docs/apps/tasks-docs/content/docs/concepts/retry-policies.mdx

---
title: Retry Policies
description: Configure automatic retry behavior for failed activities
---

import { Tab, Tabs } from '@hanzo/docs-base-ui/components/tabs';

# Retry Policies

Retry policies define how Hanzo Tasks automatically retries failed activities. Every activity has a default retry policy, and you can customize it per activity.

## Default Behavior

By default, activities retry **infinitely** with exponential backoff:

- Initial interval: 1 second
- Backoff coefficient: 2.0
- Maximum interval: 100 seconds
- Maximum attempts: unlimited

## Customizing Retry Policies

<Tabs items={['Go', 'Python']}>
<Tab value="Go">
```go
retryPolicy := &temporal.RetryPolicy{
    // First retry after 1 second
    InitialInterval: time.Second,

    // Double the interval each retry
    BackoffCoefficient: 2.0,

    // Cap the interval at 1 minute
    MaximumInterval: time.Minute,

    // Give up after 5 attempts
    MaximumAttempts: 5,

    // Don't retry these error types
    NonRetryableErrorTypes: []string{
        "InvalidInputError",
        "AuthenticationError",
    },
}

opts := workflow.ActivityOptions{
    StartToCloseTimeout: 5 * time.Minute,
    RetryPolicy:         retryPolicy,
}
```
</Tab>

<Tab value="Python">
```python
from hanzo_tasks import RetryPolicy
from datetime import timedelta

retry_policy = RetryPolicy(
    # First retry after 1 second
    initial_interval=timedelta(seconds=1),

    # Double the interval each retry
    backoff_coefficient=2.0,

    # Cap the interval at 1 minute
    maximum_interval=timedelta(minutes=1),

    # Give up after 5 attempts
    maximum_attempts=5,

    # Don't retry these error types
    non_retryable_error_types=["InvalidInputError", "AuthenticationError"],
)

result = await workflow.execute_activity(
    my_activity, input,
    start_to_close_timeout=timedelta(minutes=5),
    retry_policy=retry_policy,
)
```
</Tab>
</Tabs>

## Retry Timeline Example

With `InitialInterval=1s`, `BackoffCoefficient=2.0`, `MaximumInterval=60s`, `MaximumAttempts=5`:

| Attempt | Delay Before | Cumulative Time |
|---------|-------------|-----------------|
| 1 | 0s (immediate) | 0s |
| 2 | 1s | 1s |
| 3 | 2s | 3s |
| 4 | 4s | 7s |
| 5 | 8s | 15s |
| (fail) | -- | Activity marked as failed |

## Non-Retryable Errors

Some errors should not be retried (invalid input, authentication failures, business logic errors). Mark them as non-retryable:

```go
// In your activity, return an application error with non-retryable flag
return temporal.NewNonRetryableApplicationError("invalid input", "InvalidInputError", nil)
```

```python
# In your activity, raise a non-retryable error
raise ApplicationError("invalid input", type="InvalidInputError", non_retryable=True)
```