Support multiple Claude Code installations via parameterized plugins

lib/resolve.nix

@@ -48,7 +48,8 @@ let
 
   # --- Plugin resolution ---
 
-  resolvePlugin =
+  # Import plugin source by path or name string
+  importPlugin =
     ref:
     if builtins.isPath ref then
       import ref
@@ -57,6 +58,24 @@ let
     else
       import (pluginsDir + "/${ref}");
 
+  # Call a plugin function with args, or return plain attrset as-is
+  callPlugin = imported: args: if builtins.isFunction imported then imported args else imported;
+
+  # Resolve a plugin reference:
+  #   "claude-code"                                     → import + call with {}
+  #   { plugin = "claude-code"; configDir = "~/.x"; }   → import + call with { configDir = "~/.x"; }
+  #   /path/to/plugin.nix                               → import + call with {}
+  resolvePlugin =
+    ref:
+    if builtins.isAttrs ref then
+      let
+        imported = importPlugin (ref.plugin or (throw "plugin attr requires a 'plugin' key"));
+        args = builtins.removeAttrs ref [ "plugin" ];
+      in
+      callPlugin imported args
+    else
+      callPlugin (importPlugin ref) { };
+
   pluginConfigs = map resolvePlugin (config.plugins or [ ]);
 
   # Strip meta fields before merging

plugins/claude-code/README.md

@@ -5,15 +5,25 @@ Runs [Claude Code](https://docs.anthropic.com/en/docs/claude-code) inside the VM
 ## Usage
 
 ```nix
+# Default — uses ~/.claude on the host
 { plugins = [ "claude-code" ]; }
+
+# Custom config directory — use a separate Claude installation
+{ plugins = [ { plugin = "claude-code"; configDir = "~/.claude-work"; } ]; }
 ```
 
+## Parameters
+
+| Name | Default | Description |
+|---|---|---|
+| `configDir` | `~/.claude` | Host-side directory to mount as `~/.claude` inside the VM |
+
 ## What it provides
 
 | Category | Details |
 |---|---|
 | **Packages** | `claude-code` |
-| **Mounts** | `~/.claude` — preserves config, credentials, and session history across VM restarts |
+| **Mounts** | `<configDir>` → `~/.claude` — preserves config, credentials, and session history across VM restarts |
 | **Domains** | `anthropic.com`, `claude.com`, `sentry.io` |
 | **Setup** | Overlays tmpfs on `~/.claude/{debug,statsig,telemetry,todos}` to work around virtiofs lacking `O_TMPFILE` support |
 

plugins/claude-code/default.nix

@@ -1,9 +1,10 @@
+{ configDir ? "~/.claude" }:
 {
   nix.packages = [ "claude-code" ];
 
   mounts = [
     {
-      source = "~/.claude";
+      source = configDir;
       target = "~/.claude";
     }
   ];

tests/run-nix-tests.sh

@@ -82,6 +82,16 @@ assert_eq "user domain" "$(jq_get "$json" '.network.domains | index("user.exampl
 # Hook from plugin
 assert_eq "plugin hook" "$(jq_get "$json" '.hooks."post-up"[0]')" "echo plugin-loaded"
 
+# ---------------------------------------------------------------------------
+echo "==> Test: parameterized plugin (function with args)"
+json=$(resolve "$FIXTURES/with_plugin_args.nix")
+
+assert_eq "projectName" "$(jq_get "$json" '.projectName')" "test-plugin-args"
+assert_eq "plugin env passed through" "$(jq_get "$json" '.env.GREETING')" "world"
+assert_eq "plugin packages" "$(jq_get "$json" '.nix.packages | index("curl") != null')" "true"
+assert_eq "plugin domain" "$(jq_get "$json" '.network.domains | index("fn.example.com") != null')" "true"
+assert_eq "user domain" "$(jq_get "$json" '.network.domains | index("user.example.com") != null')" "true"
+
 # ---------------------------------------------------------------------------
 echo "==> Test: empty mounts get default"
 json=$(resolve "$FIXTURES/empty_mounts.nix")