Editor Features

smelt's Language Server Protocol (LSP) implementation brings the kind of editor experience you'd expect from a statically-typed language to your data pipeline. Every feature works in real time as you type -- no build step, no waiting.

Setup first

If you haven't configured the LSP yet, see Editor Setup to get started.

Real-Time Diagnostics

Catch errors the moment you make them, not minutes later when a pipeline run fails.

smelt validates your SQL continuously: undefined model references, undeclared columns, type mismatches, and parse errors all surface as you type. In dbt, a typo in a ref() call means a failed build. In smelt, it's a red squiggle before you finish the line.

The diagnostics cover the full range of common errors:

• Undefined refs -- referencing a model that doesn't exist
• Undeclared columns -- using a column name not present in the upstream schema or source .yml
• Parse errors -- SQL syntax mistakes
• Type mismatches -- operations on incompatible types

Go-to-Definition

Trace your data lineage by jumping directly to definitions -- from a smelt.<name> call to the upstream model, from a column reference to where it's defined, or from a CTE usage to its definition.

In a large pipeline with dozens of models, you can follow the data flow without ever leaving your editor. No more grepping for model names or manually opening files.

Go-to-definition works for:

Cursor position	Jumps to
smelt.model_name	The referenced model's SQL file
smelt.sources.schema.table	The per-entity source .yml file
CTE name in FROM/JOIN	The CTE definition in the WITH clause
Table alias (e.g., t in t.column)	Where the alias is defined
Column reference	The column's definition in the upstream SELECT or source .yml

Hover Information

Hover over any model reference, source, or CTE to see its full schema -- column names, types, and where the data comes from.

Column types include nullability: a non-nullable column shows as T NOT NULL (for example INTEGER NOT NULL), while a nullable column shows the bare type (for example INTEGER). This matches the annotation syntax you write in function signatures, so what you see in hover is always consistent with what you type.

This is particularly useful when writing joins or aggregations: you can quickly check what columns are available without switching files.

Code Completion

Build queries faster with context-aware completions. smelt suggests model names inside smelt.<name>, source names inside smelt.sources.<name>, and column names when you're writing SELECT lists or WHERE clauses.

Completions are schema-aware: they know what columns each upstream model exposes, so you get accurate suggestions as you type.

Find References

Answer "who uses this model?" with a single keystroke. Find References shows every downstream consumer of a model or every usage of a CTE within a file.

In dbt, discovering downstream impact means grepping the codebase for ref('model_name'). In smelt, it's built into the editor.

Rename Refactoring

Rename a model and have every reference across the project update automatically. The LSP shows a preview of all changes before applying them, so you can review the impact.

Rename refactoring works for the following targets:

Cursor position	What is renamed
smelt.<name> model reference	All references to that model across the workspace
CTE name	The CTE definition and all usages within the same file
Column name	The column across local, upstream, and downstream files
Lambda parameter	The binder and every reference to it inside the lambda body

When renaming a lambda parameter (for example the x in fn x => x + 1), the rename updates the parameter binder and every use of that parameter within the lambda's body. Inner lambdas that shadow the parameter are left untouched. The new name must be a valid identifier, must not collide with a meta-namespace keyword (if, then, else, fn, let), and must not shadow an outer binder already referenced inside the lambda body.

Code Actions & Quick Fixes

When smelt detects an error, it often suggests a fix. The most useful code action: if you reference a model that doesn't exist yet, smelt offers to create the SQL file for you.