feat(agents): add .NET code deploy support (dotnet_8/9/10 runtimes)

[v1212]

Summary

Adds .NET runtime support (dotnet_8, dotnet_9, dotnet_10) to the code deploy (ZIP upload) path introduced in #8146. This enables deploying .NET agent source code directly via ZIP upload without requiring Docker/ACR, alongside the existing Python support.

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Init Flow Changes

Deploy Mode Prompt

The code deploy option now appears for both Python and .NET projects (detected via .csproj/.fsproj files). For projects that are neither Python nor .NET, the code deploy option remains hidden.

Existing Code -> Code Deploy (.NET)

azd ai agent init           # non-empty dir with .csproj
-> "Use the code in the current directory"
-> Agent name
-> Deploy mode -> Source Code (ZIP upload)
-> Runtime -> .NET 9 / .NET 8 / .NET 10
-> Entry point -> HelloWorld.dll (auto-detected from .csproj)
-> Dependency resolution -> Remote build / Bundled
-> Protocols
-> Model -> Use existing model deployment(s)
-> Subscription -> select
-> Foundry Project -> select
-> Writes agent.yaml (with code_configuration, runtime: dotnet_9), azure.yaml (language: csharp, no docker block)

Runtime Filtering

promptCodeConfig() now filters runtime choices based on detected project type:

• .NET project only (has .csproj/.fsproj, no .py/requirements.txt): Shows only .NET 9, .NET 8, .NET 10
• Python project only (has .py/requirements.txt, no .csproj): Shows only Python 3.11, 3.12, 3.13
• Mixed or unknown: Shows all 6 runtime options

Language Detection in azure.yaml

Both init paths (template and from-code) correctly set language: csharp when a dotnet runtime is selected, fixing a bug where code deploy always hardcoded language: python.

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Deploy Path Changes

Bundled Mode (dependency_resolution: bundled)

For .NET agents in bundled mode, packageDotnetBundled():

1. Runs dotnet publish -c Release -r linux-x64 --self-contained false -o <temp-dir>
2. ZIPs the published output (ready-to-run binaries for Linux)
3. Uploads via the same multipart form-data POST used for Python

Remote Build Mode (dependency_resolution: remote_build)

For .NET agents in remote build mode:

1. ZIPs source code (.cs, .csproj files etc.) excluding build artifacts
2. Server-side Oryx build handles dotnet publish on the remote environment

Entry Point Prefix

.NET agents use dotnet <entry_point> as the startup command (e.g., ["dotnet", "HelloWorld.dll"]), while Python uses python <entry_point>.

250 MB ZIP Size Limit

Enforced for all code deploy packages (both Python and .NET) with a clear error message.

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Files Modified

File	Change
init_from_code.go	Add isDotnetProject() helper, detectDefaultEntryPoint() for .dll/.csproj, filter runtime choices by project type, update showCodeDeploy to include .NET, fix noPrompt default for dotnet
init_from_code_test.go	Unit tests for detectDefaultEntryPoint() with dotnet scenarios
init.go	Fix language: python hardcoding bug -- now checks runtime prefix for csharp; update showCodeDeploy to use isDotnetProject()
map.go	Map dotnet_8/9/10 runtimes to API format with "dotnet" command prefix
map_test.go	Round-trip tests for dotnet code configuration API mapping
service_target_agent.go	Add packageDotnetBundled() with dotnet publish + output capture in errors; display dotnet prefix in deploy output; add bytes import; enforce 250 MB ZIP limit
config.go	Add TODO comment to CodeDeployRegions for future dynamic discovery

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How to Build

cd cli/azd/extensions/azure.ai.agents
go build ./...
go test ./...
go vet ./...

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Manual Test Steps

Prerequisites

• Azure subscription with a Foundry project in a supported region (westus2, canadacentral, northcentralus)
• A model deployment (e.g. gpt-4o, gpt-5.1) in your Foundry project
• .NET SDK 9 installed locally (for bundled mode)
• azd CLI installed, logged in (azd auth login)
• Build the extension: cd cli/azd/extensions/azure.ai.agents && azd x build

Test 1: .NET Code Deploy with Remote Build

# 1. Clone a .NET agent sample (e.g., hello-world-dotnet-invocations)
mkdir test-dotnet-code-deploy && cd test-dotnet-code-deploy

# 2. Create a minimal .NET agent project with agent.yaml containing:
#   code_configuration:
#     runtime: dotnet_9
#     entry_point: HelloWorld.dll
#     dependency_resolution: remote_build

