---

name: cube description: >- Cube is an open-source semantic layer that sits between a data warehouse and analytics applications and serves governed metrics over REST, GraphQL and SQL APIs. Use when a user asks to define cubes, measures and dimensions, add pre-aggregations, build a metrics API or embedded analytics, set up multi-tenant row-level security, or query Cube from React or the REST API. license: Apache-2.0 compatibility: Docker (cubejs/cube image) or Node.js; a SQL data source such as Postgres, BigQuery or Snowflake metadata: author: terminal-skills version: "1.1.0" repository: https://github.com/cube-js/cube category: data-ai tags:

• semantic-layer
• analytics
• api
• sql
• metrics

---

Cube — Semantic Layer for Analytics

Overview

Cube (Cube Core is the self-hosted open-source part; Cube Cloud is the hosted platform) is a semantic layer: you define metrics once as code (cubes, measures, dimensions, joins, pre-aggregations), and Cube serves them to apps over a REST (JSON) API, GraphQL API and a Postgres-compatible SQL API, with caching and access control. Current release is 1.7.x (October 2026). Docs: https://docs.cube.dev.

Instructions

Data Modeling

Data model files live in model/cubes/ and model/views/ (inside the project folder mounted at /cube/conf). YAML is the format the docs recommend; JavaScript works too and is used below. Reference members of the same cube as CUBE.measure in pre_aggregations.

// model/cubes/Orders.js — Orders cube with measures and dimensions
cube(`Orders`, {
  sql_table: `public.orders`,

  // Pre-aggregation: materialized rollup kept in Cube Store
  pre_aggregations: {
    daily_revenue: {
      measures: [CUBE.revenue, CUBE.count],
      dimensions: [CUBE.status],
      time_dimension: CUBE.created_at,
      granularity: `day`,
      refresh_key: { every: `1 hour` },
    },
  },

  joins: {
    Users: { relationship: `many_to_one`, sql: `${CUBE}.user_id = ${Users}.id` },
  },

  measures: {
    count: { type: `count` },
    revenue: { type: `sum`, sql: `amount`, format: `currency` },
    revenue_per_user: { type: `number`, sql: `${revenue} / NULLIF(${Users.count}, 0)`, format: `currency` },
    // Rolling window: trailing 7-day sum (used with a time dimension)
    revenue_7d: { type: `sum`, sql: `amount`, rolling_window: { trailing: `7 day` } },
  },

  dimensions: {
    id: { type: `number`, sql: `id`, primary_key: true },
    status: { type: `string`, sql: `status` },
    tenant_id: { type: `string`, sql: `tenant_id` },
    created_at: { type: `time`, sql: `created_at` },
  },

  // Segments are named, reusable filters (queried as "Orders.completed")
  segments: {
    completed: { sql: `${CUBE}.status = 'completed'` },
  },
});

// model/cubes/Users.js — Users cube (condensed)
cube(`Users`, {
  sql_table: `public.users`,
  measures: {
    count: { type: `count` },
    active_count: { type: `count`, filters: [{ sql: `${CUBE}.last_login_at > NOW() - INTERVAL '30 days'` }] },
  },
  dimensions: {
    id: { type: `number`, sql: `id`, primary_key: true },
    plan: { type: `string`, sql: `plan` },
    country: { type: `string`, sql: `country` },
    created_at: { type: `time`, sql: `created_at` },
  },
});

REST API

Cube Core serves the REST API under /cubejs-api (configurable with base_path). Send a JWT signed with CUBEJS_API_SECRET in the Authorization header (the token carries the security context). Endpoints: /cubejs-api/v1/load (query), /v1/meta (model metadata), /v1/sql (generated SQL).

