PythonAppHost Code Generator by annatisch · Pull Request #13947 · microsoft/aspire

annatisch · 2026-01-15T22:37:04Z

No description provided.

github-actions · 2026-01-15T22:37:14Z

🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://raw.githubusercontent.com/microsoft/aspire/main/eng/scripts/get-aspire-cli-pr.sh | bash -s -- 13947

Or

Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/microsoft/aspire/main/eng/scripts/get-aspire-cli-pr.ps1) } 13947"

annatisch · 2026-01-22T20:54:33Z

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Pull request overview

This is a work-in-progress PR that adds Python language support to Aspire's AppHost code generation system. It introduces a complete Python code generator with transport layer, base classes, and scaffolding support, along with necessary infrastructure changes to the CLI and type scanning system.

Changes:

Added Python language support infrastructure (PythonLanguageSupport, PythonModuleBuilder) with scaffolding, detection, and runtime configuration for Python AppHosts
Enhanced ATS capability scanner to track complete type hierarchies including implemented interfaces and base types, improving code generation accuracy
Removed async callback exports (withEnvironmentCallbackAsync, withArgsCallbackAsync, withUrlsCallbackAsync) from ResourceBuilderExtensions to simplify the API surface
Updated CLI to support Python with custom generated folder name ("aspyre") and pass-through of debug flags and additional command-line arguments
Added comprehensive Python transport layer (_transport.py) and base classes (_base.py) with 1,300+ lines of implementation
Updated test snapshots to reflect new type hierarchy information in generated TypeScript code

Reviewed changes

Copilot reviewed 26 out of 26 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
tests/Aspire.Hosting.CodeGeneration.TypeScript.Tests/Snapshots/*.verified.txt	Updated test snapshots with ImplementedInterfaces and BaseType hierarchy information
tests/Aspire.Hosting.CodeGeneration.TypeScript.Tests/Snapshots/TwoPassScanningGeneratedAspire.verified.ts	Removed async callback methods from generated TypeScript
tests/Aspire.Cli.Tests/Projects/DefaultLanguageDiscoveryTests.cs	Changed test case from "apphost.py" to "script.py" since apphost.py is now valid
src/Aspire.Hosting/ResourceBuilderExtensions.cs	Removed [AspireExport] attributes for async callback overloads
src/Aspire.Hosting/Ats/AtsCapabilityScanner.cs	Added CreateHandleTypeRef helper and enhanced type hierarchy collection
src/Aspire.Hosting/Ats/AtsCapabilityInfo.cs	Added ImplementedInterfaces and BaseType properties to AtsTypeRef
src/Aspire.Hosting/Aspire.Hosting.csproj	Added InternalsVisibleTo for Python code generation assemblies
src/Aspire.Hosting.RemoteHost/CodeGeneration/CodeGenerationService.cs	Removed blank line (whitespace cleanup)
src/Aspire.Hosting.CodeGeneration.Python/*	Added complete Python code generator implementation (3 new files)
src/Aspire.Cli/Projects/*	Updated CLI infrastructure to support Python with custom folder names and argument passing

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Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Exclude Azure.Sql, Foundry, and Maui from Python polyglot playground validation until Python code generation supports their current API surface. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Sanitize Python identifiers derived from capability parameters and derive generic Python type names without leaking CLR assembly metadata so the Python playground validation can cover Azure.Sql, Foundry, and Maui again. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Remove the stale .modules sys.path bootstrap from the generated Python playground ValidationAppHosts so they match the shared Python scaffold, and add a regression test to keep new scaffolds importing aspire_app directly. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Drop the implementation-shaped Python scaffold test and rely on the existing generated-output verification for this area. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Create a Python AppHost playground that orchestrates a Redis cache, a Uvicorn-hosted Python app, and a Vite frontend that references the Python service. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

github-actions · 2026-03-25T15:47:58Z

Re-running the failed jobs in the CI workflow for this pull request because 1 job was identified as retry-safe transient failures in the CI run attempt.
GitHub was asked to rerun all failed jobs for that attempt, and the rerun is being tracked in the rerun attempt.
The job links below point to the failed attempt jobs that matched the retry-safe transient failure rules.

Tests / Azure.AI.OpenAI / Azure.AI.OpenAI (windows-latest) - Post-test cleanup steps 'Upload logs, and test results | Copy CLI E2E recordings for upload | Upload CLI E2E recordings | Generate test results summary | Post Checkout code' matched the Windows process initialization failure override allowlist.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

github-actions · 2026-03-26T03:11:36Z

Re-running the failed jobs in the CI workflow for this pull request because 2 jobs were identified as retry-safe transient failures in the CI run attempt.
GitHub was asked to rerun all failed jobs for that attempt, and the rerun is being tracked in the rerun attempt.
The job links below point to the failed attempt jobs that matched the retry-safe transient failure rules.

