vxcontrol/pentagi · error

failed to create flow agent log: %w

Error message

failed to create flow agent log: %w

What it means

newFlowProviderWorkers builds the per-flow log worker set when a flow starts. Its first step creates the agent log worker via cnts.alc.NewFlowAgentLog(ctx, flowID, pub); any error is wrapped with this message and aborts flow worker construction, so the flow fails to start rather than run without agent event logging.

Source

Thrown at backend/pkg/controller/flow.go:1169

	} else {
		span.End(
			langfuse.WithSpanOutput(result),
			langfuse.WithSpanStatus("success"),
		)
	}

	return nil
}

func newFlowProviderWorkers(
	ctx context.Context,
	flowID int64,
	cnts *flowProviderControllers,
	pub subscriptions.FlowPublisher,
) (*flowProviderWorkers, error) {
	alw, err := cnts.alc.NewFlowAgentLog(ctx, flowID, pub)
	if err != nil {
		return nil, fmt.Errorf("failed to create flow agent log: %w", err)
	}

	mlw, err := cnts.mlc.NewFlowMsgLog(ctx, flowID, pub)
	if err != nil {
		return nil, fmt.Errorf("failed to create flow msg log: %w", err)
	}

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

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

	vslw, err := cnts.vslc.NewFlowVectorStoreLog(ctx, flowID, pub)

View on GitHub (pinned to ea665308ba)

Solutions

1. Check the wrapped error and Postgres logs for the underlying failure
2. Run pending goose migrations so the agent-log schema is current
3. Verify DB connectivity/pool settings, then retry flow creation
4. Confirm the flow ID exists in the flows table before creating workers

Example fix

// before: create workers with no DB health check
workers, err := newFlowProviderWorkers(ctx, flowID, cnts, pub)
// after: precondition the DB and pass a fresh context with deadline
if err := db.PingContext(ctx); err != nil {
    return nil, fmt.Errorf("db unavailable before flow start: %w", err)
}
ctx, cancel := context.WithTimeout(ctx, 30*time.Second)
defer cancel()
workers, err := newFlowProviderWorkers(ctx, flowID, cnts, pub)

if err := db.PingContext(ctx); err != nil {
    return fmt.Errorf("db unavailable, cannot start flow: %w", err)
}

func hasValidFlowID(flowID int64) bool { return flowID > 0 }

alw, err := cnts.alc.NewFlowAgentLog(ctx, flowID, pub)
if err != nil {
    if isTransientDBError(err) { /* retry up to 3x with backoff */ }
    return nil, fmt.Errorf("failed to create flow agent log (flow=%d): %w", flowID, err)
}

When it happens

Trigger: Creating a new flow (or restoring its workers) calls newFlowProviderWorkers and NewFlowAgentLog fails — usually a database error inserting/initializing the agent log, or the flow ID is invalid/nonexistent.

Common situations: PostgreSQL down or connection pool exhausted at flow creation time; flow row not yet committed when workers are created; concurrent flow deletion; DB schema out of date (missing migration).

Related errors

• failed to create flow msg log: %w
• failed to create flow search log: %w
• failed to create flow term log: %w
• failed to create flow vector store log: %w
• failed to create flow tool call log: %w

AI-assisted analysis of vxcontrol/pentagi@ea665308ba (2026-09-01). Data as JSON: /api/errors/7638ae336e7f96f8. Report an issue: GitHub.