Add job pkg metadata

internal/job/job.go

@@ -8,6 +8,7 @@ package job
 import (
 	"context"
 	"database/sql"
+	"encoding/json/jsontext"
 	"encoding/json/v2"
 	"errors"
 	"fmt"
@@ -254,7 +255,7 @@ func (j *Job) callTool(
 		context.WithoutCancel(ctx), resultSaveTimeout,
 	)
 	defer saveCancel()
-	if _, err := j.insertMessage(saveCtx, cid, message, update); err != nil {
+	if _, err := j.insertMessage(saveCtx, cid, message, nil, update); err != nil {
 		log.ErrorContext(
 			ctx,
 			"failed to persist tool result",
@@ -370,8 +371,8 @@ func (j *Job) createConversation(
 // Cron returns the parsed cron schedule.
 func (j *Job) Cron() cron.Schedule { return j.cron }
 
-// insertMessage stores one message in a conversation, after every
-// message already stored there.
+// insertMessage stores a message and its optional inference metadata in the
+// same row at the next sequence in a conversation. Nil metadata stores NULL.
 // If executionUpdate is non-nil, its status change and the message commit in
 // the same transaction. A nil update leaves execution statuses unchanged.
 // The caller is responsible for identifying the execution and choosing a
@@ -380,12 +381,23 @@ func (j *Job) insertMessage(
 	ctx context.Context,
 	cid string,
 	message llm.Message,
+	metadata *llm.Metadata,
 	executionUpdate *db.UpdateExecutionStatusParams,
 ) (*db.Message, error) {
 	content, err := json.Marshal(message)
 	if err != nil {
 		return nil, fmt.Errorf("marshal message: %w", err)
 	}
+	var metadataJSON jsontext.Value
+	if metadata != nil {
+		encoded, err := json.Marshal(
+			metadata, json.FormatNilSliceAsNull(true),
+		)
+		if err != nil {
+			return nil, fmt.Errorf("marshal metadata: %w", err)
+		}
+		metadataJSON = jsontext.Value(encoded)
+	}
 
 	tx, err := j.db.BeginTx(ctx, nil)
 	if err != nil {
@@ -401,6 +413,7 @@ func (j *Job) insertMessage(
 	m, err := q.InsertMessage(ctx, db.InsertMessageParams{
 		Content:        string(content),
 		ConversationId: cid,
+		Metadata:       metadataJSON,
 		Role:           db.MessageRole(message.Role),
 		Sequence:       sequence,
 	})
@@ -507,7 +520,7 @@ func (j *Job) Run(ctx context.Context) Result {
 		// Persist the assistant message before acting on it,
 		// so an interruption leaves a committed record.
 		message := result.Message
-		tm, err = j.insertMessage(ctx, c.Id, message, nil)
+		tm, err = j.insertMessage(ctx, c.Id, message, &result.Metadata, nil)
 		if err != nil {
 			break
 		}

internal/job/job_test.go

@@ -450,6 +450,32 @@ func TestRunPersistsToolLoop(t *testing.T) {
 	if len(stored) != len(wantRoles) {
 		t.Fatalf("stored messages = %d, want %d", len(stored), len(wantRoles))
 	}
+	for i, message := range stored {
+		if message.Role != db.MessageRoleAssistant {
+			if message.Metadata != nil {
+				t.Errorf("message %d metadata = %v, want nil", i, message.Metadata)
+			}
+			continue
+		}
+		if message.Metadata == nil {
+			t.Fatalf("assistant %d has no metadata", i)
+		}
+		var metadata llm.Metadata
+		if err := json.Unmarshal(message.Metadata, &metadata); err != nil {
+			t.Fatal(err)
+		}
+		if metadata.Provider == nil || *metadata.Provider != "test" ||
+			metadata.RequestedModel == nil || *metadata.RequestedModel != "test-model" {
+			t.Errorf("assistant %d metadata = %s", i, string(message.Metadata))
+		}
+		wantReason := "stop"
+		if i == 2 {
+			wantReason = "tool_calls"
+		}
+		if metadata.FinishReason == nil || *metadata.FinishReason != wantReason {
+			t.Errorf("assistant %d finish reason = %v", i, metadata.FinishReason)
+		}
+	}
 	for i, want := range wantRoles {
 		if stored[i].Sequence != i || stored[i].Role != want {
 			t.Errorf(
@@ -590,6 +616,7 @@ func TestCallTool(t *testing.T) {
 					Role:      llm.RoleAssistant,
 					ToolCalls: []llm.ToolCall{call},
 				},
+				&llm.Metadata{ID: new("assistant-completion")},
 				nil,
 			)
 			if err != nil {
@@ -644,7 +671,19 @@ func TestCallTool(t *testing.T) {
 			if err != nil {
 				t.Fatalf("json.Marshal: %v", err)
 			}
+			wantMetadata := `{"choice_index":null,"created":null,` +
+				`"finish_reason":null,"id":"assistant-completion",` +
+				`"logprobs":null,"model":null,"provider":null,` +
+				`"requested_model":null,"service_tier":null,` +
+				`"system_fingerprint":null,"timings":null,"usage":null}`
+			if assistant.Metadata == nil ||
+				string(assistant.Metadata) != wantMetadata {
+				t.Errorf("assistant metadata = %v", assistant.Metadata)
+			}
 			last := stored[len(stored)-1]
+			if last.Metadata != nil {
+				t.Errorf("tool metadata = %v, want nil", last.Metadata)
+			}
 			if last.Role != db.MessageRoleTool ||
 				last.Content != string(want) {
 				t.Errorf(