fix: compaction fallback to lowest model context limit

pkg/modelsdev/store.go

@@ -3,6 +3,7 @@ package modelsdev
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"log/slog"
@@ -23,6 +24,9 @@ const (
 	refreshInterval = 24 * time.Hour
 )
 
+// ErrProviderNotFound is returned when a requested provider is not found in the database.
+var ErrProviderNotFound = errors.New("provider not found")
+
 // Store manages access to the models.dev data.
 // All methods are safe for concurrent use.
 //
@@ -91,7 +95,7 @@ func (s *Store) getProvider(ctx context.Context, providerID string) (*Provider,
 
 	provider, exists := db.Providers[providerID]
 	if !exists {
-		return nil, fmt.Errorf("provider %q not found", providerID)
+		return nil, fmt.Errorf("%w: %q", ErrProviderNotFound, providerID)
 	}
 
 	return &provider, nil

pkg/runtime/session_compaction.go

@@ -11,6 +11,7 @@ import (
 	"github.com/docker/docker-agent/pkg/compaction"
 	"github.com/docker/docker-agent/pkg/model/provider"
 	"github.com/docker/docker-agent/pkg/model/provider/options"
+	"github.com/docker/docker-agent/pkg/modelsdev"
 	"github.com/docker/docker-agent/pkg/session"
 	"github.com/docker/docker-agent/pkg/team"
 )
@@ -26,7 +27,9 @@ const maxKeepTokens = 20_000
 // persistence, token count updates). The agent is used to extract the
 // conversation from the session and to obtain the model for summarization.
 func (r *LocalRuntime) doCompact(ctx context.Context, sess *session.Session, a *agent.Agent, additionalPrompt string, events chan Event) {
-	slog.Debug("Generating summary for session", "session_id", sess.ID)
+	lg := slog.With("session_id", sess.ID, "agent", a.Name(), "action", "compaction")
+
+	lg.Debug("Generating summary for session")
 	events <- SessionCompaction(sess.ID, "started", a.Name())
 	defer func() {
 		events <- SessionCompaction(sess.ID, "completed", a.Name())
@@ -37,10 +40,32 @@ func (r *LocalRuntime) doCompact(ctx context.Context, sess *session.Session, a *
 		options.WithStructuredOutput(nil),
 		options.WithMaxTokens(maxSummaryTokens),
 	)
+
 	m, err := r.modelsStore.GetModel(ctx, summaryModel.ID())
+	if err != nil && errors.Is(err, modelsdev.ErrProviderNotFound) {
+		lg.Debug("Provider not found; attempting to find by model name", "error", err)
+
+		db, dberr := r.modelsStore.GetDatabase(ctx)
+		if dberr != nil {
+			lg.Error("Provider not found and failed to find by model name", "error", dberr)
+			events <- Error("Failed to get db to find model definition: " + dberr.Error())
+			return
+		}
+
+		// Find the lowest context limit for this model, regardless of the provider.
+		for _, provider := range db.Providers {
+			if v, ok := provider.Models[summaryModel.BaseConfig().ModelConfig.Model]; ok {
+				if m == nil || v.Limit.Context < m.Limit.Context {
+					m = &v
+					err = nil
+				}
+			}
+		}
+	}
+
 	if err != nil {
-		slog.Error("Failed to generate session summary", "error", errors.New("failed to get model definition"))
-		events <- Error("Failed to get model definition")
+		lg.Error("Failed to get model definition to generate session summary", "error", err)
+		events <- Error("Failed to get model definition: " + err.Error())
 		return
 	}
 
@@ -58,12 +83,12 @@ func (r *LocalRuntime) doCompact(ctx context.Context, sess *session.Session, a *
 	t := team.New(team.WithAgents(compactionAgent))
 	rt, err := New(t, WithSessionCompaction(false))
 	if err != nil {
-		slog.Error("Failed to generate session summary", "error", err)
+		lg.Error("Failed to generate session summary", "error", err)
 		events <- Error(err.Error())
 		return
 	}
 	if _, err = rt.Run(ctx, compactionSession); err != nil {
-		slog.Error("Failed to generate session summary", "error", err)
+		lg.Error("Failed to generate session summary", "error", err)
 		events <- Error(err.Error())
 		return
 	}
@@ -83,7 +108,7 @@ func (r *LocalRuntime) doCompact(ctx context.Context, sess *session.Session, a *
 	})
 	_ = r.sessionStore.UpdateSession(ctx, sess)
 
-	slog.Debug("Generated session summary", "session_id", sess.ID, "summary_length", len(summary))
+	lg.Debug("Generated session summary", "summary_length", len(summary))
 	events <- SessionSummary(sess.ID, summary, a.Name(), firstKeptEntry)
 }