Catalog›Agent skills›Security & identity›function-creatorFCfunction-creatorCreate Convex queries, mutations, and actions with proper validation, authentication, and error handling. Use when implementing new API endp Open site Project Open in the app JSON README (API)Create Convex queries, mutations, and actions with proper validation, authentication, and error handling. Use when implementing new API endpoints.READMELoading documentation…# Convex Agent Plugins Official Convex plugins for AI coding agents, providing comprehensive development tools for building reactive backends with TypeScript. **Supported Agents:** Cursor, Claude Code (more coming soon) ## Overview This plugin makes Convex development easier by providing: - **18 Best Practice Rules** — Persistent AI guidance for query optimization, security, schema design, and more - **6 Specialized Skills** — Expert agent capabilities including quickstart, schema building, function creation, authentication, and migrations - **2 Custom Agents** — Specialized advisor and code reviewer for Convex development - **MCP Integration** — Direct access to your Convex deployment data and operations - **Development Hooks** — pre-commit checks (blocking) and an end-of-turn verify retry-loop (non-blocking; see [Cursor plugin mechanism status](#cursor-plugin-mechanism-status)) ## What is Convex? [Convex](https://convex.dev) is the reactive backend-as-a-service where you build your entire backend in TypeScript. It provides: - **Reactive Database** — Real-time queries that automatically update your UI - **Serverless Functions** — Write queries, mutations, and actions in TypeScript - **Built-in Auth** — Integrate with WorkOS, Auth0, or custom JWT providers - **Type Safety** — End-to-end TypeScript with automatic type generation - **Vector Search** — Built-in vector database for AI applications ## Installation Install this plugin via the Cursor Marketplace or manually: ```bash # Clone or download this plugin cd ~/.cursor/plugins git clone <this-repo-url> convex # Restart Cursor ``` ## Components ### Intelligent Assistance The plugin helps the AI understand when Convex might be a good fit for your project, such as when you're building real-time features, setting up a backend, or starting a new application. It provides relevant guidance and can help with setup when needed. ### Rules (Always Active) The plugin includes 18 rules that provide persistent AI guidance: **Development Best Practices:** 1. **async-handling** — Always await promises to prevent unexpected behavior 2. **query-optimization** — Use indexes instead of `.filter()` for efficient queries 3. **argument-validation** — All public functions must validate args and returns 4. **authentication-checks** — Implement auth checks in all protected functions 5. **schema-design** — Design flat, relational schemas with proper indexes 6. **function-organization** — Keep wrappers thin, put logic in TypeScript functions 7. **scheduler-usage** — Only schedule internal functions, never api functions 8. **no-date-now-in-queries** — Avoid Date.now() in queries (breaks reactivity) 9. **use-node-for-actions** — Use "use node" directive when actions need Node.js APIs 10. **custom-functions-for-auth** — Data protection patterns (Convex's RLS alternative) 11. **use-components-for-encapsulation** — Sibling components for modularity 12. **use-eslint-always** — ESLint with @convex-dev/eslint-plugin is mandatory 13. **typescript-strict-no-any** — TypeScript strict mode, avoid 'any' type 14. **error-handling-patterns** — Proper error handling (throw vs return null) 15. **local-development-agent-mode** — Agent mode for cloud coding agents 16. **use-pagination-for-large-datasets** — Cursor-based pagination for performance Plus contextual rules for new projects, real-time features, and deployment workflows. Rules automatically guide the AI when working in your `convex/` directory. ### Skills (On-Demand Expertise) Invoke specialized agent capabilities for complex Convex tasks: #### `/convex-quickstart` Initialize a new Convex backend from scratch with schema, auth, and CRUD operations. **Use when:** - Starting a brand new project with Convex - Adding Convex to an existing React/Next.js app - Need step-by-step setup guidance **Example:** ``` User: "Set up a Convex backend for my project" Assistant: [Walks through installation, schema, auth, and CRUD setup] ``` #### `/schema-builder` Design and generate database schemas with proper validation, indexes, and relationships. **Use when:** - Creating `convex/schema.ts` - Adding tables or modifying structure - Converting nested data to relational design - Optimizing indexes **Example:** ``` User: "Create a schema for a task management app with users, teams, and tasks" Assistant: [Generates complete schema with proper indexes and relationships] ``` #### `/function-creator` Create queries, mutations, and actions with proper validation, auth, and