# Plugin > An index and topic collection covering plugin, extension, and add-on architectures with public APIs and marketplaces. This collection spans editor and IDE plugin ecosystems (VS Code Marketplace, JetBrains Marketplace, Chrome Web Store, Firefox Add-ons), SaaS platform extension marketplaces (Atlas... This is the **Plugin** topic area of [API Evangelist](https://apievangelist.com) — a network of focused knowledge bases drawn from 16 years of independent API research by Kin Lane. Browse all areas at https://apievangelist.com/areas/. ## Services & Tools - [VS Code Marketplace](https://providers.apis.io/providers/vs-code-marketplace/) (repo: https://github.com/api-evangelist/vs-code-marketplace) - [JetBrains Marketplace](https://providers.apis.io/providers/jetbrains-plugin/) (repo: https://github.com/api-evangelist/jetbrains-plugin) - [Google Chrome](https://providers.apis.io/providers/google-chrome/) (repo: https://github.com/api-evangelist/google-chrome) - [Atlassian](https://providers.apis.io/providers/atlassian/) (repo: https://github.com/api-evangelist/atlassian) - [Salesforce](https://providers.apis.io/providers/salesforce/) (repo: https://github.com/api-evangelist/salesforce) - [Shopify](https://providers.apis.io/providers/shopify/) (repo: https://github.com/api-evangelist/shopify) - [WordPress](https://providers.apis.io/providers/wordpress/) (repo: https://github.com/api-evangelist/wordpress) - [Slack](https://providers.apis.io/providers/slack/) (repo: https://github.com/api-evangelist/slack) - [Discord](https://providers.apis.io/providers/discord/) (repo: https://github.com/api-evangelist/discord) - [Microsoft Office 365](https://providers.apis.io/providers/microsoft-office-365/) (repo: https://github.com/api-evangelist/microsoft-office-365) - [Google Workspace](https://providers.apis.io/providers/google-workspace/) (repo: https://github.com/api-evangelist/google-workspace) - [Notion](https://providers.apis.io/providers/notion/) (repo: https://github.com/api-evangelist/notion) - [Postman](https://providers.apis.io/providers/postman/) (repo: https://github.com/api-evangelist/postman) - [Figma](https://providers.apis.io/providers/figma/) (repo: https://github.com/api-evangelist/figma) - [Webflow](https://providers.apis.io/providers/webflow/) (repo: https://github.com/api-evangelist/webflow) - [HubSpot](https://providers.apis.io/providers/hubspot/) (repo: https://github.com/api-evangelist/hubspot) - [Zapier](https://providers.apis.io/providers/zapier/) (repo: https://github.com/api-evangelist/zapier) - [Auth0](https://providers.apis.io/providers/auth0/) (repo: https://github.com/api-evangelist/auth0) - [Kong](https://providers.apis.io/providers/kong/) (repo: https://github.com/api-evangelist/kong) - [Tyk](https://providers.apis.io/providers/tyk/) (repo: https://github.com/api-evangelist/tyk) - [Gravitee](https://providers.apis.io/providers/gravitee/) (repo: https://github.com/api-evangelist/gravitee) - [Open WebUI](https://providers.apis.io/providers/open-webui/) (repo: https://github.com/api-evangelist/open-webui) - [ChatGPT](https://providers.apis.io/providers/chatgpt/) (repo: https://github.com/api-evangelist/chatgpt) - [OpenAI](https://providers.apis.io/providers/openai/) (repo: https://github.com/api-evangelist/openai) - [Claude](https://providers.apis.io/providers/claude/) (repo: https://github.com/api-evangelist/claude) ## Common Features - **Plugin Manifests**: Marketplaces and runtimes use declarative manifests (manifest.json for Chrome and VS Code, plugin.xml for JetBrains, app manifests for Slack and Atlassian Connect) to describe identity, permissions, entry points, and capabilities of a plugin. - **Marketplace Listing and Discovery APIs**: Public APIs and search endpoints expose listings, categories, ratings, and download counts so developers and users can discover plugins across VS Code Marketplace, Chrome Web Store, JetBrains Marketplace, Shopify App Store, and Atlassian Marketplace. - **Extension Points and Hooks**: Host platforms expose well-defined extension points, events, and lifecycle hooks (Forge modules, Shopify Functions, Auth0 Actions, Kong plugin phases, WordPress hooks) that plugins implement to integrate with the host. - **Install, Update, and Entitlement Flows**: Marketplaces standardize installation, OAuth grant, license check, and entitlement validation flows for individual users, organizations, and tenants, including paid plugin billing and trials. - **Sandboxing and Permissions**: Plugin runtimes enforce permission scopes, sandboxed execution (Atlassian Forge, Chrome MV3 service workers, Slack Bolt scopes, Salesforce managed packages) and review processes to protect host platforms and end users. - **AI Tooling and Agent Plugins**: AI platforms expose plugin and tool surfaces (ChatGPT GPTs and plugins, Open WebUI Functions, Claude Code plugins, OpenAI tools) that let third-party developers extend LLM behavior with custom actions, retrieval, and integrations. - **API Gateway Plugin Frameworks**: API gateways such as Kong, Tyk, and Gravitee define plugin frameworks where authentication, transformation, rate limiting, and observability behavior is implemented and distributed as installable plugins. ## Use Cases - **Editor and IDE Extensibility**: Developers ship language support, linters, debuggers, and AI assistants as plugins through VS Code Marketplace and JetBrains Marketplace, reaching millions of editor installations through manifest-driven distribution. - **SaaS Platform App Marketplaces**: ISVs build and list apps on Salesforce AppExchange, Shopify App Store, Atlassian Marketplace, HubSpot Marketplace, and Slack App Directory to extend SaaS platforms and reach enterprise customers. - **Browser Extension Distribution**: Developers package and distribute browser extensions for content blocking, productivity, password management, and accessibility through Chrome Web Store, Firefox Add-ons, and Microsoft Edge Add-ons. - **API Gateway Customization**: Platform teams extend Kong, Tyk, and Gravitee with custom plugins for authentication, request transformation, AI prompt firewalls, and policy enforcement, often shared through plugin hubs. - **CMS and Commerce Extensibility**: WordPress plugin directory and Shopify App Store let merchants and publishers extend CMS and commerce platforms with payment processors, shipping integrations, page builders, and analytics. - **AI Agent Tooling**: Builders publish ChatGPT GPTs and plugins, Open WebUI Functions, and Claude Code plugins to give AI agents domain-specific tools, retrieval sources, and connectors to external systems. - **Identity and Access Extensions**: Auth0 Actions, Extensions, and the Auth0 Marketplace let teams add custom rules, MFA providers, and SSO integrations to identity flows without forking the platform. ## Related Areas - [Aggregation](https://aggregation.apievangelist.com): An index and topic collection covering API aggregation, marketplaces, directories, unified APIs, and catalog platform... - [Portal](https://portal.apievangelist.com): A curated index of services, tooling, and open source solutions for API developer portals, API catalogs, API marketpl... ## More - [Latest Plugin stories](/stories/) - [All API Evangelist topic areas](https://apievangelist.com/areas/) - [API Evangelist network index (llms.txt)](https://apievangelist.com/llms.txt)