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admin b723e2bd7d Reorganize: Move all skills to skills/ folder

- Created skills/ directory
- Moved 272 skills to skills/ subfolder
- Kept agents/ at root level
- Kept installation scripts and docs at root level

Repository structure:
- skills/           - All 272 skills from skills.sh
- agents/           - Agent definitions
- *.sh, *.ps1       - Installation scripts
- README.md, etc.   - Documentation

Co-Authored-By: Claude <noreply@anthropic.com>

2026-01-23 18:05:17 +00:00

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Convex Migrations

Evolve your Convex database schema safely with patterns for adding fields, backfilling data, removing deprecated fields, and maintaining zero-downtime deployments.

Documentation Sources

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

Primary: https://docs.convex.dev/database/schemas
Schema Overview: https://docs.convex.dev/database
Migration Patterns: https://stack.convex.dev/migrate-data-postgres-to-convex
For broader context: https://docs.convex.dev/llms.txt

Instructions

Migration Philosophy

Convex handles schema evolution differently than traditional databases:

No explicit migration files or commands
Schema changes deploy instantly with npx convex dev
Existing data is not automatically transformed
Use optional fields and backfill mutations for safe migrations

Adding New Fields

Start with optional fields, then backfill:

// Step 1: Add optional field to schema
// convex/schema.ts
import { defineSchema, defineTable } from "convex/server";
import { v } from "convex/values";

export default defineSchema({
  users: defineTable({
    name: v.string(),
    email: v.string(),
    // New field - start as optional
    avatarUrl: v.optional(v.string()),
  }),
});

// Step 2: Update code to handle both cases
// convex/users.ts
import { query } from "./_generated/server";
import { v } from "convex/values";

export const getUser = query({
  args: { userId: v.id("users") },
  returns: v.union(
    v.object({
      _id: v.id("users"),
      name: v.string(),
      email: v.string(),
      avatarUrl: v.union(v.string(), v.null()),
    }),
    v.null()
  ),
  handler: async (ctx, args) => {
    const user = await ctx.db.get(args.userId);
    if (!user) return null;

    return {
      _id: user._id,
      name: user.name,
      email: user.email,
      // Handle missing field gracefully
      avatarUrl: user.avatarUrl ?? null,
    };
  },
});

// Step 3: Backfill existing documents
// convex/migrations.ts
import { internalMutation } from "./_generated/server";
import { internal } from "./_generated/api";
import { v } from "convex/values";

const BATCH_SIZE = 100;

export const backfillAvatarUrl = internalMutation({
  args: {
    cursor: v.optional(v.string()),
  },
  returns: v.object({
    processed: v.number(),
    hasMore: v.boolean(),
  }),
  handler: async (ctx, args) => {
    const result = await ctx.db
      .query("users")
      .paginate({ numItems: BATCH_SIZE, cursor: args.cursor ?? null });

    let processed = 0;
    for (const user of result.page) {
      // Only update if field is missing
      if (user.avatarUrl === undefined) {
        await ctx.db.patch(user._id, {
          avatarUrl: generateDefaultAvatar(user.name),
        });
        processed++;
      }
    }

    // Schedule next batch if needed
    if (!result.isDone) {
      await ctx.scheduler.runAfter(0, internal.migrations.backfillAvatarUrl, {
        cursor: result.continueCursor,
      });
    }

    return {
      processed,
      hasMore: !result.isDone,
    };
  },
});

function generateDefaultAvatar(name: string): string {
  return `https://api.dicebear.com/7.x/initials/svg?seed=${encodeURIComponent(name)}`;
}

// Step 4: After backfill completes, make field required
// convex/schema.ts
export default defineSchema({
  users: defineTable({
    name: v.string(),
    email: v.string(),
    avatarUrl: v.string(), // Now required
  }),
});

Removing Fields

Remove field usage before removing from schema:

// Step 1: Stop using the field in queries and mutations
// Mark as deprecated in code comments

// Step 2: Remove field from schema (make optional first if needed)
// convex/schema.ts
export default defineSchema({
  posts: defineTable({
    title: v.string(),
    content: v.string(),
    authorId: v.id("users"),
    // legacyField: v.optional(v.string()), // Remove this line
  }),
});

