Documentation

Start with the getting-started page: it starts a node, creates a user, runs a first query over HTTP and opens the console.

Reference

• Scalar functions
• Aggregate functions
• Aggregate combinators
• Window functions
• Table functions
• Data types
• Settings
• Configuration variables
• Error codes
• Metrics
• Formats
• Storage format

FAQ

Does my ClickHouse SQL work?

Much of it does. muscles accepts a subset of ClickHouse SQL, so check a function in the function reference, and see compatibility below for where it ends.

How do I connect Grafana, Python or a ClickHouse driver?

Point them at the ClickHouse HTTP interface. The features page lists the tools we connect to.

Can I query my data without moving it?

Yes. Declare an external table over Iceberg, PostgreSQL or another system, and query and join it like a local table.

Do I lose data if a server crashes?

Not once a write is acknowledged: muscles acknowledges it after it is on disk. Architecture shows how a row is stored.

Where do I set a limit or an option?

A query or session changes settings with SET. The server takes environment variables or YAML keys.

What does this error mean?

Look up the code from the error body in error codes.

How do I monitor it?

The server exports Prometheus metrics.

Can I leave later?

Yes. The storage format is public, and conversion tools to Iceberg and ClickHouse are in progress.

How do I get access?

muscles is in private beta, and runs on your own servers.

Interfaces

POST /api/query returns columnar JSON, /api/query/stream streams a result, and /api/query.arrow returns an Arrow IPC stream. POST / is the ClickHouse HTTP interface, which ClickHouse drivers, Grafana and JDBC tools use. The getting-started page shows both.

The function reference lists 340 scalar functions and the aggregate reference 55 aggregates, including quantile, uniq and time bucketing. The window function reference lists the 13 window functions and says which aggregates run as windows.

Compatibility with ClickHouse

muscles accepts a subset of ClickHouse SQL and returns results in several ClickHouse formats, so ClickHouse HTTP drivers can connect. The compatibility ends there: the HTTP interface and the SQL dialect. muscles is a separate product and is not affiliated with ClickHouse, Inc.