refactor: remove legacy mkOpencodeRules alias and opencode-rules compat entry

- Remove mkOpencodeRules backward-compat alias from lib/coding-rules.nix
- Remove opencode-rules alias from lib/default.nix
- Update shells/opencode.nix to use mkCodingRules / coding-rules
- Remove backward-compat test from tests/lib/coding-rules-test.nix
- Update AGENTS.md and modules/home-manager/AGENTS.md docs
- Apply nix fmt formatting to shared-options.nix

AGENTS.md

@@ -126,12 +126,11 @@ Harness-agnostic agent management. Reads canonical `agent.toml` +
 ### `lib.coding-rules`
 
 Coding rules injection. Generates `coding-rules.json` + symlinks rules from
-the AGENTS repository. The old `lib.opencode-rules` name still works.
+the AGENTS repository.
 
 | Function | Purpose |
 |----------|--------|
 | `mkCodingRules { agents, languages, concerns, frameworks, rulesDir }` | Generate rules config + shellHook. `rulesDir` defaults to `.opencode-rules` |
-| `mkOpencodeRules` | Backward-compat alias for `mkCodingRules` |
 
 ## PORT MANAGEMENT
 

CHANGELOG.md

@@ -13,6 +13,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/).
 
 ### Removed
 - Dead overlay entries for non-existent flake inputs
+- Legacy `mkOpencodeRules` alias and `lib.opencode-rules` backward-compat entry (use `mkCodingRules` / `lib.coding-rules`)
 
 ## [0.4.0] - 2026-04-15
 

lib/coding-rules.nix

@@ -112,9 +112,6 @@
       RULES_EOF
     '';
   };
-
-  # Backward-compat alias
-  mkOpencodeRules = mkCodingRules;
 in {
-  inherit mkCodingRules mkOpencodeRules;
+  inherit mkCodingRules;
 }

lib/default.nix

@@ -7,12 +7,9 @@
   # Port management utilities
   ports = import ./ports.nix {inherit lib;};
 
-  # Coding rules injection utilities (renamed from opencode-rules)
+  # Coding rules injection utilities
   coding-rules = import ./coding-rules.nix {inherit lib;};
 
-  # Backward-compat alias: opencode-rules → coding-rules
-  opencode-rules = import ./coding-rules.nix {inherit lib;};
-
   # Agent configuration management utilities
   agents = import ./agents.nix {inherit lib;};
 }

modules/home-manager/AGENTS.md

@@ -163,7 +163,7 @@ The agent system was migrated from embedded `agents.json` to file-based canonica
 | `coding.opencode.externalSkills` | `coding.agents.opencode.externalSkills` |
 | Agents embedded in `config.json` | File-based `~/.config/opencode/agents/*.md` |
 | Model hardcoded in `agents.json` | Per-machine `modelOverrides` |
-| `mkOpencodeRules` | `mkCodingRules` (old name still works) |
+| `mkOpencodeRules` | `mkCodingRules` |
 
 ### Migration steps
 

modules/home-manager/coding/agents/default.nix

@@ -1,10 +1,39 @@
 # Per-tool agent sub-modules
 # Each module handles rendering canonical agent.toml definitions
 # for a specific AI coding tool.
+#
+# Also provides the shared coding.agents.skills submodule that writes
+# ~/.agents/skills — the central skills directory used by Pi, OpenCode, etc.
 {
+  config,
+  lib,
+  pkgs,
+  ...
+}: let
+  shared = import ./shared-options.nix {inherit lib;};
+  cfg = config.coding.agents.skills;
+  mkIf = lib.mkIf;
+in {
   imports = [
     ./opencode.nix
     ./claude-code.nix
     ./pi.nix
   ];
+
+  options.coding.agents.skills = {
+    agentsInput = shared.mkAgentsInputOption ''
+      The `agents` flake input (your personal AGENTS repo).
+      When set, skills are symlinked to ~/.agents/skills.
+    '';
+
+    externalSkills = shared.externalSkillsOption;
+  };
+
+  config = mkIf (cfg.agentsInput != null) {
+    home.file.".agents/skills".source = cfg.agentsInput.lib.mkOpencodeSkills {
+      inherit pkgs;
+      customSkills = "${cfg.agentsInput}/skills";
+      externalSkills = shared.mapExternalSkills cfg.externalSkills;
+    };
+  };
 }

modules/home-manager/coding/agents/opencode.nix

@@ -17,8 +17,6 @@ in
       '';
 
       modelOverrides = shared.mkModelOverridesOption;
-
-      externalSkills = shared.externalSkillsOption;
     };
 
     config = mkIf config.coding.agents.opencode.enable {
@@ -34,18 +32,6 @@ in
           };
         };
 
-      # Skills (merged from personal AGENTS repo + optional external skills)
-      xdg.configFile."opencode/skills" = let
-        cfg = config.coding.agents.opencode;
-      in
-        mkIf (cfg.agentsInput != null) {
-          source = cfg.agentsInput.lib.mkOpencodeSkills {
-            inherit pkgs;
-            customSkills = "${cfg.agentsInput}/skills";
-            externalSkills = shared.mapExternalSkills cfg.externalSkills;
-          };
-        };
-
       # Static config dirs from AGENTS repo
       xdg.configFile."opencode/context" = let
         cfg = config.coding.agents.opencode;

modules/home-manager/coding/agents/pi.nix

@@ -15,7 +15,10 @@ in
 
       mcpServers = mkOption {
         type = types.attrsOf types.anything;
-        default = if mcpCfg != null then mcpCfg.servers else {};
+        default =
+          if mcpCfg != null
+          then mcpCfg.servers
+          else {};
         defaultText = literalExpression "config.programs.mcp.servers";
         description = ''
           MCP server configurations for Pi (pi-mcp-adapter).
@@ -41,8 +44,6 @@ in
         '';
       };
 
