SDK (Software Development Kit)
intermediateDefinition
A library that wraps an API to make it easier to use in a specific programming language. Instead of manually building HTTP requests, setting headers, and parsing JSON responses, you call functions like stripe.customers.create({name: 'Acme'}). SDKs handle authentication, retries, and error formatting for you. Most major SaaS tools publish official SDKs for Python, Node.js, and other popular languages.
In the wild
Instead of writing raw HTTP requests to the HubSpot API, you install the @hubspot/api-client SDK and call hubspotClient.crm.contacts.basicApi.getPage(): the SDK handles pagination, auth headers, and rate-limit retries automatically.
More from GTM & Business Tools
API Key
A secret string that identifies your application when it calls an external API: like a password for machines. Most SaaS tools (Stripe, SendGrid, HubSpot) issue API keys through their settings page. You include the key in your requests so the service knows who is calling and what permissions to grant. Never hard-code API keys in your source files; store them in environment variables.
CRM (Customer Relationship Management)
Software that tracks every interaction your company has with customers and prospects: emails sent, calls made, deals in progress, support tickets filed. Salesforce and HubSpot are the two most common. When you automate GTM workflows, the CRM is usually the system of record you read from and write back to.
Cron Job
A scheduled task that runs automatically at set intervals: every hour, every day at midnight, every Monday at 9 AM. The name comes from the Unix 'cron' utility, but the concept applies anywhere: GitHub Actions, cloud schedulers, and even no-code tools all support cron-style scheduling. GTM engineers use cron jobs to run recurring automations like nightly data syncs or weekly report generation.
CSV (Comma-Separated Values)
A plain-text file format where each line is a row of data and commas separate the columns. It is the universal exchange format for tabular data: almost every SaaS tool can export and import CSVs. They are simple but fragile: commas inside values need quoting, character encoding can vary, and large files can be slow to process row by row.
ETL (Extract, Transform, Load)
A three-step pattern for moving data between systems. Extract pulls data from a source (an API, a database, a CSV export). Transform reshapes it: renaming fields, filtering rows, converting formats. Load pushes the cleaned data into the destination system. Most GTM automations are some form of ETL, even if nobody calls it that.
JSON (JavaScript Object Notation)
The standard data format for APIs. JSON uses curly braces for objects, square brackets for arrays, and key-value pairs to structure data. Almost every modern API sends and receives JSON. Unlike CSVs, JSON can represent nested data, an object inside an object, which makes it flexible but slightly harder to read at first glance.