Cellar

Use cellar to look up the API of JVM dependencies instead of guessing or hallucinating signatures.

Project-aware commands (run from project root)

Query the current project's code and all its dependencies. Cellar auto-detects the build tool (Mill, sbt, scala-cli).

cellar get [--module <name>] <fqn>       # single symbol (signature, members, docs)
cellar list [--module <name>] <package>  # list symbols in a package or class
cellar search [--module <name>] <query>  # case-insensitive substring search

• Mill/sbt projects: --module is required (e.g. --module lib, --module core)
• scala-cli projects: omit --module
• --no-cache: skip classpath cache, re-extract from build tool
• --java-home <path>: override JRE classpath
• -l, --limit <N>: max results for list/search (default: 50)

External commands (query arbitrary Maven coordinates)

Query any published artifact by explicit coordinate (group:artifact:version):

cellar get-external <coordinate> <fqn>       # single symbol
cellar list-external <coordinate> <package>  # list symbols
cellar search-external <coordinate> <query>  # search by name
cellar get-source <coordinate> <fqn>         # fetch source code
cellar deps <coordinate>                     # dependency tree

• Coordinates must be explicit: group:artifact_3:version (no :: shorthand)
• Use latest as the version to resolve the most recent release
• -r, --repository <url>: extra Maven repository (repeatable)

Workflow

1. Don't know the package? → cellar search / cellar search-external
2. Know the package, not the type? → cellar list / cellar list-external
3. Know the type? → cellar get / cellar get-external
4. Need the implementation? → cellar get-source

Examples

# Look up a Scala 3 trait
cellar get-external org.typelevel:cats-core_3:2.10.0 cats.Monad

# Look up a Java class
cellar get-external org.apache.commons:commons-lang3:3.14.0 org.apache.commons.lang3.StringUtils

# List a package
cellar list-external io.circe:circe-core_3:0.14.6 io.circe

# Search for a method
cellar search-external org.typelevel:cats-core_3:2.10.0 flatMap

# Get source code
cellar get-source org.typelevel:cats-core_3:2.10.0 cats.Monad

# Dependency tree
cellar deps org.typelevel:cats-effect_3:3.5.4

# Project-aware (from a Mill project root)
cellar get --module lib cats.Monad
cellar list --module core cats
cellar search --module lib flatMap

Output

• stdout: Markdown — ready to consume directly
• stderr: diagnostics (warnings, truncation notices)
• Exit 0: success, Exit 1: error