// Step 3: Optionally clean up existing data
// convex/migrations.ts
export const removeDeprecatedField = internalMutation({
  args: {
    cursor: v.optional(v.string()),
  },
  returns: v.null(),
  handler: async (ctx, args) => {
    const result = await ctx.db
      .query("posts")
      .paginate({ numItems: 100, cursor: args.cursor ?? null });

    for (const post of result.page) {
      // Use replace to remove the field entirely
      const { legacyField, ...rest } = post as typeof post & { legacyField?: string };
      if (legacyField !== undefined) {
        await ctx.db.replace(post._id, rest);
      }
    }

    if (!result.isDone) {
      await ctx.scheduler.runAfter(0, internal.migrations.removeDeprecatedField, {
        cursor: result.continueCursor,
      });
    }

    return null;
  },
});

Renaming Fields

Renaming requires copying data to new field, then removing old:

// Step 1: Add new field as optional
// convex/schema.ts
export default defineSchema({
  users: defineTable({
    userName: v.string(), // Old field
    displayName: v.optional(v.string()), // New field
  }),
});

// Step 2: Update code to read from new field with fallback
export const getUser = query({
  args: { userId: v.id("users") },
  returns: v.object({
    _id: v.id("users"),
    displayName: v.string(),
  }),
  handler: async (ctx, args) => {
    const user = await ctx.db.get(args.userId);
    if (!user) throw new Error("User not found");

    return {
      _id: user._id,
      // Read new field, fall back to old
      displayName: user.displayName ?? user.userName,
    };
  },
});

// Step 3: Backfill to copy data
export const backfillDisplayName = internalMutation({
  args: { cursor: v.optional(v.string()) },
  returns: v.null(),
  handler: async (ctx, args) => {
    const result = await ctx.db
      .query("users")
      .paginate({ numItems: 100, cursor: args.cursor ?? null });

    for (const user of result.page) {
      if (user.displayName === undefined) {
        await ctx.db.patch(user._id, {
          displayName: user.userName,
        });
      }
    }

    if (!result.isDone) {
      await ctx.scheduler.runAfter(0, internal.migrations.backfillDisplayName, {
        cursor: result.continueCursor,
      });
    }

    return null;
  },
});

// Step 4: After backfill, update schema to make new field required
// and remove old field
export default defineSchema({
  users: defineTable({
    // userName removed
    displayName: v.string(),
  }),
});

Adding Indexes

Add indexes before using them in queries:

// Step 1: Add index to schema
// convex/schema.ts
export default defineSchema({
  posts: defineTable({
    title: v.string(),
    authorId: v.id("users"),
    publishedAt: v.optional(v.number()),
    status: v.string(),
  })
    .index("by_author", ["authorId"])
    // New index
    .index("by_status_and_published", ["status", "publishedAt"]),
});

// Step 2: Deploy schema change
// Run: npx convex dev

// Step 3: Now use the index in queries
export const getPublishedPosts = query({
  args: {},
  returns: v.array(v.object({
    _id: v.id("posts"),
    title: v.string(),
    publishedAt: v.number(),
  })),
  handler: async (ctx) => {
    const posts = await ctx.db
      .query("posts")
      .withIndex("by_status_and_published", (q) =>
        q.eq("status", "published")
      )
      .order("desc")
      .take(10);

    return posts
      .filter((p) => p.publishedAt !== undefined)
      .map((p) => ({
        _id: p._id,
        title: p.title,
        publishedAt: p.publishedAt!,
      }));
  },
});

Changing Field Types

Type changes require careful migration:

// Example: Change from string to number for a "priority" field

// Step 1: Add new field with new type
// convex/schema.ts
export default defineSchema({
  tasks: defineTable({
    title: v.string(),
    priority: v.string(), // Old: "low", "medium", "high"
    priorityLevel: v.optional(v.number()), // New: 1, 2, 3
  }),
});

// Step 2: Backfill with type conversion
export const migratePriorityToNumber = internalMutation({
  args: { cursor: v.optional(v.string()) },
  returns: v.null(),
  handler: async (ctx, args) => {
    const result = await ctx.db
      .query("tasks")
      .paginate({ numItems: 100, cursor: args.cursor ?? null });

    const priorityMap: Record<string, number> = {
      low: 1,
      medium: 2,
      high: 3,
    };

    for (const task of result.page) {
      if (task.priorityLevel === undefined) {
        await ctx.db.patch(task._id, {
          priorityLevel: priorityMap[task.priority] ?? 1,
        });
      }
    }

    if (!result.isDone) {
      await ctx.scheduler.runAfter(0, internal.migrations.migratePriorityToNumber, {
        cursor: result.continueCursor,
      });
    }

    return null;
  },
});

