.NET: Add AgentSessionStore.DeleteSessionAsync to the Abstraction by marcominerva · Pull Request #8801 · microsoft/agent-framework

Marco Minerva (marcominerva) · 2026-09-28T15:36:27Z

Bring session deletion operation to the shared AgentSessionStore abstract contract, so specialized stores also share a complete set of lifecycle methods. It was not initially considered when the abstractions moved to Agents.AI.Abstractions (#7991).

API and Abstraction Changes:

Added the abstract method DeleteSessionAsync to the AgentSessionStore base class, requiring all implementations to provide a way to delete sessions. The method is documented to treat missing sessions as a no-op. [1] [2]
Updated the public API files for all supported .NET targets to include the new DeleteSessionAsync method.

Implementation Updates:

Implemented DeleteSessionAsync in all major agent session store classes, including FileSystemAgentSessionStore, FoundryAgentSessionStore, InMemoryAgentSessionStore (both Foundry and Local), AzureBlobAgentSessionStore, IsolationKeyScopedAgentSessionStore, and NoopAgentSessionStore. Each implementation ensures deletion is idempotent and handles resource-specific details. [1] [2] [3] [4] [5] [6] [7]

Documentation Updates:

Updated the architectural decision record and specification documents to describe the new deletion capability, its contract, and its impact on implementers and consumers. [1] [2] [3] [4]
Clarified documentation for DelegatingAgentSessionStore to note that delete operations are now forwarded to the inner store by default.

Fixes #8586

Bring session deletion back to the shared AgentSessionStore contract, so the store handles a session's whole lifecycle again. It was removed when the abstraction moved to Agents.AI.Abstractions (microsoft#7991). [PREVIEW BREAKING] DeleteSessionAsync is abstract: custom stores must implement it. - In-box stores implement it; deleting a missing session is a no-op - Decorators forward it, adding the isolation partition when needed - Update PublicAPI.Unshipped.txt, unit tests, ADR-0039 and spec 003 Fixes microsoft#8586

Copilot

Copilot review overview

🟡 Changes recommended

Filesystem deletion can silently succeed without deleting an inaccessible stored session, and Foundry in-memory deletion lacks direct coverage.

Review effort: Balanced
Findings: 1 · 1

Open (2)

Delete sessions directly without a File.Exists precheck · New
Add tests for Foundry store deletion and missing-session behavior · New

What changed in this PR

Restores session deletion to the shared .NET AgentSessionStore lifecycle contract and implements it across built-in stores.

Changes:

Adds DeleteSessionAsync to the abstraction and API baselines.
Implements idempotent deletion across storage backends and decorators.
Updates tests, specifications, and ADR documentation.