error handling. **Use when:** - Implementing new API endpoints - Creating CRUD operations - Adding authenticated functions - Writing actions that call external APIs **Example:** ``` User: "Create a mutation to update a task with ownership check" Assistant: [Generates secure mutation with auth and authorization] ``` #### `/auth-setup` Set up authentication with user management, identity mapping, and access control. **Use when:** - Implementing authentication for the first time - Setting up OAuth providers (WorkOS, Auth0) - Creating auth helper functions - Implementing role-based access control **Example:** ``` User: "Set up WorkOS authentication with user roles" Assistant: [Creates users table, auth helpers, and role checking functions] ``` #### `/migration-helper` Plan and execute schema migrations safely without downtime. **Use when:** - Adding required fields to existing tables - Changing field types or structure - Migrating from arrays to relational tables - Renaming fields **Example:** ``` User: "Migrate tags array to a separate tags table" Assistant: [Creates migration plan with dual-write pattern and batch processing] ``` ### Custom Agents The plugin includes specialized agents for Convex development: #### `convex-advisor` Provides guidance on Convex architecture and development patterns. - Helps with backend architecture decisions - Explains Convex features and capabilities - Provides migration paths from other databases - Answers questions about Convex best practices #### `convex-reviewer` Code reviewer specialized in Convex best practices. - Security: Auth, validation, authorization - Performance: Indexes, query optimization - Code quality: Organization, type safety - Identifies Convex-specific anti-patterns ### MCP Server Integration The plugin includes MCP (Model Context Protocol) integration for direct access to your Convex deployment: - Query your database schema - Read deployment configuration - Access environment variables - View function definitions - Check deployment status **Configuration:** Set these environment variables: ```bash export CONVEX_DEPLOYMENT="your-deployment-name" export CONVEX_DEPLOY_KEY="your-deploy-key" ``` ### Development Hooks The plugin ships two Cursor hooks (`hooks.json`, wired via `.cursor-plugin/plugin.json`'s `hooks` field — see [Cursor's hooks docs](https://cursor.com/docs/hooks) for the full event list and schema). These are real Cursor mechanisms, not just instructions: each is a spawned script that Cursor calls automatically and whose JSON output Cursor acts on. #### Pre-Commit Checks (`beforeShellExecution`) Runs before any shell command matching `git commit`; can **deny** the commit outright. - **Checks:** `Date.now()` inside/near `query({...})` bodies, `.filter()` chained on `db.query(...)`. - **Script:** `scripts/pre-commit-checks.sh` #### End-of-Turn Verify (`stop`) Fires when the agent's turn ends (`status: "completed"`). Cursor's `stop` hook **cannot block** completion — but it can return a `followup_message` that Cursor automatically submits as the next user turn, capped by `loop_limit` (set to `2` here) so it can't loop forever. This turns the SELF-VERIFY RULE already in `rules/quickstart.mdc` (run `npx tsc --noEmit` before declaring backend work done) from an instruction the agent might forget into a mechanism that catches it if it does: if `convex/` exists and `npx tsc --noEmit` fails, the hook auto-submits a follow-up turn with the compiler errors so the agent fixes them before the session is really "done". - **Script:** `scripts/stop-verify.sh` - **Honest limitation:** this is a retry-loop, not a hard gate — Cursor has no hook that blocks turn completion the way Claude Code's `Stop` hook or a CI gate would. A user who ignores the follow-up (or an agent that exhausts the loop limit) can still end the session with a broken build. See [Cursor plugin mechanism status](#cursor-plugin-mechanism-status) below for how this compares to the Claude Code and Codex equivalents. ## Usage Examples ### Creating a New Schema ```typescript // Simply ask the AI: "Create a schema for a blog with users, posts, and comments"; // The plugin's schema-builder skill will guide the creation of: // - Properly indexed tables // - Relational structure (no deep nesting) // - Correct validator types // - Compound indexes for common queries ``` ### Implementing Authentication ```typescript // Ask: "Set up authentication with WorkOS and create a getCurrentUser helper"; // The auth-setup skill will create: // - users table with tokenIdentifier index // - getCurrentUser helper function // - storeUser mutation for first sign-in // - Example access control patterns ``` ### Building Secure CRUD Operations ```typescript // Ask: "Create CRUD operations for tasks with ownership checks"; // The function-creator skill will generate: // - Properly validated functions // - Authentication checks // - Authorization (ownership) checks // - Indexed queries (no .filter()) // - Error handling ``` ### Migrating Schema Safely ```typescript // Ask: "I need to add a required 'status' field to existing tasks"; // The migration-helper skill will: // 1. Add field as optional first // 2. Generate backfill migration code // 3. Provide verification query // 4. Guide making field required after backfill ``` ## Best Practices Enforced ### Security - ✅ All public functions validate arguments - ✅ Authentication checks with `ctx.auth.getUserIdentity()` - ✅ Authorization checks for resource ownership - ✅ Only internal functions can be scheduled ### Performance - ✅ Use `.withIndex()` instead of `.filter()` - ✅ Index all foreign keys - ✅ Remove redundant indexes - ✅ Batch large operations ### Code Quality - ✅ All promises awaited (no floating promises) - ✅ Logic in plain TypeScript functions - ✅ Thin query/mutation/action wrappers - ✅ Clear error messages ### Schema Design - ✅ Flat, relational structure - ✅ IDs for relationships (not nested objects) - ✅ Arrays only for small, bounded collections - ✅ Proper validator types ## Troubleshooting ### Hooks Not Running Make sure hook scripts are executable: ```bash chmod +x scripts/*.sh ``` ### MCP Server Not Connecting Verify environment variables are set: ```bash echo $CONVEX_DEPLOYMENT echo $CONVEX_DEPLOY_KEY ``` Get your deploy key from the [Convex Dashboard](https://dashboard.convex.dev). ### Schema Codegen Fails Ensure you have Convex installed: ```bash npm install convex # or npm install convex@latest ``` ## Cursor plugin mechanism status Convex ships an end-of-turn "verify before you say you're done" mechanism across the coding agents it supports, but the _strength_ of that mechanism depends on what each agent's plugin format actually offers: | Agent | Mechanism | Enforcement | | --- | --- | --- | | Claude Code | `Stop` hook | Can block: the hook can require the agent keep working before the turn is allowed to end. | | Codex | MCP server leg (`fix_errors_automatically`) | Blocking tool call: the agent's own idle loop calls a tool that blocks until a real event (including a compile error) fires. | | **Cursor** | `stop` hook → `followup_message` (`scripts/stop-verify.sh`) | **Not blocking.** Cursor's `stop` hook cannot prevent a turn from ending; it can only auto-submit a follow-up message (capped at `loop_limit: 2` here) asking the agent to fix what the hook found. A user can still walk away from a broken build if they ignore the follow-up or the loop limit is hit. | This is a real, Cursor-native mechanism — not just the static SELF-VERIFY RULE text in `rules/quickstart.mdc` — but it is a retry-loop, not a gate. Cursor's plugin format has no hook that blocks turn completion the way Claude Code's `Stop` hook does (confirmed against [Cursor's hooks documentation](https://cursor.com/docs/hooks): the `stop` event's own docs state it fires "when the agent loop ends" and its only output field is the informational/loop-triggering `followup_message` — there is no `permission`/block field on that event, unlike `beforeShellExecution` which this plugin already uses to hard-deny bad `git commit`s). If Cursor ships a blocking end-of-turn hook in the future, this is the file to upgrade (`scripts/stop-verify.sh` + the `stop` entry in `hooks.json`). ## Learn More - [Convex Documentation](https://docs.convex.dev) - [Convex Best Practices](https://docs.convex.dev/understanding/best-practices/) - [Schema Design Guide](https://docs.convex.dev/database/schemas) - [Authentication Guide](https://docs.convex.dev/auth) - [Convex GitHub](https://github.com/convex) ## Contributing This is the official Convex plugin maintained by the Convex team. For issues or suggestions: - Report issues on [GitHub](https://github.com/convex/convex-agent-plugins) - Join the [Convex Discord](https://convex.dev/community) - Contact: support@convex.dev ## Privacy & data This plugin connects to Convex services. See the [Convex privacy policy](https://convex.dev/legal/privacy) for full details and your rights. ### Usage telemetry This plugin sends no usage telemetry. ### Adding capabilities (only when you run `/add`) The `/add` command downloads a capability catalog and setup scripts from the Convex scaffolding service, and runs those scripts. The service logs each script download as an anonymous event. If you don't run `/add`, the plugin sends nothing to these services. ## License MIT License - See LICENSE file for details --- Built with ❤️ by the [Convex](https://convex.dev) team DetailsTypeAgent skillsTopicSecurity & identityPublisherget-convexSourceskillsshCategoryToolsStars117Copies (forks)13Proposed changes2Last update2026-10-29T16:51:30ZProject statusActiveLanguageShellLicenseMITAdded2026-10-07 05:21:37Updated2026-11-02 17:32:55Source idget-convex/convex-agent-plugins/function-creatorMoreMore agent skills on Security & identityAll from get-convexA–Z index