// Step 3: Update code to use new field
export const getTask = query({
  args: { taskId: v.id("tasks") },
  returns: v.object({
    _id: v.id("tasks"),
    title: v.string(),
    priorityLevel: v.number(),
  }),
  handler: async (ctx, args) => {
    const task = await ctx.db.get(args.taskId);
    if (!task) throw new Error("Task not found");

    const priorityMap: Record<string, number> = {
      low: 1,
      medium: 2,
      high: 3,
    };

    return {
      _id: task._id,
      title: task.title,
      priorityLevel: task.priorityLevel ?? priorityMap[task.priority] ?? 1,
    };
  },
});

// Step 4: After backfill, update schema
export default defineSchema({
  tasks: defineTable({
    title: v.string(),
    // priority field removed
    priorityLevel: v.number(),
  }),
});

Migration Runner Pattern

Create a reusable migration system:

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

export default defineSchema({
  migrations: defineTable({
    name: v.string(),
    startedAt: v.number(),
    completedAt: v.optional(v.number()),
    status: v.union(
      v.literal("running"),
      v.literal("completed"),
      v.literal("failed")
    ),
    error: v.optional(v.string()),
    processed: v.number(),
  }).index("by_name", ["name"]),

  // Your other tables...
});

// convex/migrations.ts
import { internalMutation, internalQuery } from "./_generated/server";
import { internal } from "./_generated/api";
import { v } from "convex/values";

// Check if migration has run
export const hasMigrationRun = internalQuery({
  args: { name: v.string() },
  returns: v.boolean(),
  handler: async (ctx, args) => {
    const migration = await ctx.db
      .query("migrations")
      .withIndex("by_name", (q) => q.eq("name", args.name))
      .first();
    return migration?.status === "completed";
  },
});

// Start a migration
export const startMigration = internalMutation({
  args: { name: v.string() },
  returns: v.id("migrations"),
  handler: async (ctx, args) => {
    // Check if already exists
    const existing = await ctx.db
      .query("migrations")
      .withIndex("by_name", (q) => q.eq("name", args.name))
      .first();

    if (existing) {
      if (existing.status === "completed") {
        throw new Error(`Migration ${args.name} already completed`);
      }
      if (existing.status === "running") {
        throw new Error(`Migration ${args.name} already running`);
      }
      // Reset failed migration
      await ctx.db.patch(existing._id, {
        status: "running",
        startedAt: Date.now(),
        error: undefined,
        processed: 0,
      });
      return existing._id;
    }

    return await ctx.db.insert("migrations", {
      name: args.name,
      startedAt: Date.now(),
      status: "running",
      processed: 0,
    });
  },
});

// Update migration progress
export const updateMigrationProgress = internalMutation({
  args: {
    migrationId: v.id("migrations"),
    processed: v.number(),
  },
  returns: v.null(),
  handler: async (ctx, args) => {
    const migration = await ctx.db.get(args.migrationId);
    if (!migration) return null;

    await ctx.db.patch(args.migrationId, {
      processed: migration.processed + args.processed,
    });

    return null;
  },
});

// Complete a migration
export const completeMigration = internalMutation({
  args: { migrationId: v.id("migrations") },
  returns: v.null(),
  handler: async (ctx, args) => {
    await ctx.db.patch(args.migrationId, {
      status: "completed",
      completedAt: Date.now(),
    });
    return null;
  },
});

// Fail a migration
export const failMigration = internalMutation({
  args: {
    migrationId: v.id("migrations"),
    error: v.string(),
  },
  returns: v.null(),
  handler: async (ctx, args) => {
    await ctx.db.patch(args.migrationId, {
      status: "failed",
      error: args.error,
    });
    return null;
  },
});