Tests / Hosting.CodeGeneration.Python / Hosting.CodeGeneration.Python (ubuntu-latest) - Failed step 'Checkout code' matched the transient annotation allowlist.
Tests / Hosting-5 / Hosting-5 (windows-latest) - Job-level runner or infrastructure failure matched the transient allowlist.

github-actions · 2026-03-26T03:21:32Z

🎬 CLI E2E Test Recordings — 52 recordings uploaded (commit fd23cdc)

View recordings

Test	Recording
AddPackageInteractiveWhileAppHostRunningDetached	▶️ View Recording
AddPackageWhileAppHostRunningDetached	▶️ View Recording
AgentCommands_AllHelpOutputs_AreCorrect	▶️ View Recording
AgentInitCommand_DefaultSelection_InstallsSkillOnly	▶️ View Recording
AgentInitCommand_MigratesDeprecatedConfig	▶️ View Recording
AspireAddPackageVersionToDirectoryPackagesProps	▶️ View Recording
AspireUpdateRemovesAppHostPackageVersionFromDirectoryPackagesProps	▶️ View Recording
Banner_DisplayedOnFirstRun	▶️ View Recording
Banner_DisplayedWithExplicitFlag	▶️ View Recording
Banner_NotDisplayedWithNoLogoFlag	▶️ View Recording
CertificatesClean_RemovesCertificates	▶️ View Recording
CertificatesTrust_WithNoCert_CreatesAndTrustsCertificate	▶️ View Recording
CertificatesTrust_WithUntrustedCert_TrustsCertificate	▶️ View Recording
ConfigSetGet_CreatesNestedJsonFormat	▶️ View Recording
CreateAndRunAspireStarterProject	▶️ View Recording
CreateAndRunAspireStarterProjectWithBundle	▶️ View Recording
CreateAndRunEmptyAppHostProject	▶️ View Recording
CreateAndRunJavaEmptyAppHostProject	▶️ View Recording
CreateAndRunJsReactProject	▶️ View Recording
CreateAndRunPythonReactProject	▶️ View Recording
CreateAndRunTypeScriptEmptyAppHostProject	▶️ View Recording
CreateAndRunTypeScriptStarterProject	▶️ View Recording
CreateJavaAppHostWithViteApp	▶️ View Recording
CreateStartAndStopAspireProject	▶️ View Recording
CreateTypeScriptAppHostWithViteApp	▶️ View Recording
DescribeCommandResolvesReplicaNames	▶️ View Recording
DescribeCommandShowsRunningResources	▶️ View Recording
DetachFormatJsonProducesValidJson	▶️ View Recording
DoctorCommand_DetectsDeprecatedAgentConfig	▶️ View Recording
DoctorCommand_WithSslCertDir_ShowsTrusted	▶️ View Recording
DoctorCommand_WithoutSslCertDir_ShowsPartiallyTrusted	▶️ View Recording
GlobalMigration_HandlesCommentsAndTrailingCommas	▶️ View Recording
GlobalMigration_HandlesMalformedLegacyJson	▶️ View Recording
GlobalMigration_PreservesAllValueTypes	▶️ View Recording
GlobalMigration_SkipsWhenNewConfigExists	▶️ View Recording
GlobalSettings_MigratedFromLegacyFormat	▶️ View Recording
InvalidAppHostPathWithComments_IsHealedOnRun	▶️ View Recording
LogsCommandShowsResourceLogs	▶️ View Recording
PsCommandListsRunningAppHost	▶️ View Recording
PsFormatJsonOutputsOnlyJsonToStdout	▶️ View Recording
PublishWithDockerComposeServiceCallbackSucceeds	▶️ View Recording
RestoreGeneratesSdkFiles	▶️ View Recording
RunWithMissingAwaitShowsHelpfulError	▶️ View Recording
SecretCrudOnDotNetAppHost	▶️ View Recording
SecretCrudOnTypeScriptAppHost	▶️ View Recording
StagingChannel_ConfigureAndVerifySettings_ThenSwitchChannels	▶️ View Recording
StopAllAppHostsFromAppHostDirectory	▶️ View Recording
StopAllAppHostsFromUnrelatedDirectory	▶️ View Recording
StopNonInteractiveMultipleAppHostsShowsError	▶️ View Recording
StopNonInteractiveSingleAppHost	▶️ View Recording
StopWithNoRunningAppHostExitsSuccessfully	▶️ View Recording
TypeScriptAppHostWithProjectReferenceIntegration	▶️ View Recording

