DCL Tooling

DCL tooling is local-first and compiler-backed. The same Go compiler powers command-line validation, the language server, the VS Code extension, the browser playground, and the MCP server for AI clients.

Current language: DCL v1.0. Compiler: dcl 1.0.

Command-Line Tools

BinaryPurpose
dclCompiler CLI for validation, compilation, IR, semantic summaries, diagnostics explanation, version metadata, and JSON output for AI agents.
dcl-lspLanguage server for editor diagnostics, navigation, symbols, and references.
dcl-mcpLocal stdio MCP server for AI clients such as Claude Desktop, Claude Code, VS Code MCP clients, and other MCP-compatible tools.

AI Access

DCL has two production-ready local AI access paths. MCP-native clients can launch dcl-mcp over stdio. Terminal-capable agents such as Codex, Copilot terminal workflows, Claude Code, scripts, and CI can call the dcl CLI with --json.

Use the known-good demo workspace for AI demos and smoke tests: website/src/examples/ai-demo-workspace.

dcl validate ../website/src/examples/ai-demo-workspace --json
dcl summary ../website/src/examples/ai-demo-workspace --json
dcl ir ../website/src/examples/ai-demo-workspace --json

Broad example folders may contain independent examples and are not always valid as one workspace. Point AI tools at a cohesive workspace directory or an explicit set of related .dcl files.

MCP Server

dcl-mcp exposes read-only compiler-backed tools for validating DCL workspaces, explaining diagnostics, generating IR, and summarizing the semantic model. It does not require hosting, authentication, HTTP transport, or cloud services.

Setup instructions, client configuration examples, troubleshooting, and the MCP roadmap are maintained in the repository documentation. Release archives include the binary, example MCP client configuration, and an install script where practical.

VS Code Extension

The VS Code extension bundles the compiler and language server for supported platforms. It provides syntax highlighting, compile commands, diagnostics, semantic navigation, and architecture graph views.

Playground

The browser playground is the fastest way to try DCL examples, inspect compiler diagnostics, and view the semantic model without installing local tools.