PSL AST Layers Guide
Teaches the agent to navigate Prisma schema (PSL) syntax trees using the correct typed, red, and green layers
- Repository
- prisma/orm
- Stars
- 47,663
- Licence
- Apache-2.0
- Files
- 1 file
What it does
When working on Prisma Schema Language code, this skill tells the agent which layer of the parser's syntax tree to use: typed AST classes by default, red-tree navigation helpers to move around the tree, and never the low-level green storage. It also steers the agent away from anti-patterns such as converting the tree back to text to extract facts, reading green nodes directly, and materializing lazy iterators into arrays.
Great for
- Developers building PSL interpreters, formatters, or language server features inside the Prisma repository
- Contributors writing helpers in the psl-parser package who need consistent tree-access patterns
- Maintainers reviewing PSL code for lossless, typed access
Skip it if
- People who do not work on Prisma schema parsing: the guidance is specific to the internal @internal/psl-parser API and will not apply to other codebases
- Projects that use a different parser or syntax tree library, since the class and helper names would not exist there
Try asking
- “Write a helper that finds the model enclosing the field at the cursor in the language server”
- “Refactor this formatter code so it stops stringifying attributes and checks the tree instead”
- “Add a getter to the FieldDeclarationAst class instead of iterating children at the call site”
- “Find the previous non-trivia declaration before this model in the PSL document”
Install in 3 steps
- 1
Download the skill
The ZIP contains the 1 original files, the Apache-2.0 licence and an attribution note.
psl-ast-layers.zip - 2
Add it to your agent
Claude Code (all projects)
mkdir -p ~/.claude/skills && unzip psl-ast-layers.zip -d ~/.claude/skills/Claude Code / Agent SDK (this project only)
mkdir -p .claude/skills && unzip psl-ast-layers.zip -d .claude/skills/Claude apps (web/desktop): Settings → Capabilities → Skills → Upload skill, and choose the ZIP.
- 3
Ask for the task
No special command needed — the agent reads the skill's description and loads it when your request matches. Try one of the prompts above.
Get better results
- Name the consumer you are writing (interpreter, language server, formatter) so the agent picks the right layer and helpers.
- Ask the agent to explain why it chose a typed getter over a navigation helper, to check it followed the layer rules.
- Review any generated walk loops: the skill expects a cast as the first step in each loop body.
What's inside
- SKILL.md
Redistributed unmodified from prisma/orm under the Apache-2.0 licence. The assessment was drafted with AI from the skill's files on 2026-10-29. Skills can instruct your agent to run code — read SKILL.md and any scripts before installing.