# 3. Init with existing Foundry project
azd ai agent init --project-id "<your-arm-resource-id>"
# Expected prompts:
#   1. Deploy mode -> Source Code (ZIP upload)
#   2. Runtime -> .NET 9 (only .NET options shown since it's a .NET project)
#   3. Entry point -> HelloWorld.dll (auto-detected from .csproj)
#   4. Dependency resolution -> Remote build
#   5. Protocols -> invocations
#   6. Model -> select existing deployment

# 4. Verify azure.yaml
Get-Content azure.yaml | Select-String "language"
# Expect: language: csharp

# 5. Deploy
azd deploy hello-world-dotnet-invocations
# Expect: "Packaging code" -> "Creating agent" -> "Agent is active!"

# 6. Invoke (wait ~30s for cold start)
azd ai agent invoke "What is 2+2?"
# Expect: streaming response with model reply

Test 2: .NET Code Deploy with Bundled Mode

# Same project as above, update agent.yaml:
#   dependency_resolution: bundled

azd deploy hello-world-dotnet-invocations
# Expect: "Publishing .NET project" -> "Packaging code" -> "Creating agent" -> done
# The deploy runs `dotnet publish -c Release -r linux-x64 --self-contained false` locally

azd ai agent invoke --new-session "Hello bundled dotnet!"
# Expect: streaming response

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Test Results

All configurations verified end-to-end on canadacentral (Foundry project wujia-aifproject260512):

#	Runtime	Package Mode	Deploy	Invoke	Notes
1	dotnet_9	remote_build	PASS (19s)	PASS (streaming SSE)	Model: gpt-5.1
2	dotnet_9	bundled	PASS	PASS	dotnet publish runs locally
3	python_3_12	remote_build	PASS	PASS	Regression check (no change)

Invoke Output Example (Remote Build, dotnet_9)

Agent:    hello-world-dotnet-invocations (remote, invocations protocol)
Input:    "What is 2+2?"
Session:  (new -- server will assign)

Invocation:   inv_ec38240e65957f5600bNhzDBxxuw7IHJf7bxYXDxdsJZqtnDJW
Session:  8e0044805feaa1c000rE03tPFMgIHo0GrGeLFbQEE52lx8hrLX (assigned by server)
[hello-world-dotnet-invocations] {"type":"token","content":"2"}
{"type":"token","content":" +"}
{"type":"token","content":" 2"}
{"type":"token","content":" ="}
{"type":"token","content":" 4"}
{"type":"token","content":"."}
{"type":"done","full_text":"2 + 2 = 4."}

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Unit Tests

ok  azureaiagent/internal/cmd              14.084s
ok  azureaiagent/internal/pkg/agents/agent_api    21.724s
ok  azureaiagent/internal/pkg/agents/agent_yaml    5.329s
ok  azureaiagent/internal/project           5.604s

Specific test coverage for this PR:

• TestDetectDefaultEntryPoint -- verifies .dll detection from dotnet publish output and .csproj AssemblyName fallback
• TestCodeConfigurationDotnetRoundTrip -- verifies dotnet_9 runtime maps to API format with ["dotnet", "HelloWorld.dll"] entry point
• TestCodeConfigurationDotnetRemoteBuild -- verifies dependency_resolution: remote_build mapping for dotnet

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Notes

• No impact on Python code deploy: All Python paths are unchanged. Runtime filtering only affects the prompt UI.
• No impact on container deploy: Container paths remain completely untouched.
• --no-prompt defaults: For .NET projects, defaults to dotnet_9 runtime. For Python projects, defaults to python_3_12 (unchanged).
• Entry point auto-detection: Looks for .csproj <AssemblyName> property first, falls back to project directory name + .dll.
• gosec G204 suppressed: exec.Command("dotnet", "publish", csprojPath, ...) -- csprojPath is derived from user's local project directory, not external input.
• 250 MB limit: ZIP packages exceeding 250 MB are rejected with a clear error before upload.
• Supported regions: Same as Python code deploy -- westus2, canadacentral, northcentralus.

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Dependencies

• Requires Feature/code deploy zip upload #8146 to merge first (this PR is rebased on top of it)
• After Feature/code deploy zip upload #8146 merges to main, this PR's diff will shrink to only the .NET-specific additions (~5 commits)

Related

• Parent PR: Feature/code deploy zip upload #8146 (code deploy ZIP upload -- Python)
• Schema: microsoft/AgentSchema#96 -- code_configuration schema updated with .NET runtimes (dotnet_8/9/10), .dll entry point examples, and .NET build workflow descriptions