Saiku Analytics

Open-source Semantic Layer analytics for cubes — drag-and-drop in the browser, SQL through Mondrian + Calcite, and a typed REST surface so AI agents can query without ever seeing MDX.

saiku.bi · Live demo · Issues · Discussions

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Try it in 30 seconds

docker run -d -p 8080:8080 --name saiku ghcr.io/spiculedata/saiku

Then open http://localhost:8080/ui/ and log in with admin / admin. The container ships with a self-contained H2 + FoodMart demo cube — drag fields onto rows, columns, or filters and the SPA writes MDX for you.

A hosted instance is always live at https://demo.saiku.bi (auto-reset nightly).

What is Saiku

Saiku started in 2010 as an open-source OLAP browser for Mondrian. In 2026 it was rebuilt as a modern Semantic Layer on top of:

• Mondrian 4.8.1.x (Spicule fork) — with a Calcite-based SQL planner alongside the legacy SqlQuery builder. Calcite is the default; force legacy with -Dmondrian.backend=legacy.
• Apache Arrow wire format for cellsets, so the browser and any programmatic consumer share a zero-copy result envelope.
• Jetty 12 EE10 + Jersey 3.1 + Spring 6 + Spring Security 6.5 in a single-JAR Picocli launcher.
• SvelteKit 5 + Vite for the SPA (separate repo, served from inside the same JAR at /ui/).

AI Query API + MCP

Saiku 4.x exposes a typed REST surface — /rest/saiku/api/ai/* — designed for LLM agents. Hierarchies, levels, measures and synonyms are discoverable via /ai/cubes and /ai/schema, and a single POST /ai/query translates a JSON description of a question into validated MDX, runs it, and returns typed {value, formatted, unit} cells. Every validation failure carries a {status, field, available} envelope so an agent can self-correct without scraping logs.

The container also bundles saiku-mcp, a stdio Model Context Protocol wrapper so Claude Desktop / Cursor / Cline can wire to a running Saiku with one line of config:

{
  "command": "docker",
  "args":    ["exec", "-i", "saiku", "saiku-mcp"]
}

See docs/AI-QUERY-API.md and docs/schema-annotations.md for the typed contract and the saiku.semantic.* annotation namespace cubes use to describe themselves to agents.

Observability

Saiku ships opt-in OpenTelemetry instrumentation via the OTel Java agent — zero code changes, zero overhead when off. Setting OTEL_EXPORTER_OTLP_ENDPOINT activates auto-instrumentation for Jetty, Jersey, JDBC (every Mondrian-emitted SQL becomes a child span), outbound HTTP, JVM metrics, and DBCP2 connection pool metrics. Trace context is injected into the Saiku log pattern automatically.

docker run -d -p 8080:8080 \
  -e OTEL_EXPORTER_OTLP_ENDPOINT=http://otel-collector:4318 \
  -e OTEL_SERVICE_NAME=saiku-prod \
  ghcr.io/spiculedata/saiku:latest

Without the endpoint env var the agent is never loaded. See docs/observability.md for the full env-var reference, sampling guidance, and what's not yet covered (Tier 2 custom spans for ThinQueryService etc.).

Build from source

JDK 21 + Maven 3.9+ required.

# Compile, unit tests, Spotless format check (CI gate):
mvn verify

# Build the runnable fat-JAR:
mvn -pl saiku-launcher -am -Dmaven.test.skip=true package

# Run:
java -jar saiku-launcher/target/saiku-*.jar serve --port 8080 --home ./saiku-home

Whole-API integration tests (boots Jetty + the launcher's WAR in-process against the seeded FoodMart H2 datasource):

mvn verify -P integration

See CLAUDE.md for the full layout, the dependency catalog (saiku-bom), and the GitHub Packages auth gotcha for local builds.

Repository layout

saiku-bom/             # central dependency-version catalogue
saiku-core/
  saiku-olap-util/     # olap4j helpers
  saiku-service/       # Semantic Layer service, AI Query, schema gen, async, cache
  saiku-semantic/      # YAML semantic layer
  saiku-web/           # JAX-RS REST resources
saiku-webapp/          # Servlet webapp (Spring XML wiring)
saiku-launcher/        # Picocli CLI + embedded Jetty serving the WAR
saiku-mcp/             # stdio JSON-RPC MCP wrapper
saiku-ui/              # SvelteKit SPA (independent versioning)

The SvelteKit SPA lives in saiku-ui/ and is built independently; the launcher serves the static dist/ under /ui/.

Getting help

• Bugs and feature requests: open an issue.
• Questions, ideas, walkthroughs: GitHub Discussions.
• Stack Overflow tag: saiku.
• Commercial support, hosted, training: hello@saiku.bi.

The old groups.google.com/a/saiku.meteorite.bi lists and ##saiku IRC channel are no longer monitored.

Contributing

See CONTRIBUTING.md. Short version:

• feature/<name> branch off development — see the Gitflow note in CLAUDE.md.
• Run mvn spotless:apply before committing (a pre-commit hook is available via ./scripts/install-hooks.sh).
• Tests live in **/src/test/java/; integration tests in saiku-launcher/src/test/java/org/saiku/launcher/it/.
• Open the PR against development, not main. main is the release branch — only release/* and hotfix/* PRs go there.

License

Saiku is dual-licensed under Apache 2.0 and EPL 1.0. See LICENSE.txt. A summary lives at https://saiku.bi/#license.

History

The original Saiku project was started by Tom Barber and Paul Stoellberger in 2010 at Meteorite BI and now lives at Spicule. Contributors are listed on the GitHub contributors page.

For release notes see Releases.

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