# Plugin

**Canonical:** https://apis.io/providers/plugin/  
**Website:** https://apievangelist.com  
**APIs profiled:** 0

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 (Atlassian Marketplace and Forge, Salesforce AppExchange, Shopify App Store, WordPress Plugins, Slack Apps, Discord Apps, Microsoft AppSource, Google Workspace Marketplace, Notion, Postman, Figma, Sketch, Webflow Apps, HubSpot Marketplace, Zapier App Directory), API gateway plugin frameworks (Kong Plugin Hub, Tyk Plugins, Gravitee Plugins), identity extensibility (Auth0 Actions and Extensions), and AI plugin and tool ecosystems (Open WebUI Functions, ChatGPT Plugins and GPTs, Claude Code plugins, OpenAI tools). It tracks the manifests, listing schemas, install and entitlement flows, extension points, and review and distribution APIs that power modern plugin and extension marketplaces.

## Kin Score — 9.6 / 100 (minimal)

Scored 2026-10-23 under rubric 0.25.0. Trend: flat (+0.0 from 9.6).

| Facet | Score |
|---|---|
| Discoverability | 48.2 |
| Contract Quality | 14.7 |
| Contract Governance | 0.0 |
| Operational Transparency | 5.3 |
| Developer Ergonomics | 9.5 |
| Access Clarity | 0.0 |

Regulatory layer — **Horizontal (data, software, accessibility, platform)**: 4.9 (matched via fallback).

## Agent readiness — 0.0 (human-only)

| Dimension | Value |
|---|---|
| Spec Presence | no |
| Agentic Access | no |
| Reversibility Documented | no |
| MCP Server | no |
| Auth Clarity | no |
| Idempotency | no |
| Error Semantics | no |
| OpenAPI Examples | no |
| Rate Limit Signal | no |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |
| Delegated Identity | no |
| Protected Resource Metadata | no |
| Dynamic Client Registration | no |
| Agentic Commerce | no |
| Pagination Ratio | na |
| Operation Distinctiveness | na |

## Use cases (7)

- **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 installatio...
- **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 ent...
- **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 Mi...
- **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 p...
- **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, an...
- **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 s...
- **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.

## Tags

Plugins, Extension, Marketplace, App Directory, Addon

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/plugin/). Scores are computed from the provider's own public artifacts under a published rubric.