_{📹 Recordings uploaded automatically from CI run #23569697285}

* Start porting over Python API * Merged latest changes * Update to module builder * Support recursive interface collection * Fix interfaces * Support sync and async variants * More merging * Fixed merge * Updates * Updates * Fixed generic interface * Update AspireList * Cached properties * Added resource constructors with kwargs * Fixed ABCs and list/dict registration * Fix handles and logging * Fix some tests * More test fixes * Update python lookup * Fix Python CodeGeneration build errors and update tests - Add XML documentation to AtsPythonCodeGenerator class - Remove unused 'using System.Text;' and 'using Aspire.Hosting.ApplicationModel;' directives - Update test file key from 'aspire.py' to '__init__.py' to match generator output - Update test assertions to use actual generated method names (with_env instead of with_environment) - Update verified snapshots to match new generator output * Patch files * Fix Python polyglot validation test to match scaffold output The scaffold generates 'builder.run()' but the validation test was looking for 'builder.build().run()'. Updated the grep/sed pattern to match the actual scaffold output. * Update Go, Java, and Rust CodeGeneration test snapshots Updated verified snapshots to match current scanner output after main merge. * Fix Python validation test indentation The inserted Redis code needs proper 4-space indentation to be valid inside the Python 'with' block. * Improvements to errors + rename * Regenerate snapshots * Revert fallback cast error handling * Add missing XML documentation to PythonModuleBuilder public members (microsoft#14743) * Initial plan * Add missing XML documentation to MethodParameters property and DistributedApplicationBuilder constant Co-authored-by: annatisch <8689453+annatisch@users.noreply.github.com> --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: annatisch <8689453+annatisch@users.noreply.github.com> * Add comprehensive XML documentation to PythonLanguageSupport public API (microsoft#14744) * Initial plan * Add comprehensive XML documentation to PythonLanguageSupport public members Co-authored-by: annatisch <8689453+annatisch@users.noreply.github.com> --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: annatisch <8689453+annatisch@users.noreply.github.com> * Add descriptive XML documentation for AtsTypeRef.ImplementedInterfaces and AtsTypeRef.BaseType (microsoft#14746) * Initial plan * Improve XML documentation for ImplementedInterfaces and BaseType on AtsTypeRef Co-authored-by: annatisch <8689453+annatisch@users.noreply.github.com> --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: annatisch <8689453+annatisch@users.noreply.github.com> * Re-record tests * Remove extra project reference * Re-record tests * Re-record tests * Restructure packaging * Refactored aspire module to single file * Generate to .modules * Generate modules before installing * Support conditional ref expr * Remove additionalArgs * Tests * Renames to prevent naming conflicts * Group similar overloads * Support param defaults * Update Python codegen snapshots Accept regenerated Python snapshots after the cancellation token and process timeout fixes. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Fix polyglot and CLI template validation Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Add Python polyglot playground validation Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Skip unsupported Python SDK playgrounds Exclude Azure.Sql, Foundry, and Maui from Python polyglot playground validation until Python code generation supports their current API surface. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Fix Python codegen naming conflicts Sanitize Python identifiers derived from capability parameters and derive generic Python type names without leaking CLR assembly metadata so the Python playground validation can cover Azure.Sql, Foundry, and Maui again. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Address PR review feedback Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Refresh Python playground apphosts Remove the stale .modules sys.path bootstrap from the generated Python playground ValidationAppHosts so they match the shared Python scaffold, and add a regression test to keep new scaffolds importing aspire_app directly. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Remove Python scaffold assertion test Drop the implementation-shaped Python scaffold test and rely on the existing generated-output verification for this area. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Add PythonAppHost playground Create a Python AppHost playground that orchestrates a Redis cache, a Uvicorn-hosted Python app, and a Vite frontend that references the Python service. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Update Python codegen snapshot Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Fix Java validation selection Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> * Fix describe replica test Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> --------- Co-authored-by: Sebastien Ros <sebastienros@gmail.com> Co-authored-by: Copilot <198982749+Copilot@users.noreply.github.com> Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

aspire-repo-bot · 2026-05-05T05:28:58Z

Warning

The create_pull_request operation failed: E003: Cannot create pull request with more than 100 files (received 122). The code changes were not applied.

Documentation updates have been drafted for this PR. 📝

A draft docs PR has been opened against release/13.3 on microsoft/aspire.dev (branch docs/python-apphost-13947), targeting the release/13.3 branch based on this PR's milestone.

