Serverless functions for the CMS

Supported products

Requires one of the following products or higher.

Content HubEnterprise

• Collect and store data in HubDB or the HubSpot CRM
• Run complex data calculators
• Dynamically fetch and display data from external systems
• Send form data to external systems

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Limits

• 50 secrets per account.
• 128MB of memory.
• no more than 100 endpoints per HubSpot account.
• the contentType application/json when calling a function.
• 6MB per invocation payload, which you might encounter when trying to upload a file with a serverless function, for example.
• 4KB for the amount of data that can be logged. When hitting this limit, it’s recommended to log after individual actions, rather than the final output.

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Execution limits

• Each function has a maximum of 10 seconds of execution time.
• Each account is limited to 600 total execution seconds per minute.

• Up to 60 function executions that take 10 seconds each to complete.
• Up to 6,000 function executions that take 100 milliseconds to complete.

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Split dependencies

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Building functions

• serverless.json: the serverless function’s configuration file, which includes definitions for the function name, JavaScript file path, included secrets, and endpoint details.
• .js file: the code that gets executed when the function is invoked. This file can have any name, as long as it ends in .js. You’ll specify the file name in the serverless.json file.
• package.json (project-based only): for serverless functions built with projects, this file configures dependencies needed to execute the function.

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Developer projects

project-folder/
│── src/
├──── app
│     ├── app.json
│     ├── app.functions/
│       ├── function.js
│       ├── package.json
│       └── serverless.json
└─ hsproject.json

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Design manager

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Authentication

• Private app access tokens: because project-based serverless functions are bundled inside a private app, you can reference the app’s access token directly in your JavaScript code. Requests will have access to the scopes assigned to the private app. For serverless functions built in the design manager, you’ll need to create a secret to store a private app access token value. Calls authenticated with a private app access token count against your API call limits.
• Secrets: create secrets using the CLI to store credentials securely in HubSpot. You can make a secret available to a serverless function by including the secret name in the serverless.json file. Learn more about managing secrets using the HubSpot CLI.

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Debugging

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Project-based serverless functions

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In-app debugging

• In your HubSpot account, navigate to CRM Development.
• In the left sidebar menu, navigate to Private apps.
• Select the private app that contains the serverless function.
• Click the Logs tab.
• To view logs for a serverless app function, click the Serverless functions tab. To view logs for a serverless endpoint function, click the Endpoint functions tab.
• In each tab, you can view logs for specific requests by clicking the request. You can also use the search bar to search by request ID.
• In the right panel, you can then click View log trace for a more in-depth breakdown of the request.

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Local debugging

• Log messages that record the execution of a function, along with its status and timing. For example: 2021-04-28T19:19:21.666Z - SUCCESS - Execution Time: 279ms
• Log messages that are produced through console statements in the function code. For example, your serverless function JavaScript might include:

exports.main = async (context) => {
  console.log('Log some debug info');
  console.error('An error occurred');
  return {
    statusCode: 200,
    body: { message: 'Hello World' },
  };
};

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Design manager serverless functions