---
title: "Update the contents of a collection"
method: PUT
path: "/v1/collections/{collection_id}/content"
tags: ["Collections"]
---

# Update the contents of a collection

`PUT /v1/collections/{collection_id}/content`

Replace the contents of a collection (the `data` from when you created or updated a collection). The request is a free-form object containing the keys you want to reference from the collection and the corresponding values. This request replaces the current contents of the collection entirely.

If you don't want to update the contents directly—you want to change the `name` or data `url` for your collection, use the [update a collection](/integrations/api/app/tag/collections/updateCollection/) endpoint.

**Note**: A collection cannot be more than 10 MB in size. No individual row in the collection can be more than 10 KB.

## Request body

- object

## Response `200`

Returns your collection metadata and the updated schema.

- object
  - `collection` CollectionResponse
    - `bytes` integer — The size of the collection in bytes.
    - `created_at` integer — The date time when the referenced ID was created.
    - `updated_at` integer — The date time when the referenced ID was last updated.
    - `id` integer — The identifier for the collection. This is how you'll reference the collection from the API.
    - `name` string — The name of the collection. This is how you'll reference the collection in liquid, e.g. `{{collection_name.data_property}}`.
    - `rows` integer — Represents the number of objects in the `data` array or CSV rows in your collection schema.
    - `schema` string[] — Lists the top-level keys that you can reference within this collection. Customer.io does not enforce any of these keys as required from your `data`.

## Other responses

- `404` — The collection `id` does not exist.
- `429` — Your request is over the 10-per-second limit. `Retry-After` tells you how many seconds you must wait before you send the next request.

## Changes

- **2026-09-02** `5da2740beeb5` — 1 info
  - added the media type `application/json` for the response with the status `429`

[Change history](https://skmtc.dev/customer/apis/customer-io-journeys-api-reference/changes/v1/collections/:collection_id/content/put.md)

---

[API](https://skmtc.dev/customer/apis/customer-io-journeys-api-reference.md) · [All operations](https://skmtc.dev/customer/apis/customer-io-journeys-api-reference/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/customer/customer-io-journeys-api-reference/revisions/5da2740beeb5/schema)