What was documented

New page: app-host/python-apphost.mdx — Python AppHost project structure reference, covering:
- Scaffolded files: apphost.py, aspire.config.json, .modules/, pylock.apphost.toml, apphost_requirements.txt
- aspire.config.json schema with "language": "python"
- apphost.py entry-point patterns and create_builder usage
- Python toolchain detection: uv (recommended, uses pylock.apphost.toml) vs standard venv/pip fallback (uses apphost_requirements.txt)
- Step-by-step "Running the AppHost" walkthrough
Updated: languages-and-runtimes/index.mdx — Added Python row to the AppHost languages table
Updated: docs.topics.ts — Added Python entry to the sidebar "Project structure" section

The draft PR needs human review before merging. Please verify the code examples and toolchain detection details match the final implementation.

Generated by PR Documentation Check · ● 4.8M · ◷

annatisch added 5 commits January 14, 2026 16:43

Start porting over Python API

6f3ae15

Merged latest changes

b79cba7

Update to module builder

ad35541

Support recursive interface collection

0d24e91

Fix interfaces

c272f0d

annatisch added 16 commits January 16, 2026 14:49

Support sync and async variants

bd0665d

Merge branch 'main' into pythonapphost

58e4d98

More merging

b6fa52f

Fixed merge

d85a4f0

Updates

d5b9650

Merge branch 'main' into pythonapphost

d6b396a

Updates

7cd2633

Fixed generic interface

a2e00ee

Update AspireList

349c966

Cached properties

e2c2b33

Added resource constructors with kwargs

9ef48bc

Fixed ABCs and list/dict registration

8fc957b

Fix handles and logging

b0c014a

Fix some tests

0aa8e5e

Merge branch 'main' into pythonapphost

6cbc171

More test fixes

e2f3dbc

Update python lookup

2d6f9c8

annatisch marked this pull request as ready for review January 22, 2026 22:09

Copilot AI review requested due to automatic review settings January 22, 2026 22:09

Copilot started reviewing on behalf of annatisch January 22, 2026 22:09 View session

annatisch changed the title ~~[WIP] PythonAppHost Code Generator~~ PythonAppHost Code Generator Jan 22, 2026

Copilot AI reviewed Jan 22, 2026

View reviewed changes

github-actions Bot mentioned this pull request Jan 23, 2026

[pull requests] Review required #13834

Closed

sebastienros requested a review from eerhardt as a code owner March 24, 2026 17:14

sebastienros and others added 3 commits March 24, 2026 13:43

Add Python polyglot playground validation

32443bc

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Skip unsupported Python SDK playgrounds

997ea4d

Exclude Azure.Sql, Foundry, and Maui from Python polyglot playground validation until Python code generation supports their current API surface. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

annatisch commented Mar 24, 2026

View reviewed changes

Comment thread playground/polyglot/Python/Aspire.Hosting.Valkey/ValidationAppHost/apphost.py Outdated

sebastienros and others added 4 commits March 25, 2026 07:03

Address PR review feedback

9e340bb

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Remove Python scaffold assertion test

608143b

Drop the implementation-shaped Python scaffold test and rely on the existing generated-output verification for this area. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Add PythonAppHost playground

1efdb97

Create a Python AppHost playground that orchestrates a Redis cache, a Uvicorn-hosted Python app, and a Vite frontend that references the Python service. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

davidfowl approved these changes Mar 25, 2026

View reviewed changes

sebastienros and others added 4 commits March 25, 2026 14:24

Merge origin/main into pythonapphost

e9124c5

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Update Python codegen snapshot

cc3c815

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Merge origin/main into pythonapphost

16260dd

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Fix Java validation selection

20449be

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

eerhardt mentioned this pull request Mar 25, 2026

Move Python starter template to TypeScript AppHost and CLI template factory #15574

Merged

10 tasks

Fix describe replica test

fd23cdc

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

sebastienros merged commit a6c0b94 into main Mar 26, 2026
500 of 504 checks passed

sebastienros deleted the pythonapphost branch March 26, 2026 03:51

joperezr mentioned this pull request Apr 1, 2026

Merge release/13.2 into main after 13.2.0 release #15540

Merged

joperezr added this to the 13.3 milestone Apr 14, 2026

This was referenced Apr 24, 2026

[13.3] Change log #16452

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[13.3] Change log #16453

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[13.3] Change log #16455

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PythonAppHost Code Generator#13947

PythonAppHost Code Generator#13947
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