Skip to content

Drop the duplicated trailing user turn in Foundation Models sessions #217

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
mattt merged 2 commits into from
Sep 4, 2026
Merged

Drop the duplicated trailing user turn in Foundation Models sessions #217

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
e9a611d
Drop the duplicated trailing user turn in Foundation Models sessions
james-333i Sep 4, 2026
6b968f7
Fix formatting for swift-format lint
mattt Sep 4, 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
19 changes: 17 additions & 2 deletions Sources/AnyLanguageModel/Models/SystemLanguageModel.swift
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -78,7 +78,7 @@
let fmSession = FoundationModels.LanguageModelSession(
model: systemModel,
tools: session.tools.toFoundationModels(),
transcript: session.transcript.toFoundationModels(
transcript: fmTranscriptDroppingDuplicatePrompt(session.transcript, prompt: prompt).toFoundationModels(
instructions: session.instructions,
toolDefinitions: session.tools
.filter(\.includesSchemaInInstructions)
Expand Down Expand Up @@ -159,7 +159,7 @@
let fmSession = FoundationModels.LanguageModelSession(
model: systemModel,
tools: session.tools.toFoundationModels(),
transcript: session.transcript.toFoundationModels(
transcript: fmTranscriptDroppingDuplicatePrompt(session.transcript, prompt: prompt).toFoundationModels(
instructions: session.instructions,
toolDefinitions: session.tools
.filter(\.includesSchemaInInstructions)
Expand Down Expand Up @@ -367,6 +367,21 @@

// MARK: - Helpers

@available(macOS 26.0, iOS 26.0, watchOS 26.0, tvOS 26.0, visionOS 26.0, *)
func fmTranscriptDroppingDuplicatePrompt(_ transcript: Transcript, prompt: Prompt) -> Transcript {
guard let lastEntry = transcript.last, case .prompt(let lastPrompt) = lastEntry else {
return transcript
}
let lastText = lastPrompt.segments.compactMap { segment -> String? in
if case .text(let textSegment) = segment { return textSegment.content }
return nil
}.joined()
guard lastText == prompt.description else {
return transcript
}
return Transcript(entries: transcript.dropLast())
}

@available(macOS 26.0, iOS 26.0, watchOS 26.0, tvOS 26.0, visionOS 26.0, *)
extension Prompt {
fileprivate func toFoundationModels() -> FoundationModels.Prompt {
Expand Down