File	Description
`dotnet/tests/Microsoft.Agents.AI.UnitTests/DelegatingAgentSessionStoreTests.cs`	Tests delete delegation.
`dotnet/tests/Microsoft.Agents.AI.Hosting.UnitTests/IsolationKeyScopedAgentSessionStoreTests.cs`	Tests isolation-scoped deletion.
`dotnet/tests/Microsoft.Agents.AI.Hosting.UnitTests/InMemoryAgentSessionStoreTests.cs`	Tests local and no-op deletion.
`dotnet/tests/Microsoft.Agents.AI.Hosting.OpenAI.UnitTests/ResponseSessionRegressionTests.cs`	Updates test store implementation.
`dotnet/tests/Microsoft.Agents.AI.Hosting.AzureStorage.UnitTests/AzureBlobAgentSessionStoreTests.cs`	Tests blob deletion.
`dotnet/tests/Microsoft.Agents.AI.Foundry.Hosting.UnitTests/ResilientTwoLifetimeIntegrationTests.cs`	Forwards deletion in test store.
`dotnet/tests/Microsoft.Agents.AI.Foundry.Hosting.UnitTests/FoundryAgentSessionStoreTests.cs`	Tests Foundry deletion.
`dotnet/tests/Microsoft.Agents.AI.Foundry.Hosting.UnitTests/FileSystemAgentSessionStoreTests.cs`	Tests filesystem deletion.
`dotnet/tests/Microsoft.Agents.AI.Foundry.Hosting.UnitTests/AgentFrameworkResponseHandlerResilienceTests.cs`	Updates test implementations.
`dotnet/tests/Microsoft.Agents.AI.Abstractions.UnitTests/AgentSessionStoreTests.cs`	Updates abstraction test store.
`dotnet/src/Microsoft.Agents.AI/PublicAPI/netstandard2.0/PublicAPI.Unshipped.txt`	Records delegating API.
`dotnet/src/Microsoft.Agents.AI/PublicAPI/net9.0/PublicAPI.Unshipped.txt`	Records delegating API.
`dotnet/src/Microsoft.Agents.AI/PublicAPI/net8.0/PublicAPI.Unshipped.txt`	Records delegating API.
`dotnet/src/Microsoft.Agents.AI/PublicAPI/net472/PublicAPI.Unshipped.txt`	Records delegating API.
`dotnet/src/Microsoft.Agents.AI/PublicAPI/net10.0/PublicAPI.Unshipped.txt`	Records delegating API.
`dotnet/src/Microsoft.Agents.AI/DelegatingAgentSessionStore.cs`	Forwards delete operations.
`dotnet/src/Microsoft.Agents.AI.Hosting/NoopAgentSessionStore.cs`	Adds no-op deletion.
`dotnet/src/Microsoft.Agents.AI.Hosting/Local/InMemoryAgentSessionStore.cs`	Adds local-memory deletion.
`dotnet/src/Microsoft.Agents.AI.Hosting/IsolationKeyScopedAgentSessionStore.cs`	Applies isolation to deletion.
`dotnet/src/Microsoft.Agents.AI.Hosting.AzureStorage/Blob/AzureBlobAgentSessionStore.cs`	Deletes session blobs.
`dotnet/src/Microsoft.Agents.AI.Foundry.Hosting/InMemoryAgentSessionStore.cs`	Adds Foundry-memory deletion.
`dotnet/src/Microsoft.Agents.AI.Foundry.Hosting/FoundryAgentSessionStore.cs`	Deletes Foundry state items.
`dotnet/src/Microsoft.Agents.AI.Foundry.Hosting/FileSystemAgentSessionStore.cs`	Deletes session files.
`dotnet/src/Microsoft.Agents.AI.Abstractions/PublicAPI/netstandard2.0/PublicAPI.Unshipped.txt`	Records shared API.
`dotnet/src/Microsoft.Agents.AI.Abstractions/PublicAPI/net9.0/PublicAPI.Unshipped.txt`	Records shared API.
`dotnet/src/Microsoft.Agents.AI.Abstractions/PublicAPI/net8.0/PublicAPI.Unshipped.txt`	Records shared API.
`dotnet/src/Microsoft.Agents.AI.Abstractions/PublicAPI/net472/PublicAPI.Unshipped.txt`	Records shared API.
`dotnet/src/Microsoft.Agents.AI.Abstractions/PublicAPI/net10.0/PublicAPI.Unshipped.txt`	Records shared API.
`dotnet/src/Microsoft.Agents.AI.Abstractions/AgentSessionStore.cs`	Defines deletion contract.
`docs/specs/003-dotnet-hosting-protocol-helpers.md`	Documents deletion behavior.
`docs/decisions/0039-shared-agent-session-store.md`	Updates lifecycle decision.

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- FileSystemAgentSessionStore: delete without a File.Exists precheck so access and I/O failures surface; a missing agent directory stays a no-op. - Add unit tests for the Foundry InMemoryAgentSessionStore delete path.

Roger Barreto (rogerbarreto) · 2026-09-29T10:26:17Z

+        catch (DirectoryNotFoundException)
+        {
+            // No directory for this agent means nothing was ever stored.
+        }


Check if the directory exists instead of relying in the exception to ignore it.

Roger Barreto (rogerbarreto) · 2026-09-29T10:28:08Z

+        catch (FoundryStorageNotFoundException)
+        {
+            // Nothing stored for this key, so deletion remains idempotent.
+        }


Exceptions that are swallowed should have a log at least, lets bring a debug level logging or similar level we already have in the repo for exceptions that are ignored.

Please also include UT validating the Logs were emitted.

Roger Barreto (rogerbarreto) · 2026-09-29T10:31:55Z

+        catch (RequestFailedException ex) when (ex.ErrorCode == BlobErrorCode.ContainerNotFound.ToString())
+        {
+            // A missing container cannot contain the requested session, so deletion remains idempotent.
+        }


Similar as the other comment, please log the exception swelling when the container is not found, is this the only server error that could be gracefully handled?