// src/analytics/cube-client.ts — Query the Cube REST API
const CUBE_API_URL = process.env.CUBE_API_URL!;
const CUBE_API_TOKEN = process.env.CUBE_API_TOKEN!;

type CubeQuery = Record<string, unknown>; // measures, dimensions, timeDimensions, filters, order, limit

async function cubeQuery(query: CubeQuery) {
  const response = await fetch(`${CUBE_API_URL}/cubejs-api/v1/load`, {   // CUBE_API_URL=http://localhost:4000
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      Authorization: CUBE_API_TOKEN,   // JWT; "Bearer <jwt>" is also accepted
    },
    body: JSON.stringify({ query }),
  });

  const result = await response.json();
  // Long queries answer {"error": "Continue wait"}: repeat the request until data arrives
  if (result.error === "Continue wait") return cubeQuery(query);
  if (result.error) throw new Error(result.error);
  return result.data;
}

// Example: Get monthly revenue by order status
const monthlyRevenue = await cubeQuery({
  measures: ["Orders.revenue", "Orders.count"],
  dimensions: ["Orders.status"],
  timeDimensions: [{
    dimension: "Orders.created_at",
    granularity: "month",
    dateRange: "Last 6 months",
  }],
  order: { "Orders.revenue": "desc" },
  limit: 100,
});

// Example: active users by plan
const activeByPlan = await cubeQuery({
  measures: ["Users.active_count"],
  dimensions: ["Users.plan"],
  filters: [{ member: "Users.plan", operator: "equals", values: ["pro", "enterprise"] }],
});

JavaScript SDK (React)

Build analytics UIs with @cubejs-client/core and @cubejs-client/react (both 1.7.x). Wrap the app in CubeProvider:

// src/main.tsx
import cube from "@cubejs-client/core";
import { CubeProvider } from "@cubejs-client/react";
const cubeApi = cube(process.env.CUBE_TOKEN!, { apiUrl: "http://localhost:4000/cubejs-api/v1" });
// <CubeProvider cubeApi={cubeApi}><App /></CubeProvider>

// src/components/RevenueChart.tsx — React component using Cube
import { useCubeQuery } from "@cubejs-client/react";
import { LineChart, Line, XAxis, YAxis, Tooltip, ResponsiveContainer } from "recharts";

export function RevenueChart({ dateRange = "Last 6 months" }) {
  const { resultSet, isLoading, error } = useCubeQuery({
    measures: ["Orders.revenue"],
    timeDimensions: [{
      dimension: "Orders.created_at",
      granularity: "month",
      dateRange,
    }],
  });

  if (isLoading) return <div>Loading...</div>;
  if (error) return <div>Error: {error.message}</div>;

  const data = resultSet?.chartPivot() ?? [];

  return (
    <ResponsiveContainer width="100%" height={300}>
      <LineChart data={data}>
        <XAxis dataKey="x" />
        <YAxis />
        <Tooltip formatter={(value: number) => `${value.toLocaleString()}`} />
        <Line type="monotone" dataKey="Orders.revenue" stroke="#6366f1" strokeWidth={2} />
      </LineChart>
    </ResponsiveContainer>
  );
}

Access Control

Verified JWT claims become the securityContext. For multi-tenancy, scope queries and compiled models per tenant in cube.js (or cube.py):

// cube.js — security context configuration
module.exports = {
  // One compiled data model + cache per tenant
  contextToAppId: ({ securityContext }) => `CUBE_APP_${securityContext.tenant_id}`,

  // Called on every request: add a row-level filter
  queryRewrite: (query, { securityContext }) => {
    if (!securityContext.tenant_id) {
      throw new Error("tenant_id is required in the security context");
    }
    query.filters = query.filters || [];
    query.filters.push({
      member: "Orders.tenant_id",
      operator: "equals",
      values: [securityContext.tenant_id],
    });
    return query;
  },
};

Cube also supports declarative access_policy blocks on cubes and views (group-scoped member_level and row_level rules, plus masking); when policies exist for some groups, every other group is denied:

# model/cubes/orders.yml (excerpt)
    access_policy:
      - group: finance
        member_level:
          includes: "*"
      - group: support
        member_level:
          includes: [count, status]
        row_level:
          filters:
            - member: status
              operator: equals
              values: [completed]

If you use securityContext in contextToAppId, also set scheduledRefreshContexts so pre-aggregations refresh for each tenant.

