---
title: "Default Exporter | Tracing | Observability"
description: "Store traces locally for development and debugging"
packages:
  - "@mastra/core"
  - "@mastra/libsql"
  - "@mastra/observability"
---

# Default Exporter

The `DefaultExporter` persists traces to your configured storage backend, making them accessible through Studio. It's automatically enabled when using the default observability configuration and requires no external services.

## Configuration

### Prerequisites

1. **Storage Backend**: Configure a storage provider (libSQL, PostgreSQL, etc.)
2. **Studio**: Install for viewing traces locally

### Basic Setup

```typescript title="src/mastra/index.ts"
import { Mastra } from "@mastra/core";
import { Observability, DefaultExporter } from "@mastra/observability";
import { LibSQLStore } from "@mastra/libsql";

export const mastra = new Mastra({
  storage: new LibSQLStore({
    id: 'mastra-storage',
    url: "file:./mastra.db", // Required for trace persistence
  }),
  observability: new Observability({
    configs: {
      local: {
        serviceName: "my-service",
        exporters: [new DefaultExporter()],
      },
    },
  }),
});
```

### Recommended Configuration

Include DefaultExporter in your observability configuration:

```typescript
import { Mastra } from "@mastra/core";
import {
  Observability,
  DefaultExporter,
  CloudExporter,
  SensitiveDataFilter,
} from "@mastra/observability";
import { LibSQLStore } from "@mastra/libsql";

export const mastra = new Mastra({
  storage: new LibSQLStore({
    id: 'mastra-storage',
    url: "file:./mastra.db",
  }),
  observability: new Observability({
    configs: {
      default: {
        serviceName: "mastra",
        exporters: [
          new DefaultExporter(), // Persists traces to storage for Mastra Studio
          new CloudExporter(), // Sends traces to Mastra Cloud (requires MASTRA_CLOUD_ACCESS_TOKEN)
        ],
        spanOutputProcessors: [
          new SensitiveDataFilter(),
        ],
      },
    },
  }),
});
```

## Viewing Traces

### Studio

Access your traces through Studio:

1. Start Studio
2. Navigate to Observability
3. Filter and search your local traces
4. Inspect detailed span information

## Tracing Strategies

DefaultExporter automatically selects the optimal tracing strategy based on your storage provider. You can also override this selection if needed.

### Available Strategies

| Strategy               | Description                                               | Use Case                            |
| ---------------------- | --------------------------------------------------------- | ----------------------------------- |
| **realtime**           | Process each event immediately                            | Development, debugging, low traffic |
| **batch-with-updates** | Buffer events and batch write with full lifecycle support | Low volume Production               |
| **insert-only**        | Only process completed spans, ignore updates              | High volume Production              |

### Strategy Configuration

```typescript
new DefaultExporter({
  strategy: "auto", // Default - let storage provider decide
  // or explicitly set:
  // strategy: 'realtime' | 'batch-with-updates' | 'insert-only'

  // Batching configuration (applies to both batch-with-updates and insert-only)
  maxBatchSize: 1000, // Max spans per batch
  maxBatchWaitMs: 5000, // Max wait before flushing
  maxBufferSize: 10000, // Max spans to buffer
});
```

## Storage Provider Support

Different storage providers support different tracing strategies.

If you set the strategy to `'auto'`, the `DefaultExporter` automatically selects the optimal strategy for the storage provider. If you set the strategy to a mode that the storage provider doesn't support, you will get an error message.

| Storage Provider                                | Preferred Strategy | Supported Strategies                      | Notes                                 |
| ----------------------------------------------- | ------------------ | ----------------------------------------- | ------------------------------------- |
| **[libSQL](/reference/v1/storage/libsql)**         | batch-with-updates | realtime, batch-with-updates, insert-only | Default storage, good for development |
| **[PostgreSQL](/reference/v1/storage/postgresql)** | batch-with-updates | batch-with-updates, insert-only           | Recommended for production            |

### Strategy Benefits

- **realtime**: Immediate visibility, best for debugging
- **batch-with-updates**: 10-100x throughput improvement, full span lifecycle
- **insert-only**: Additional 70% reduction in database operations, perfect for analytics

## Batching Behavior

### Flush Triggers

For both batch strategies (`batch-with-updates` and `insert-only`), traces are flushed to storage when any of these conditions are met:

1. **Size trigger**: Buffer reaches `maxBatchSize` spans
2. **Time trigger**: `maxBatchWaitMs` elapsed since first event
3. **Emergency flush**: Buffer approaches `maxBufferSize` limit
4. **Shutdown**: Force flush all pending events

### Error Handling

The DefaultExporter includes robust error handling for production use:

- **Retry Logic**: Exponential backoff (500ms, 1s, 2s, 4s)
- **Transient Failures**: Automatic retry with backoff
- **Persistent Failures**: Drop batch after 4 failed attempts
- **Buffer Overflow**: Prevent memory issues during storage outages

### Configuration Examples

```typescript
// Zero config - recommended for most users
new DefaultExporter();

// Development override
new DefaultExporter({
  strategy: "realtime", // Immediate visibility for debugging
});

// High-throughput production
new DefaultExporter({
  maxBatchSize: 2000, // Larger batches
  maxBatchWaitMs: 10000, // Wait longer to fill batches
  maxBufferSize: 50000, // Handle longer outages
});

// Low-latency production
new DefaultExporter({
  maxBatchSize: 100, // Smaller batches
  maxBatchWaitMs: 1000, // Flush quickly
});
```

## Related

- [Tracing Overview](/docs/v1/observability/tracing/overview)
- [CloudExporter](/docs/v1/observability/tracing/exporters/cloud)
- [Storage Configuration](/docs/v1/memory/storage)
