Developer Tool Workflows

Look up help for a nu command using the nudoccommand MCP tool. This allows the user and Claude to retreive information about a command within the conversation. It also ensures Claude and the user are operating on the same information about the command itself.

This skill is used to inspect the structure of a nu expression. It surfaces the data's described type, it's length (if applicable), and a sample of the value. The sample will contain the raw value itself for non-enumerable types, otherwise it will contain the first three values of the enumerable.

Use when writing Nushell iteration, conditionals, or error handling — for/each/reduce/any/all/take while, if/match, try/catch, the ? postfix operator. Especially relevant when choosing between for (env-propagating) and each (isolated), or when an error path needs to skip vs surface vs default. Trigger phrases: "iterate", "loop", "filter", "map", "reduce", "for loop", "try catch", "error handling", "match", "conditional".

Use when writing Nushell code that touches $env — setting or reading environment variables, persisting env across calls, scoping env to a closure, or debugging why an env mutation isn't visible somewhere. Covers do --env, with-env, the for vs each env-propagation distinction, and Nushell's automatic env vars. Trigger phrases: "env mutation", "$env", "scope", "load-env", "with-env", "do --env", "env doesn't propagate", "auto env var".

Use when organizing Nushell code into reusable units — writing a .nu file as a module, exporting commands with export def, setting up shared env via export-env, defining a module's main command, or importing/using another module with use. Trigger phrases: "nu module", "reusable nu code", "export def", "use foo.nu", "nu script organization", "module main command".

Use when writing or transforming Nushell records (key-value structures) or tables — including $env manipulation, record literals, column projection with select/reject, building records from iterables, or any time keys/values/columns are being added, removed, filtered, or restructured. Trigger phrases: "record", "table", "key/value", "select column", "build a record", "filter columns", "transform $env".

Use when manipulating strings in Nushell — parsing structured text with parse '{a} {b}', interpolating with $"...", splitting/joining/replacing, converting between strings and structured formats (json/csv/yaml/toml), or any string operation that bash would handle with sed/awk/grep. Trigger phrases: "parse string", "split", "join", "str replace", "string interpolation", "regex", "from csv", "from json string".