---
title: add_custom_attributes (Python agent API)
source: https://docs.newrelic.com/docs/apm/agents/python-agent/python-agent-api/addcustomattributes-python-agent-api
---

## Syntax

```py
newrelic.agent.add_custom_attributes(items)
```

Adds multiple custom attributes to a transaction.

## Description

This call records one or more [custom attributes](https://docs.newrelic.com/docs/new-relic-solutions/get-started/glossary/#attribute) (a key/value tuple attached to your [transaction](https://docs.newrelic.com/docs/new-relic-solutions/get-started/glossary/#transaction)).

Attributes may be found in APM if the transaction is associated with an error or if a transaction trace is generated for that transaction. Attributes can also be found and queried in the New Relic UI.

> #### ⚠️ IMPORTANT
>
> Before you create custom attributes, review our list of [reserved terms used by NRQL](https://docs.newrelic.com/docs/insights/event-data-sources/custom-events/data-requirements-limits-custom-event-data/#reserved-words).

## Attributes

| Attribute      | Description                                                                                                                                                                                                                                                                                                                                                                                                 |
| -------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `items` _list_ | Required. Each item in the list must be a `tuple`, with the first element being a _key_, and the second its _value_. Each key is a string representing the name of an attribute, and each corresponding value is the value to add to the current transaction for this attribute. Values can be `int`, `float`, `string`, or `boolean`. Only the first 255 characters are retained for both keys and values. |

## Return values

Returns `True` if all attributes were added successfully.

## Examples

### Adding custom attributes to background task [#custom-attribute-example]

An example of adding custom attributes to a [background task](https://docs.newrelic.com/docs/agents/python-agent/python-agent-api/background_task):

```py
@newrelic.agent.background_task()
def send_request():
    response = requests.get("http://example.com")
    newrelic.agent.add_custom_attributes(
        [("url_path_status_code", response.status_code)]
    )
```

### Using custom attributes to troubleshoot [#attribute-troubleshooting]

You can also use custom attributes to troubleshoot performance issues. For example, you might see occasional slow response times from a pool of memcache instances, but you don't know what instance is causing the problem. You might add an attribute to the transaction indicating the server, like so:

```py
# Set server_ip to be the current server processing the transaction
newrelic.agent.add_custom_attributes([
    ("memcache_query_frontend_lookup", server_ip)
])
```