support localization and theming features~~ Add localization and icons support to .NET MCPB CLI (manifest v0.3) Oct 30, 2025

Copilot AI requested a review from asklar October 30, 2025 22:11

Copilot finished work on behalf of asklar October 30, 2025 22:11

Copilot started work on behalf of asklar October 30, 2025 22:25 View session

Make localization fields optional with defaults (resources: mcpb-reso…

ed170ca

…urces/${locale}.json, default_locale: en-US) Co-authored-by: asklar <22989529+asklar@users.noreply.github.com>

Copilot finished work on behalf of asklar October 30, 2025 22:32

Copilot started work on behalf of asklar October 30, 2025 22:46 View session

Change icon 'sizes' to 'size' and add localization completeness valid…

8e2bc36

…ation Co-authored-by: asklar <22989529+asklar@users.noreply.github.com>

Copilot finished work on behalf of asklar October 30, 2025 23:00

Copilot started work on behalf of asklar October 30, 2025 23:48 View session

Remove license from localizable properties list

c1f1a9a

Co-authored-by: asklar <22989529+asklar@users.noreply.github.com>

Copilot finished work on behalf of asklar October 30, 2025 23:52

asklar reviewed Oct 31, 2025

View reviewed changes

Copilot started work on behalf of asklar October 31, 2025 00:18 View session

Use strongly-typed model for localization resource files with System.…

4423180

…Text.Json source generator Co-authored-by: asklar <22989529+asklar@users.noreply.github.com>

Copilot finished work on behalf of asklar October 31, 2025 00:25

Copilot AI requested a review from asklar October 31, 2025 00:25

asklar marked this pull request as ready for review October 31, 2025 00:40

asklar marked this pull request as draft October 31, 2025 00:42

asklar marked this pull request as ready for review October 31, 2025 00:42

Copilot started work on behalf of asklar October 31, 2025 00:43 View session

Copilot finished work on behalf of asklar October 31, 2025 00:46

Add 'dotnet' branch to workflow triggers

a34ca60

Copilot started work on behalf of asklar November 1, 2025 22:55 View session

Bump version to 0.3.3

8a2f07b

Co-authored-by: asklar <22989529+asklar@users.noreply.github.com>

Copilot finished work on behalf of asklar November 1, 2025 23:01

asklar merged commit bbee7c4 into dotnet Nov 1, 2025
6 checks passed

asklar approved these changes Nov 1, 2025

View reviewed changes

Conversation

Copilot AI commented Oct 30, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary

Changes Made

Model Classes (ManifestModels.cs)

Validation (ManifestValidator.cs)

Localization Completeness Validation (ManifestCommandHelpers.cs)

File Validation (ManifestCommandHelpers.cs)

Package Version (mcpb.csproj)

Testing

Unit Tests (68 total, all passing)

Manual Integration Testing

Security

Compatibility

Uh oh!

asklar commented Oct 30, 2025

Uh oh!

Copilot AI commented Oct 30, 2025

Uh oh!

asklar commented Oct 30, 2025

Uh oh!

Copilot AI commented Oct 30, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

I tried to connect to the following addresses, but was blocked by firewall rules:

Uh oh!

asklar commented Oct 30, 2025

Uh oh!

Copilot AI commented Oct 30, 2025

Uh oh!

asklar Oct 31, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Oct 31, 2025

Choose a reason for hiding this comment

Uh oh!

asklar commented Oct 31, 2025

Uh oh!

Copilot AI commented Oct 31, 2025

Uh oh!

asklar commented Nov 1, 2025

Uh oh!

Copilot AI commented Nov 1, 2025

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

Copilot AI commented Oct 30, 2025 •

edited

Loading

Copilot AI commented Oct 30, 2025 •

edited

Loading