feat: add Claude Code marketplace and dexter-lsp plugin

[pquadri]

Summary

Turns the dexter repo into a Claude Code marketplace, so users can install Dexter as their Elixir LSP in Claude Code with just two commands:

claude plugin marketplace add remoteoss/dexter
claude plugin install dexter-lsp@dexter

Changes

• .claude-plugin/marketplace.json — makes this repo a Claude Code marketplace named dexter
• plugins/dexter-lsp/.claude-plugin/plugin.json — plugin manifest that wires up dexter lsp for .ex, .exs, and .heex files, with followDelegates and debug exposed as user-configurable options
• README.md — adds a Claude Code section to the editor setup docs

How it works

Claude Code's LSP tool supports a plugin system. The lspServers entry in plugin.json tells Claude Code to spawn dexter lsp when opening Elixir files, giving it go-to-definition, hover docs, find references, workspace symbols, and more.

Test plan

• claude plugin marketplace add remoteoss/dexter succeeds
• claude plugin install dexter-lsp@dexter succeeds
• Open an Elixir project — LSP tool resolves hover and go-to-definition on .ex files
• userConfig prompts appear for followDelegates and debug on install

---

Note

Low Risk
Low risk: adds Claude Code marketplace/plugin manifests and documentation only, with no changes to core LSP/runtime behavior.

Overview
Makes this repo a Claude Code plugin marketplace by adding .claude-plugin/marketplace.json and a dexter-lsp plugin manifest that launches dexter lsp for .ex, .exs, and .heex files.

Updates README.md with Claude Code setup instructions (enabling the LSP tool and installing via claude plugin marketplace add / claude plugin install) and exposes followDelegates/debug as Claude user-configurable options via the plugin manifest.

^{Reviewed by Cursor Bugbot for commit 305f540. Bugbot is set up for automated code reviews on this repo. Configure here.}

[JesseHerrick]

Thanks for the PR @pquadri! I think this is a great addition. Going to sleep on whether to keep this in the same repo or in a different one. If you have any docs on the matter, I'd also be glad to read them. Should be able to merge this tomorrow.

[JesseHerrick]

I'd say that this would be the version of the plugin itself, no? So v0.1

[cursor]

Cursor Bugbot has reviewed your changes and found 2 potential issues.

^{Reviewed by Cursor Bugbot for commit 305f540. Configure here.}

[cursor]

Boolean config values passed as strings, silently ignored

High Severity

The initializationOptions values "${user_config.follow_delegates}" and "${user_config.debug}" are wrapped in JSON string quotes, so Claude Code's template interpolation produces string values like "true" or "false" rather than JSON booleans. The Dexter LSP server in server.go uses Go type assertions (opts["followDelegates"].(bool)) that silently fail for string values, causing both settings to always fall back to their hardcoded defaults (followDelegates=true, debug=false). User configuration is effectively non-functional.

 

^{Reviewed by Cursor Bugbot for commit 305f540. Configure here.}

[cursor]

Plugin uses unsupported default field in userConfig

Medium Severity

The userConfig entries use a default field ("default": true and "default": false), but Claude Code's plugin system does not currently support the default property in userConfig — it only supports type, title, description, required, and sensitive. The defaults won't be seeded into settings.json on install, so the ${user_config.*} references in initializationOptions will resolve to empty/unresolved values rather than the intended defaults.

 

^{Reviewed by Cursor Bugbot for commit 305f540. Configure here.}