Convex Component Authoring

Create self-contained, reusable Convex components with proper isolation, exports, and dependency management for sharing across projects.

Documentation Sources

Before implementing, do not assume; fetch the latest documentation:

•Primary: https://docs.convex.dev/components
•Component Authoring: https://docs.convex.dev/components/authoring
•For broader context: https://docs.convex.dev/llms.txt

Instructions

What Are Convex Components?

Convex components are self-contained packages that include:

•Database tables (isolated from the main app)
•Functions (queries, mutations, actions)
•TypeScript types and validators
•Optional frontend hooks

Component Structure

code

my-convex-component/
├── package.json
├── tsconfig.json
├── README.md
├── src/
│   ├── index.ts           # Main exports
│   ├── component.ts       # Component definition
│   ├── schema.ts          # Component schema
│   └── functions/
│       ├── queries.ts
│       ├── mutations.ts
│       └── actions.ts
└── convex.config.ts       # Component configuration

Creating a Component

1. Component Configuration

typescript

// convex.config.ts
import { defineComponent } from "convex/server";

export default defineComponent("myComponent");

2. Component Schema

typescript

// src/schema.ts
import { defineSchema, defineTable } from "convex/server";
import { v } from "convex/values";

export default defineSchema({
  // Tables are isolated to this component
  items: defineTable({
    name: v.string(),
    data: v.any(),
    createdAt: v.number(),
  }).index("by_name", ["name"]),

  config: defineTable({
    key: v.string(),
    value: v.any(),
  }).index("by_key", ["key"]),
});

3. Component Definition

typescript

// src/component.ts
import { defineComponent, ComponentDefinition } from "convex/server";
import schema from "./schema";
import * as queries from "./functions/queries";
import * as mutations from "./functions/mutations";

const component = defineComponent("myComponent", {
  schema,
  functions: {
    ...queries,
    ...mutations,
  },
});

export default component;

4. Component Functions

typescript

// src/functions/queries.ts
import { query } from "../_generated/server";
import { v } from "convex/values";

export const list = query({
  args: {
    limit: v.optional(v.number()),
  },
  returns: v.array(
    v.object({
      _id: v.id("items"),
      name: v.string(),
      data: v.any(),
      createdAt: v.number(),
    }),
  ),
  handler: async (ctx, args) => {
    return await ctx.db
      .query("items")
      .order("desc")
      .take(args.limit ?? 10);
  },
});

export const get = query({
  args: { name: v.string() },
  returns: v.union(
    v.object({
      _id: v.id("items"),
      name: v.string(),
      data: v.any(),
    }),
    v.null(),
  ),
  handler: async (ctx, args) => {
    return await ctx.db
      .query("items")
      .withIndex("by_name", (q) => q.eq("name", args.name))
      .unique();
  },
});

typescript

// src/functions/mutations.ts
import { mutation } from "../_generated/server";
import { v } from "convex/values";

export const create = mutation({
  args: {
    name: v.string(),
    data: v.any(),
  },
  returns: v.id("items"),
  handler: async (ctx, args) => {
    return await ctx.db.insert("items", {
      name: args.name,
      data: args.data,
      createdAt: Date.now(),
    });
  },
});

export const update = mutation({
  args: {
    id: v.id("items"),
    data: v.any(),
  },
  returns: v.null(),
  handler: async (ctx, args) => {
    await ctx.db.patch(args.id, { data: args.data });
    return null;
  },
});

export const remove = mutation({
  args: { id: v.id("items") },
  returns: v.null(),
  handler: async (ctx, args) => {
    await ctx.db.delete(args.id);
    return null;
  },
});

5. Main Exports

typescript

// src/index.ts
export { default as component } from "./component";
export * from "./functions/queries";
export * from "./functions/mutations";

// Export types for consumers
export type { Id } from "./_generated/dataModel";

Using a Component

typescript

// In the consuming app's convex/convex.config.ts
import { defineApp } from "convex/server";
import myComponent from "my-convex-component";

const app = defineApp();

app.use(myComponent, { name: "myComponent" });

export default app;

typescript

// In the consuming app's code
import { useQuery, useMutation } from "convex/react";
import { api } from "../convex/_generated/api";

function MyApp() {
  // Access component functions through the app's API
  const items = useQuery(api.myComponent.list, { limit: 10 });
  const createItem = useMutation(api.myComponent.create);

  return (
    <div>
      {items?.map((item) => (
        <div key={item._id}>{item.name}</div>
      ))}
      <button onClick={() => createItem({ name: "New", data: {} })}>
        Add Item
      </button>
    </div>
  );
}

Component Configuration Options

typescript

// convex/convex.config.ts
import { defineApp } from "convex/server";
import myComponent from "my-convex-component";

const app = defineApp();

// Basic usage
app.use(myComponent);