-      externalSkills = shared.externalSkillsOption;
-
       settings = mkOption {
         type = types.submodule {
           freeformType = types.attrsOf types.anything;
@@ -156,8 +157,11 @@ in
             then let
               filtered = filterNulls v;
             in
-              if filtered == {} then null else filtered
-            else v) attrs
+              if filtered == {}
+              then null
+              else filtered
+            else v)
+          attrs
         );
 
       piSettings = filterNulls cfg.settings;
@@ -177,8 +181,7 @@ in
       # Dynamic home.file entries for agent .md files
       agentFiles =
         if cfg.agentsInput != null
-        then
-          let
+        then let
           agentNames = builtins.attrNames cfg.agentsInput.lib.loadAgents;
         in
           builtins.listToAttrs (
@@ -213,15 +216,6 @@ in
 
         # ── Agents — pi-subagents .md files ────────────────────────────
         agentFiles
-
-        # ── Skills symlinked from AGENTS repo + external skills ────────
-        (mkIf (cfg.agentsInput != null) {
-          ".pi/agent/skills".source = cfg.agentsInput.lib.mkOpencodeSkills {
-            inherit pkgs;
-            customSkills = "${cfg.agentsInput}/skills";
-            externalSkills = shared.mapExternalSkills cfg.externalSkills;
-          };
-        })
       ];
     });
   }

modules/home-manager/coding/agents/shared-options.nix

@@ -4,7 +4,8 @@
   inherit (lib) mkOption mkEnableOption types literalExpression;
 in {
   # Common agentsInput option used by all agent modules.
-  mkAgentsInputOption = description: mkOption {
+  mkAgentsInputOption = description:
+    mkOption {
       type = types.nullOr types.anything;
       default = null;
       inherit description;
@@ -71,5 +72,6 @@ in {
       entry:
         {inherit (entry) src skillsDir;}
         // lib.optionalAttrs (entry.selectSkills != null) {inherit (entry) selectSkills;}
-    ) cfgEntries;
+    )
+    cfgEntries;
 }

shells/opencode.nix

@@ -1,5 +1,5 @@
 # OpenCode development environment with AI coding rules
-# This shell demonstrates the mkOpencodeRules library provided by this repository
+# This shell demonstrates the mkCodingRules library provided by this repository
 # Usage: nix develop .#opencode
 #
 # To enable OpenCode rules, add the agents input to your flake:
@@ -13,16 +13,16 @@
   inputs ? null,
   agents ? null,
 }: let
-  # Import the opencode-rules library
+  # Import the coding-rules library
   m3taLib = import ../lib {lib = pkgs.lib;};
 
   # Import custom packages
   customPackages = import ../pkgs {inherit pkgs inputs;};
 
   # Create rules configuration only if agents input is provided
-  # This demonstrates how to use mkOpencodeRules in a real project
+  # This demonstrates how to use mkCodingRules in a real project
   rulesConfig = lib.optionalAttrs (agents != null) {
-    rules = m3taLib.opencode-rules.mkOpencodeRules {
+    rules = m3taLib.coding-rules.mkCodingRules {
       # Pass the AGENTS repository path
       inherit agents;
 
@@ -75,7 +75,7 @@ in
     shellHook = ''
       echo "🤖 OpenCode Development Environment"
       echo ""
-      echo "This environment demonstrates the mkOpencodeRules library"
+      echo "This environment demonstrates the mkCodingRules library"
       echo "provided by the m3ta-nixpkgs repository."
       echo ""
 
@@ -121,7 +121,7 @@ in
       ${
         if (agents == null)
         then ''
-          echo "💡 Using mkOpencodeRules in your project:"
+          echo "💡 Using mkCodingRules in your project:"
           echo ""
           echo "Add to your flake.nix:"
           echo "  inputs = {"
@@ -137,7 +137,7 @@ in
           echo "      system = \"x86_64-linux\";"
           echo "      pkgs = nixpkgs.legacyPackages.''${system};"
           echo "      m3taLib = m3ta-nixpkgs.lib.''${system};"
-          echo "      rules = m3taLib.opencode-rules.mkOpencodeRules {"
+          echo "      rules = m3taLib.coding-rules.mkCodingRules {
           echo "        inherit agents;"
           echo "        languages = [\"python\" \"typescript\"];"
           echo "        frameworks = [\"n8n\"];"

tests/lib/coding-rules-test.nix

@@ -26,10 +26,7 @@ let
   in
     assert hasCorrectPrefix == true; {result = "pass";};
 
-  # Test 3: backward-compat alias exists
-  testBackwardCompat = assert codingRulesLib.mkOpencodeRules == codingRulesLib.mkCodingRules; {result = "pass";};
-
-  # Test 4: shellHook contains both the symlink command and the config generation
+  # Test 3: shellHook contains both the symlink command and the config generation
   testShellHook = let
     rules = codingRulesLib.mkCodingRules {
       agents = "/tmp/fake-agents";
@@ -43,6 +40,5 @@ let
 in {
   instructions-correct = testInstructions;
   default-rules-dir = testDefaultRulesDir;
-  backward-compat = testBackwardCompat;
   shell-hook = testShellHook;
 }