LikeC4 Syntax Sync

Keep packages/core/src/adapters/likec4/prompts/likec4-syntax-guide.md in sync with the canonical upstream LikeC4 DSL skill at likec4/likec4.

Our guide is injected into every model-patch prompt via {{syntaxGuide}}, so it must stay both accurate and concise (under 40 lines).

Step 1: Fetch Upstream

Fetch the relevant upstream files using gh api:

gh api repos/likec4/likec4/contents/skills/likec4-dsl/SKILL.md --jq '.content' | base64 -d
gh api repos/likec4/likec4/contents/skills/likec4-dsl/references/model.md --jq '.content' | base64 -d
gh api repos/likec4/likec4/contents/skills/likec4-dsl/references/identifier-validity.md --jq '.content' | base64 -d
gh api repos/likec4/likec4/contents/skills/likec4-dsl/references/specification.md --jq '.content' | base64 -d

Only these files contain model-patching-relevant syntax. Skip all others.

Step 2: Compare

Read the local file at packages/core/src/adapters/likec4/prompts/likec4-syntax-guide.md and compare against upstream for changes in these areas:

• Identifiers: validity rules, allowed characters, start-with constraints
• Elements: syntax forms (ID = KIND and KIND ID), nesting, property order
• Relationships: implicit/explicit source, typed (-[KIND]->, .REL_KIND), this/it
• Properties: title, summary, description, notes, technology, #tag, link, metadata
• Strings: quoting styles, escaping, triple-quote multi-line markdown
• Extend patterns: extend FQN { } for elements, extend SOURCE -> TARGET for relationships
• Anti-patterns: dots in identifiers, parent-child relationships, redefinition vs extend

Explicitly skip (not relevant to model-patching): views, deployment, CLI commands, styling/shapes/colors/icons, dynamic views, predicates, wildcards, project configuration, response discipline, eval guidance.

Step 3: Update

Apply changes to the local file following these rules:

• Keep under 40 lines total
• Preserve the existing section structure and ## LikeC4 DSL SYNTAX REFERENCE heading
• Use terse reference-card style, not explanatory prose
• Only add information that affects model-patching correctness
• Do not duplicate existing content

Step 4: Verify

npm run test

Confirm:

• Tests pass
• File starts with ## LikeC4 DSL SYNTAX REFERENCE
• File is under 40 lines