// With custom name
app.use(myComponent, { name: "customName" });

// Multiple instances
app.use(myComponent, { name: "instance1" });
app.use(myComponent, { name: "instance2" });

export default app;

Providing Component Hooks

typescript

// src/hooks.ts
import { useQuery, useMutation } from "convex/react";
import { FunctionReference } from "convex/server";

// Type-safe hooks for component consumers
export function useMyComponent(api: {
  list: FunctionReference<"query">;
  create: FunctionReference<"mutation">;
}) {
  const items = useQuery(api.list, {});
  const createItem = useMutation(api.create);

  return {
    items,
    createItem,
    isLoading: items === undefined,
  };
}

Publishing a Component

package.json

json

{
  "name": "my-convex-component",
  "version": "1.0.0",
  "description": "A reusable Convex component",
  "main": "dist/index.js",
  "types": "dist/index.d.ts",
  "files": ["dist", "convex.config.ts"],
  "scripts": {
    "build": "tsc",
    "prepublishOnly": "npm run build"
  },
  "peerDependencies": {
    "convex": "^1.0.0"
  },
  "devDependencies": {
    "convex": "^1.17.0",
    "typescript": "^5.0.0"
  },
  "keywords": ["convex", "component"]
}

tsconfig.json

json

{
  "compilerOptions": {
    "target": "ES2020",
    "module": "ESNext",
    "moduleResolution": "bundler",
    "declaration": true,
    "outDir": "dist",
    "strict": true,
    "esModuleInterop": true,
    "skipLibCheck": true
  },
  "include": ["src/**/*"],
  "exclude": ["node_modules", "dist"]
}

Examples

Rate Limiter Component

typescript

// rate-limiter/src/schema.ts
import { defineSchema, defineTable } from "convex/server";
import { v } from "convex/values";

export default defineSchema({
  requests: defineTable({
    key: v.string(),
    timestamp: v.number(),
  })
    .index("by_key", ["key"])
    .index("by_key_and_time", ["key", "timestamp"]),
});

typescript

// rate-limiter/src/functions/mutations.ts
import { mutation } from "../_generated/server";
import { v } from "convex/values";

export const checkLimit = mutation({
  args: {
    key: v.string(),
    limit: v.number(),
    windowMs: v.number(),
  },
  returns: v.object({
    allowed: v.boolean(),
    remaining: v.number(),
    resetAt: v.number(),
  }),
  handler: async (ctx, args) => {
    const now = Date.now();
    const windowStart = now - args.windowMs;

    // Clean old entries
    const oldEntries = await ctx.db
      .query("requests")
      .withIndex("by_key_and_time", (q) => q.eq("key", args.key).lt("timestamp", windowStart))
      .collect();

    for (const entry of oldEntries) {
      await ctx.db.delete(entry._id);
    }

    // Count current window
    const currentRequests = await ctx.db
      .query("requests")
      .withIndex("by_key", (q) => q.eq("key", args.key))
      .collect();

    const remaining = Math.max(0, args.limit - currentRequests.length);
    const allowed = remaining > 0;

    if (allowed) {
      await ctx.db.insert("requests", {
        key: args.key,
        timestamp: now,
      });
    }

    const oldestRequest = currentRequests[0];
    const resetAt = oldestRequest ? oldestRequest.timestamp + args.windowMs : now + args.windowMs;

    return { allowed, remaining: remaining - (allowed ? 1 : 0), resetAt };
  },
});

typescript

// Usage in consuming app
import { useMutation } from "convex/react";
import { api } from "../convex/_generated/api";

function useRateLimitedAction() {
  const checkLimit = useMutation(api.rateLimiter.checkLimit);

  return async (action: () => Promise<void>) => {
    const result = await checkLimit({
      key: "user-action",
      limit: 10,
      windowMs: 60000,
    });

    if (!result.allowed) {
      throw new Error(`Rate limited. Try again at ${new Date(result.resetAt)}`);
    }

    await action();
  };
}

Best Practices

•Never run npx convex deploy unless explicitly instructed
•Never run any git commands unless explicitly instructed
•Keep component tables isolated (don't reference main app tables)
•Export clear TypeScript types for consumers
•Document all public functions and their arguments
•Use semantic versioning for component releases
•Include comprehensive README with examples
•Test components in isolation before publishing

Common Pitfalls

•Cross-referencing tables - Component tables should be self-contained
•Missing type exports - Export all necessary types
•Hardcoded configuration - Use component options for customization
•No versioning - Follow semantic versioning
•Poor documentation - Document all public APIs

References

•Convex Documentation: https://docs.convex.dev/
•Convex LLMs.txt: https://docs.convex.dev/llms.txt
•Components: https://docs.convex.dev/components
•Component Authoring: https://docs.convex.dev/components/authoring