How to Pass Record ID to Third-Party Partner + Receive Images (Thumbnails)

[Jen_CPS]

Hi everyone, I'm integrating a third-party partner using a Private App and need guidance on two things:

1. Passing Record ID: When an existing contact submits a HubSpot form, we need the partner to receive that contact’s record ID. What’s the recommended way to pass or expose the record ID so the partner can reliably capture it?

2. Displaying Images as Thumbnails: Once the partner receives the Record ID he will send data and images to the contact record: Can they display as thumbnails instead of links? Is there a way to open them in a larger preview/lightbox? Looking for best practices or examples to achieve this.  Please see below how I would like it to look, once the image is sent back into Hubspot:

[RubenBurdin · Accepted solution]

Hi @Jen_CPS 

For the record ID part, the cleanest path is to grab it at the moment the form is submitted. A contact-based workflow can send the Record ID field straight to your partner through a webhook or your private app endpoint.

HubSpot’s forms don’t expose that ID natively, so sending it server-side avoids issues when the same person submits multiple times or uses different browsers. HubSpot shows how these record fields behave on submit in their property history docs here (https://knowledge.hubspot.com/properties/create-and-edit-properties )

For the images, HubSpot’s native UI won’t turn URLs or file uploads into a thumbnail gallery on its own. Even if your partner uploads the images through the Files tool or attaches them to engagements, they’ll appear as links or standard file previews. To get the layout in your screenshot, you’ll need a CRM UI extension placed in the right sidebar. HubSpot outlines how custom record cards work and how they receive the contact’s ID automatically here (https://developers.hubspot.com/docs/apps/developer-platform/add-features/ui-extensibility/app-cards/... )

That extension can call your partner’s API, retrieve the image URLs tied to the contact ID, and render them as thumbnails with a larger preview when clicked. If your partner also needs to keep those images and contact data aligned across systems, Stacksync keeps both sides mirrored as changes happen so you never end up with mismatched records. Hope this helps.

[Jaycee_Lewis]

Fantastic reply,@RubenBurdin 🙌 Thank you so much. — Jaycee

[BrandonWoodruff]

Hi there,

For your first question about passing the record ID:
The simplest and most reliable approach is to use a workflow or webhook that triggers when the form is submitted. That workflow can send the contact’s Record ID directly to your partner so they can store it on their end and reference it for any future updates.

Regarding the images, there are really two parts to consider:

1. Can the partner attach images to the contact?
   Yes. They can either upload images to HubSpot Files and associate them with the contact, or host the files externally and store the URLs on the record.

2. Can those images display as thumbnails or a gallery?
   HubSpot doesn’t automatically display file or URL properties as thumbnails.
   If the partner uploads files through the Files API or attaches them to engagements, HubSpot will show them as clickable links or standard attachments with a basic preview.
   If the partner stores URLs on the contact, those will also display as links only.

To achieve a true thumbnail gallery, you’ll need to use a CRM UI Extension. This allows you to place a custom “Images” card on the contact sidebar. The extension automatically receives the contact’s Record ID, can fetch image URLs from your partner’s system, and can display them as thumbnails with a larger preview or lightbox when clicked.

Let me know if this helps, or if you have any other questions!

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Brandon Woodruff Senior Software Developer @ Pearagon Still have questions? Reach out at brandon@pearagon.com

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