From dafb4c0d47ab0e938363d56950dce7c3b0e6d502 Mon Sep 17 00:00:00 2001
From: Tom Baldwin <tom@polymorphism.co.uk>
Date: Thu, 2 Jul 2026 18:34:37 +0100
Subject: [PATCH] Add Candor Language Server template
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candor (https://candor.poly.io) renders a per-function side-effect map in the
editor — CodeLens (effects + blast radius), architecture-policy diagnostics, and
effect-provenance hover — from a precomputed report covering JVM/TS/Rust/Swift
code. The server ships in the candor-ts npm package as `candor-lsp`; the
installer follows the typescript-language-server pattern.
---
 .../templates/lsp/candor-lsp/README.md        | 25 +++++++
 .../templates/lsp/candor-lsp/installer.json   | 36 ++++++++++
 .../templates/lsp/candor-lsp/template.json    | 67 +++++++++++++++++++
 3 files changed, 128 insertions(+)
 create mode 100644 src/main/resources/templates/lsp/candor-lsp/README.md
 create mode 100644 src/main/resources/templates/lsp/candor-lsp/installer.json
 create mode 100644 src/main/resources/templates/lsp/candor-lsp/template.json

diff --git a/src/main/resources/templates/lsp/candor-lsp/README.md b/src/main/resources/templates/lsp/candor-lsp/README.md
new file mode 100644
index 000000000..dc2ac5a40
--- /dev/null
+++ b/src/main/resources/templates/lsp/candor-lsp/README.md
@@ -0,0 +1,25 @@
+You can use the [candor language server](https://candor.poly.io) to see each function's **side-effect
+map** where the code is:
+
+ * **CodeLens** on every effectful function: `⚡ Db, Net · blast radius 12` — the effects it (transitively)
+   performs and how many functions are affected if it changes;
+ * **Diagnostics**: the repo's architecture policy (e.g. "the domain layer does no I/O") checked live —
+   a violation is a squiggle at the offending function;
+ * **Hover**: effect provenance — the call chain through which an inherited effect reaches its source.
+
+The server renders a **candor report** — it does not analyse source itself. Produce one with any candor
+engine (JVM bytecode / TypeScript / Rust / Swift; see [candor.poly.io](https://candor.poly.io)), e.g.:
+
+**jbang candor@tombaldwin/candor-java target/classes --json .candor/report.json**   (JVM)
+
+**npx -y candor-ts src --out .candor/report**   (TypeScript/JavaScript)
+
+Setup:
+* [Install Node.js](https://nodejs.org/en/download)
+* Open a terminal and execute:
+
+**npm install -g candor-ts**
+
+It will install the `candor-lsp` executable (the language server ships in the candor-ts package). The
+server resolves the report at `<project>/.candor/report` and the policy from the checked-in
+`.candor/config` — no per-project server configuration is needed.
diff --git a/src/main/resources/templates/lsp/candor-lsp/installer.json b/src/main/resources/templates/lsp/candor-lsp/installer.json
new file mode 100644
index 000000000..558aea12d
--- /dev/null
+++ b/src/main/resources/templates/lsp/candor-lsp/installer.json
@@ -0,0 +1,36 @@
+{
+  "id": "candor-lsp",
+  "name": "Candor Language Server",
+  "executeOnStartServer": false,
+  "properties": {
+    "workingDir" : "$USER_HOME$/.lsp4ij/lsp/candor-lsp/node_modules"
+  },
+  "check": {
+    "exec": {
+      "name": "Trying current command",
+      "command": "${server.command}",
+      "timeout": 2000
+    }
+  },
+  "run": {
+    "exec": {
+      "name": "Install Candor Language Server",
+      "workingDir": "${workingDir}",
+      "ignoreStderr": true,
+      "command": {
+        "windows": "npm.cmd install candor-ts --force",
+        "default": "npm install candor-ts --force"
+      },
+      "onSuccess": {
+        "configureServer": {
+          "name": "Configure Candor Language Server command",
+          "command": {
+            "windows": "${workingDir}/.bin/candor-lsp.cmd",
+            "default": "${workingDir}/.bin/candor-lsp"
+          },
+          "update": true
+        }
+      }
+    }
+  }
+}
diff --git a/src/main/resources/templates/lsp/candor-lsp/template.json b/src/main/resources/templates/lsp/candor-lsp/template.json
new file mode 100644
index 000000000..1e191bdf5
--- /dev/null
+++ b/src/main/resources/templates/lsp/candor-lsp/template.json
@@ -0,0 +1,67 @@
+{
+  "id": "candor-lsp",
+  "name": "Candor Language Server",
+  "programArgs": {
+    "windows": "cmd /C candor-lsp.cmd",
+    "default": "candor-lsp"
+  },
+  "fileTypeMappings": [
+    {
+      "fileType": {
+        "name": "JAVA",
+        "patterns": [
+          "*.java"
+        ]
+      },
+      "languageId": "java"
+    },
+    {
+      "fileType": {
+        "name": "Kotlin",
+        "patterns": [
+          "*.kt",
+          "*.kts"
+        ]
+      },
+      "languageId": "kotlin"
+    },
+    {
+      "fileType": {
+        "name": "TypeScript",
+        "patterns": [
+          "*.ts",
+          "*.tsx"
+        ]
+      },
+      "languageId": "typescript"
+    },
+    {
+      "fileType": {
+        "name": "JavaScript",
+        "patterns": [
+          "*.js",
+          "*.jsx",
+          "*.mjs"
+        ]
+      },
+      "languageId": "javascript"
+    },
+    {
+      "fileType": {
+        "name": "Rust",
+        "patterns": [
+          "*.rs"
+        ]
+      },
+      "languageId": "rust"
+    },
+    {
+      "fileType": {
+        "patterns": [
+          "*.swift"
+        ]
+      },
+      "languageId": "swift"
+    }
+  ]
+}