// convex/migrations/addUserTimestamps.ts
import { internalMutation } from "../_generated/server";
import { internal } from "../_generated/api";
import { v } from "convex/values";

const MIGRATION_NAME = "add_user_timestamps_v1";
const BATCH_SIZE = 100;

export const run = internalMutation({
  args: {
    migrationId: v.optional(v.id("migrations")),
    cursor: v.optional(v.string()),
  },
  returns: v.null(),
  handler: async (ctx, args) => {
    // Initialize migration on first run
    let migrationId = args.migrationId;
    if (!migrationId) {
      const hasRun = await ctx.runQuery(internal.migrations.hasMigrationRun, {
        name: MIGRATION_NAME,
      });
      if (hasRun) {
        console.log(`Migration ${MIGRATION_NAME} already completed`);
        return null;
      }
      migrationId = await ctx.runMutation(internal.migrations.startMigration, {
        name: MIGRATION_NAME,
      });
    }

    try {
      const result = await ctx.db
        .query("users")
        .paginate({ numItems: BATCH_SIZE, cursor: args.cursor ?? null });

      let processed = 0;
      for (const user of result.page) {
        if (user.createdAt === undefined) {
          await ctx.db.patch(user._id, {
            createdAt: user._creationTime,
            updatedAt: user._creationTime,
          });
          processed++;
        }
      }

      // Update progress
      await ctx.runMutation(internal.migrations.updateMigrationProgress, {
        migrationId,
        processed,
      });

      // Continue or complete
      if (!result.isDone) {
        await ctx.scheduler.runAfter(0, internal.migrations.addUserTimestamps.run, {
          migrationId,
          cursor: result.continueCursor,
        });
      } else {
        await ctx.runMutation(internal.migrations.completeMigration, {
          migrationId,
        });
        console.log(`Migration ${MIGRATION_NAME} completed`);
      }
    } catch (error) {
      await ctx.runMutation(internal.migrations.failMigration, {
        migrationId,
        error: String(error),
      });
      throw error;
    }

    return null;
  },
});

Examples

Schema with Migration Support

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

export default defineSchema({
  // Migration tracking
  migrations: defineTable({
    name: v.string(),
    startedAt: v.number(),
    completedAt: v.optional(v.number()),
    status: v.union(
      v.literal("running"),
      v.literal("completed"),
      v.literal("failed")
    ),
    error: v.optional(v.string()),
    processed: v.number(),
  }).index("by_name", ["name"]),

  // Users table with evolved schema
  users: defineTable({
    // Original fields
    name: v.string(),
    email: v.string(),
    
    // Added in migration v1
    createdAt: v.optional(v.number()),
    updatedAt: v.optional(v.number()),
    
    // Added in migration v2
    avatarUrl: v.optional(v.string()),
    
    // Added in migration v3
    settings: v.optional(v.object({
      theme: v.string(),
      notifications: v.boolean(),
    })),
  })
    .index("by_email", ["email"])
    .index("by_createdAt", ["createdAt"]),

  // Posts table with indexes for common queries
  posts: defineTable({
    title: v.string(),
    content: v.string(),
    authorId: v.id("users"),
    status: v.union(
      v.literal("draft"),
      v.literal("published"),
      v.literal("archived")
    ),
    publishedAt: v.optional(v.number()),
    createdAt: v.number(),
    updatedAt: v.number(),
  })
    .index("by_author", ["authorId"])
    .index("by_status", ["status"])
    .index("by_author_and_status", ["authorId", "status"])
    .index("by_publishedAt", ["publishedAt"]),
});

Best Practices

Never run npx convex deploy unless explicitly instructed
Never run any git commands unless explicitly instructed
Always start with optional fields when adding new data
Backfill data in batches to avoid timeouts
Test migrations on development before production
Keep track of completed migrations to avoid re-running
Update code to handle both old and new data during transition
Remove deprecated fields only after all code stops using them
Use pagination for large datasets
Add appropriate indexes before running queries on new fields

Common Pitfalls

Making new fields required immediately - Breaks existing documents
Not handling undefined values - Causes runtime errors
Large batch sizes - Causes function timeouts
Forgetting to update indexes - Queries fail or perform poorly
Running migrations without tracking - May run multiple times
Removing fields before code update - Breaks existing functionality
Not testing on development - Production data issues

References

Convex Documentation: https://docs.convex.dev/
Convex LLMs.txt: https://docs.convex.dev/llms.txt
Schemas: https://docs.convex.dev/database/schemas
Database Overview: https://docs.convex.dev/database
Migration Patterns: https://stack.convex.dev/migrate-data-postgres-to-convex

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