Skip to content

.NET: Replace inline string literals with constants in ChatHistoryMemoryProvider #4096

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
westey-m merged 2 commits into from
Feb 20, 2026
+39 −27
Merged

.NET: Replace inline string literals with constants in ChatHistoryMemoryProvider #4096

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
b1d29ad
Replace inline string literals with constants in ChatHistoryMemoryPro…
westey-m Feb 19, 2026
9e4f0b0
Merge branch 'main' into fix/chat-history-memory-string-consts
westey-m Feb 19, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
66 changes: 39 additions & 27 deletions dotnet/src/Microsoft.Agents.AI/Memory/ChatHistoryMemoryProvider.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -41,6 +41,18 @@ public sealed class ChatHistoryMemoryProvider : AIContextProvider, IDisposable
private const string DefaultFunctionToolName = "Search";
private const string DefaultFunctionToolDescription = "Allows searching for related previous chat history to help answer the user question.";

private const string KeyField = "Key";
private const string RoleField = "Role";
private const string MessageIdField = "MessageId";
private const string AuthorNameField = "AuthorName";
private const string ApplicationIdField = "ApplicationId";
private const string AgentIdField = "AgentId";
private const string UserIdField = "UserId";
private const string SessionIdField = "SessionId";
private const string ContentField = "Content";
private const string CreatedAtField = "CreatedAt";
private const string ContentEmbeddingField = "ContentEmbedding";

private readonly ProviderSessionState<State> _sessionState;

#pragma warning disable CA2213 // VectorStore is not owned by this class - caller is responsible for disposal
Expand Down Expand Up @@ -98,17 +110,17 @@ public ChatHistoryMemoryProvider(
{
Properties =
[
new VectorStoreKeyProperty("Key", typeof(Guid)),
new VectorStoreDataProperty("Role", typeof(string)) { IsIndexed = true },
new VectorStoreDataProperty("MessageId", typeof(string)) { IsIndexed = true },
new VectorStoreDataProperty("AuthorName", typeof(string)),
new VectorStoreDataProperty("ApplicationId", typeof(string)) { IsIndexed = true },
new VectorStoreDataProperty("AgentId", typeof(string)) { IsIndexed = true },
new VectorStoreDataProperty("UserId", typeof(string)) { IsIndexed = true },
new VectorStoreDataProperty("SessionId", typeof(string)) { IsIndexed = true },
new VectorStoreDataProperty("Content", typeof(string)) { IsFullTextIndexed = true },
new VectorStoreDataProperty("CreatedAt", typeof(string)) { IsIndexed = true },
new VectorStoreVectorProperty("ContentEmbedding", typeof(string), Throw.IfLessThan(vectorDimensions, 1))
new VectorStoreKeyProperty(KeyField, typeof(Guid)),
new VectorStoreDataProperty(RoleField, typeof(string)) { IsIndexed = true },
new VectorStoreDataProperty(MessageIdField, typeof(string)) { IsIndexed = true },
new VectorStoreDataProperty(AuthorNameField, typeof(string)),
new VectorStoreDataProperty(ApplicationIdField, typeof(string)) { IsIndexed = true },
new VectorStoreDataProperty(AgentIdField, typeof(string)) { IsIndexed = true },
new VectorStoreDataProperty(UserIdField, typeof(string)) { IsIndexed = true },
new VectorStoreDataProperty(SessionIdField, typeof(string)) { IsIndexed = true },
new VectorStoreDataProperty(ContentField, typeof(string)) { IsFullTextIndexed = true },
new VectorStoreDataProperty(CreatedAtField, typeof(string)) { IsIndexed = true },
new VectorStoreVectorProperty(ContentEmbeddingField, typeof(string), Throw.IfLessThan(vectorDimensions, 1))
]
};

Expand Down Expand Up @@ -207,17 +219,17 @@ protected override async ValueTask StoreAIContextAsync(InvokedContext context, C
.Concat(context.ResponseMessages ?? [])
.Select(message => new Dictionary<string, object?>
{
["Key"] = Guid.NewGuid(),
["Role"] = message.Role.ToString(),
["MessageId"] = message.MessageId,
["AuthorName"] = message.AuthorName,
["ApplicationId"] = storageScope.ApplicationId,
["AgentId"] = storageScope.AgentId,
["UserId"] = storageScope.UserId,
["SessionId"] = storageScope.SessionId,
["Content"] = message.Text,
["CreatedAt"] = message.CreatedAt?.ToString("O") ?? DateTimeOffset.UtcNow.ToString("O"),
["ContentEmbedding"] = message.Text,
[KeyField] = Guid.NewGuid(),
[RoleField] = message.Role.ToString(),
[MessageIdField] = message.MessageId,
[AuthorNameField] = message.AuthorName,
[ApplicationIdField] = storageScope.ApplicationId,
[AgentIdField] = storageScope.AgentId,
[UserIdField] = storageScope.UserId,
[SessionIdField] = storageScope.SessionId,
[ContentField] = message.Text,
[CreatedAtField] = message.CreatedAt?.ToString("O") ?? DateTimeOffset.UtcNow.ToString("O"),
[ContentEmbeddingField] = message.Text,
})
.ToList();

Expand Down Expand Up @@ -262,7 +274,7 @@ private async Task<string> SearchTextAsync(string userQuestion, ChatHistoryMemor
}

// Format the results as a single context message
var outputResultsText = string.Join("\n", results.Select(x => (string?)x["Content"]).Where(c => !string.IsNullOrWhiteSpace(c)));
var outputResultsText = string.Join("\n", results.Select(x => (string?)x[ContentField]).Where(c => !string.IsNullOrWhiteSpace(c)));
if (string.IsNullOrWhiteSpace(outputResultsText))
{
return string.Empty;
Expand Down Expand Up @@ -314,28 +326,28 @@ private async Task<string> SearchTextAsync(string userQuestion, ChatHistoryMemor
Expression<Func<Dictionary<string, object?>, bool>>? filter = null;
if (applicationId != null)
{
filter = x => (string?)x["ApplicationId"] == applicationId;
filter = x => (string?)x[ApplicationIdField] == applicationId;
}

if (agentId != null)
{
Expression<Func<Dictionary<string, object?>, bool>> agentIdFilter = x => (string?)x["AgentId"] == agentId;
Expression<Func<Dictionary<string, object?>, bool>> agentIdFilter = x => (string?)x[AgentIdField] == agentId;
filter = filter == null ? agentIdFilter : Expression.Lambda<Func<Dictionary<string, object?>, bool>>(
Expression.AndAlso(filter.Body, agentIdFilter.Body),
filter.Parameters);
}

if (userId != null)
{
Expression<Func<Dictionary<string, object?>, bool>> userIdFilter = x => (string?)x["UserId"] == userId;
Expression<Func<Dictionary<string, object?>, bool>> userIdFilter = x => (string?)x[UserIdField] == userId;
filter = filter == null ? userIdFilter : Expression.Lambda<Func<Dictionary<string, object?>, bool>>(
Expression.AndAlso(filter.Body, userIdFilter.Body),
filter.Parameters);
}

if (sessionId != null)
{
Expression<Func<Dictionary<string, object?>, bool>> sessionIdFilter = x => (string?)x["SessionId"] == sessionId;
Expression<Func<Dictionary<string, object?>, bool>> sessionIdFilter = x => (string?)x[SessionIdField] == sessionId;
filter = filter == null ? sessionIdFilter : Expression.Lambda<Func<Dictionary<string, object?>, bool>>(
Expression.AndAlso(filter.Body, sessionIdFilter.Body),
filter.Parameters);
Expand Down
Loading