What causes "failed to get flow tool call log: %w" in vxcontrol/pentagi?

Inspect the wrapped error for the underlying DB cause.

failed to get flow tool call log: %w

Error message

failed to get flow tool call log: %w

What it means

Wraps a failure from cnts.tclc.GetFlowToolCallLog(ctx, flowID); the tool-call log stream for the flow could not be retrieved during flowProviderWorkers assembly. Root cause preserved via %w. This is the last log fetcher before the screenshot fetch in the sequence.

Source

Thrown at backend/pkg/controller/flow.go:1245

	slw, err := cnts.slc.GetFlowSearchLog(ctx, flowID)
	if err != nil {
		return nil, fmt.Errorf("failed to get flow search log: %w", err)
	}

	tlw, err := cnts.tlc.GetFlowTermLog(ctx, flowID)
	if err != nil {
		return nil, fmt.Errorf("failed to get flow term log: %w", err)
	}

	vslw, err := cnts.vslc.GetFlowVectorStoreLog(ctx, flowID)
	if err != nil {
		return nil, fmt.Errorf("failed to get flow vector store log: %w", err)
	}

	tclw, err := cnts.tclc.GetFlowToolCallLog(ctx, flowID)
	if err != nil {
		return nil, fmt.Errorf("failed to get flow tool call log: %w", err)
	}

	sw, err := cnts.sc.GetFlowScreenshot(ctx, flowID)
	if err != nil {
		return nil, fmt.Errorf("failed to get flow screenshot: %w", err)
	}

	return &flowProviderWorkers{
		mlw:  mlw,
		alw:  alw,
		slw:  slw,
		tlw:  tlw,
		vslw: vslw,
		tclw: tclw,
		sw:   sw,
	}, nil
}

View on GitHub (pinned to ea665308ba)

Solutions

Inspect the wrapped error for the underlying DB cause.
Verify the flowID exists in the current DB.
Apply pending migrations so tool-call-log tables exist.
Retry transient errors; check DB health/pool metrics.

Defensive patterns

Strategy: try-catch

Validate before calling

var exists bool
err := db.QueryRow("SELECT EXISTS(SELECT 1 FROM flows WHERE id=$1)", flowID).Scan(&exists)
if err != nil || !exists { /* abort with 404 */ }

Type guard

func isToolCallLogError(err error) bool {
	return err != nil && strings.Contains(err.Error(), "failed to get flow tool call log")
}

Try / catch

tclw, err := cnts.tclc.GetFlowToolCallLog(ctx, flowID)
if err != nil {
	if isTransient(err) { /* retry with backoff */ }
	return nil, fmt.Errorf("failed to get flow tool call log: %w", err)
}

Prevention

Validate flowID before fetching logs.
Keep tool-call-log migrations in sync with releases.
Monitor DB health and pool metrics.
Use errors.Is/As to classify wrapped causes.

When it happens

Trigger: Flow log retrieval where the tool-call-log storage query for flowID returns an error (missing flow, DB failure).

Common situations: Tool-call tables absent due to skipped migrations; DB connection issues; querying a flow from a stale/different database.

Related errors

AI-assisted analysis of vxcontrol/pentagi@ea665308ba (2026-09-01). Data as JSON: /api/errors/4ab4c585a24539d9. Report an issue: GitHub.