fix: Use KeyNotFoundException for not-found conditions in core Azure services#2703
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…services Replace plain Exception and ArgumentException with KeyNotFoundException in SubscriptionService, TenantService, and ResourceGroupService so that not-found conditions return HTTP 404 instead of 500/400. Fixes: microsoft/mcp-pr#396 Fixes: microsoft/mcp-pr#403 Fixes: microsoft/mcp-pr#404 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
tmeschter
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JasonYeMSFT,
KarishmaGhiya,
msalaman,
sandeep-sen,
srnagar,
wbreza and
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Pull request overview
Updates core Azure services to treat “not found” conditions as KeyNotFoundException so the command layer maps them to HTTP 404 (instead of 500/400), aligning behavior with existing patterns elsewhere in the repo.
Changes:
- Switched not-found throws in
SubscriptionServiceandTenantServicetoKeyNotFoundException. - Switched resource-group not-found throw in
ResourceGroupServicetoKeyNotFoundException. - Added an Azure server changelog entry describing the HTTP status code fix.
Show a summary per file
| File | Description |
|---|---|
| servers/Azure.Mcp.Server/changelog-entries/1779392230582.yaml | Adds changelog note for the not-found → 404 behavior change. |
| core/Azure.Mcp.Core/src/Services/Azure/Tenant/TenantService.cs | Uses KeyNotFoundException for tenant not-found lookups so callers map to 404. |
| core/Azure.Mcp.Core/src/Services/Azure/Subscription/SubscriptionService.cs | Uses KeyNotFoundException for subscription not-found lookups so callers map to 404. |
| core/Azure.Mcp.Core/src/Services/Azure/ResourceGroup/ResourceGroupService.cs | Uses KeyNotFoundException when resource group is missing during generic resource enumeration. |
Copilot's findings
- Files reviewed: 4/4 changed files
- Comments generated: 2
alzimmermsft
approved these changes
May 22, 2026
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Summary
Replace plain
ExceptionandArgumentExceptionwithKeyNotFoundExceptioninSubscriptionService,TenantService, andResourceGroupServiceso that not-found conditions return HTTP 404 instead of 500/400.Changes
SubscriptionService.csException(→500)KeyNotFoundException(→404)SubscriptionService.csArgumentException(→400)KeyNotFoundException(→404)SubscriptionService.csArgumentException(→400)KeyNotFoundException(→404)TenantService.csException(→500)KeyNotFoundException(→404)TenantService.csException(→500)KeyNotFoundException(→404)ResourceGroupService.csException(→500)KeyNotFoundException(→404)Why KeyNotFoundException?
AuthenticatedCommand.GetStatusCodealready mapsKeyNotFoundException→HttpStatusCode.NotFound(404). This is the same pattern used byBaseAzureResourceServiceandAcrServicefor not-found conditions.Validation
Fixes microsoft/mcp-pr#396
Fixes microsoft/mcp-pr#403
Fixes microsoft/mcp-pr#404
Invoking Livetests
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