Installation

The documented way to start is Docker Compose in an empty project folder:

# docker-compose.yml
services:
  cube:
    image: cubejs/cube:latest        # pin e.g. cubejs/cube:v1.7.50 in production
    ports:
      - 4000:4000                    # REST/GraphQL APIs and Playground
      - 15432:15432                  # Postgres-compatible SQL API
    environment:
      - CUBEJS_DEV_MODE=true         # local only, see warning below
    volumes:
      - .:/cube/conf

docker compose up -d
# Open http://localhost:4000, pick your database in the wizard (it writes .env), then "Generate Data Model" (YAML or JavaScript)

Database settings go in .env: CUBEJS_DB_TYPE=postgres, CUBEJS_DB_HOST, CUBEJS_DB_NAME, CUBEJS_DB_USER, CUBEJS_DB_PASS, and CUBEJS_API_SECRET (random string used to sign and verify API JWTs). The npx cubejs-cli create scaffold still exists but the docs no longer lead with it. For production, run an API instance, a refresh worker and Cube Store (router plus workers) as in https://docs.cube.dev/cube-core/deployment.

CUBEJS_DEV_MODE=true turns off authentication on the REST and GraphQL APIs and exposes Playground with ready-made tokens. Use it only on your own machine; set CUBEJS_DEV_MODE=false anywhere else.

Examples

Example 1: Add a metrics API on top of an orders table

User request:

We have orders and users tables in Postgres. Give our frontend an API for monthly revenue by order status, with a daily rollup so it's fast.

The agent creates model/cubes/Orders.js and Users.js as above (primary keys, a many_to_one join, revenue and count measures, a daily_revenue pre-aggregation), starts Cube with docker compose up -d, and checks the model in Playground. It then verifies the endpoint with a signed token:

curl -G http://localhost:4000/cubejs-api/v1/load \
  -H "Authorization: $CUBE_API_TOKEN" \
  --data-urlencode 'query={"measures":["Orders.revenue"],"dimensions":["Orders.status"],"timeDimensions":[{"dimension":"Orders.created_at","granularity":"month","dateRange":"last 6 months"}]}'

The response is {"data":[{"Orders.status":"completed","Orders.created_at.month":"2026-04-01T00:00:00.000","Orders.revenue":"18420.50"}, ...]}. Measure values come back as strings.

Example 2: Make the API multi-tenant

User request:

Each customer must only ever see their own orders in the dashboard. Tokens already carry a tenant_id claim.

The agent writes queryRewrite and contextToAppId in cube.js as shown in Access Control, signs two test JWTs with different tenant_id values using CUBEJS_API_SECRET, and confirms the same query returns different rows for each. It also sets CUBEJS_DEV_MODE=false so the check is not bypassed.

Guidelines

1. Semantic layer = single source of truth — Define metrics once in Cube; all apps query the same definitions
2. Pre-aggregations for performance — Materialize common queries; Cube auto-selects the best pre-aggregation
3. Use the Playground for exploration — Build queries visually in Cube Playground before coding them into your app
4. Security context for multi-tenancy — Use queryRewrite (or access_policy) to filter queries by tenant/group; never trust filters sent by the client
5. Measures over raw SQL — Define revenue_per_user as a Cube measure, not as raw SQL in your app
6. Time dimensions for trends — Use timeDimensions with granularity for consistent time-series queries
7. Mind refresh keys — pre-aggregations refresh hourly by default; set refresh_key to match how often the source data changes, and run a separate refresh worker in production
8. Version your models — Cube models are code; store in Git, review changes, deploy via CI/CD