Roger Barreto (rogerbarreto) · 2026-09-29T10:33:06Z

+        ArgumentNullException.ThrowIfNull(agent);
+        ArgumentNullException.ThrowIfNull(key);


nit, for consistency (check any other change on this PR)

Suggested change

ArgumentNullException.ThrowIfNull(agent);

ArgumentNullException.ThrowIfNull(key);

_ = Throw.IfNull(agent);

_ = Throw.IfNull(key);

Roger Barreto (rogerbarreto)

Overall LGTM, some comments

Roger Barreto (rogerbarreto) · 2026-09-29T10:35:37Z

+        catch (FoundryStorageNotFoundException)
+        {
+            // Nothing stored for this key, so deletion remains idempotent.
+        }


Please also include UT validating the Logs were emitted.

Copilot AI balanced review requested due to automatic review settings September 28, 2026 15:36

Marco Minerva (marcominerva) deployed to github-app-auth September 28, 2026 15:36 — with GitHub Actions Active

agent-framework-automation Bot added documentation Usage: [Issues, PRs], Target: documentation in the code base and learn docs .NET Usage: [Issues, PRs], Target: .Net labels Sep 28, 2026

Marco Minerva (marcominerva) deployed to github-app-auth September 28, 2026 15:37 — with GitHub Actions Active

Copilot started reviewing on behalf of Marco Minerva (marcominerva) September 28, 2026 15:37 View session

Marco Minerva (marcominerva) mentioned this pull request Sep 28, 2026

.NET: Why has DeleteSessionAsync been removed from AgentSessionStore? #8586

Open

Copilot AI reviewed Sep 28, 2026

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Comment thread dotnet/src/Microsoft.Agents.AI.Foundry.Hosting/FileSystemAgentSessionStore.cs

Comment thread dotnet/src/Microsoft.Agents.AI.Foundry.Hosting/InMemoryAgentSessionStore.cs

.NET: Address session store delete review

3115387

- FileSystemAgentSessionStore: delete without a File.Exists precheck so access and I/O failures surface; a missing agent directory stays a no-op. - Add unit tests for the Foundry InMemoryAgentSessionStore delete path.

Marco Minerva (marcominerva) deployed to github-app-auth September 28, 2026 16:46 — with GitHub Actions Active

westey (westey-m) assigned Roger Barreto (rogerbarreto) Sep 28, 2026

Merge branch 'main' into dotnet-readd-session-store-delete

c40748f

Roger Barreto (rogerbarreto) deployed to github-app-auth September 29, 2026 09:32 — with GitHub Actions Active

Roger Barreto (rogerbarreto) deployed to integration September 29, 2026 09:32 — with GitHub Actions Active

Roger Barreto (rogerbarreto) reviewed Sep 29, 2026

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Roger Barreto (rogerbarreto) approved these changes Sep 29, 2026

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Roger Barreto (rogerbarreto) changed the title ~~.NET: Re-add AgentSessionStore.DeleteSessionAsync~~ .NET: Add AgentSessionStore.DeleteSessionAsync to the Abstraction Sep 29, 2026

Roger Barreto (rogerbarreto) deployed to github-app-auth September 29, 2026 10:38 — with GitHub Actions Active

Roger Barreto (rogerbarreto) deployed to github-app-auth September 29, 2026 10:39 — with GitHub Actions Active

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.NET: Add AgentSessionStore.DeleteSessionAsync to the Abstraction - #8801

.NET: Add AgentSessionStore.DeleteSessionAsync to the Abstraction#8801
Marco Minerva (marcominerva) wants to merge 3 commits into
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Marco Minerva (marcominerva) commented Sep 28, 2026 •

edited by rogerbarreto

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		ArgumentNullException.ThrowIfNull(agent);
		ArgumentNullException.ThrowIfNull(key);

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Marco Minerva (marcominerva) commented Sep 28, 2026 • edited by rogerbarreto Loading Uh oh! There was an error while loading. Please reload this page.

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Marco Minerva (marcominerva) commented Sep 28, 2026 •

edited by rogerbarreto

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