feat(deployment): Add support for Gemini and Codex

- RFC-MULTI-AGENT-DEPLOYMENT.md: Design for unified deployment
- modules/ai-skills.nix: Added geminiSkills option
- bin/use-skills.sh: Added GEMINI_HOME support
- bin/deploy-skill.sh: Inject configs for Codex and Gemini

RFC-MULTI-AGENT-DEPLOYMENT.md

@@ -0,0 +1,62 @@
+# RFC: Multi-Agent Skill Deployment
+
+**Status:** Draft
+**Date:** 2026-01-19
+**Author:** Gemini CLI Agent
+
+## Context
+
+This repository (`~/proj/skills`) is the single source of truth for AI capabilities. However, the runtime environment has fragmented into four distinct agents:
+
+1.  **Claude Code** (The original consumer)
+2.  **OpenCode** (The open-source alternative)
+3.  **OpenAI Codex** (The specialized coding agent)
+4.  **Gemini CLI** (The interactive shell agent)
+
+Currently, our deployment script only targets Claude and OpenCode.
+
+## The Goal: "Write Once, Deploy Everywhere"
+
+We want a single command (`./bin/deploy-skill.sh <skill>`) to make that skill available to ALL agents on the system immediately after a system rebuild.
+
+## Target Paths
+
+| Agent | Config File (Dotfiles) | Target Path (Runtime) |
+|-------|------------------------|-----------------------|
+| **Claude Code** | `home/claude.nix` | `~/.claude/skills/<name>` |
+| **OpenCode** | `home/opencode.nix` | `~/.config/opencode/skills/<name>` |
+| **OpenAI Codex** | `home/codex.nix` | `~/.codex/skills/<name>` |
+| **Gemini CLI** | `home/gemini.nix` | `~/.gemini/skills/<name>` |
+
+## Proposed Changes
+
+### 1. Update `bin/deploy-skill.sh`
+
+The script currently injects config into `claude.nix` and `opencode.nix`. We will expand it to also check for and inject into `codex.nix` and `gemini.nix` if they exist in the dotfiles repo.
+
+**Logic:**
+```bash
+# For each agent target:
+inject_home_file "$DOTFILES/home/codex.nix"  ".codex/skills/$SKILL" ...
+inject_home_file "$DOTFILES/home/gemini.nix" ".gemini/skills/$SKILL" ...
+```
+
+### 2. Standardize Skill Format
+
+Fortunately, all four agents share the same fundamental skill interface:
+*   **Definition:** `SKILL.md` (Markdown with Frontmatter)
+*   **Execution:** Bash scripts (via `run_shell_command` or similar)
+
+No changes are needed to the skill format itself, provided we stick to standard POSIX bash and relative paths in scripts.
+
+## Benefits
+
+*   **Unified Capability:** Fixing a bug in `git-commit` skill fixes it for Gemini, Claude, and Codex simultaneously.
+*   **Agent Agnosticism:** You can switch agents mid-task without losing access to your tools.
+*   **Testing:** You can verify a skill using Gemini (cheaper/faster) before using it with Claude (smarter/expensive).
+
+## Implementation Plan
+
+1.  Update `bin/deploy-skill.sh` to support the new targets.
+2.  Create placeholder `home/codex.nix` and `home/gemini.nix` in dotfiles (if missing) to test injection.
+3.  Deploy a test skill (`verify-work`) to all 4 targets.

bin/deploy-skill.sh

@@ -201,7 +201,25 @@ inject_home_file "$DOTFILES_REPO/home/opencode.nix" \
     "recursive = true;" \
     "$SKILL_NAME"
 
-# 3. Antigravity / Global Config
+# 3. Codex Config (if home/codex.nix exists)
+if [[ -f "$DOTFILES_REPO/home/codex.nix" ]]; then
+    inject_home_file "$DOTFILES_REPO/home/codex.nix" \
+        ".codex/skills/$SKILL_NAME" \
+        "../claude/skills/$SKILL_NAME" \
+        "recursive = true;" \
+        "$SKILL_NAME"
+fi
+
+# 4. Gemini Config (if home/gemini.nix exists)
+if [[ -f "$DOTFILES_REPO/home/gemini.nix" ]]; then
+    inject_home_file "$DOTFILES_REPO/home/gemini.nix" \
+        ".gemini/skills/$SKILL_NAME" \
+        "../claude/skills/$SKILL_NAME" \
+        "recursive = true;" \
+        "$SKILL_NAME"
+fi
+
+# 5. Antigravity / Global Config
 # Check if antigravity.nix exists, otherwise warn
 ANTIGRAVITY_NIX="$DOTFILES_REPO/home/antigravity.nix"
 if [[ -f "$ANTIGRAVITY_NIX" ]]; then

bin/use-skills.sh

@@ -15,6 +15,7 @@ set -euo pipefail
 
 # Default to per-repo Codex skills unless overridden by the caller.
 export CODEX_HOME="${CODEX_HOME:-$PWD/.codex}"
+export GEMINI_HOME="${GEMINI_HOME:-$PWD/.gemini}"
 
 # Ensure global auth is available in per-repo CODEX_HOME to prevent login resets
 if [[ -n "${CODEX_HOME:-}" && -f "$HOME/.codex/auth.json" ]]; then
@@ -43,6 +44,10 @@ use_skill() {
     mkdir -p "${CODEX_HOME}/skills"
     ln -sfn "$out" "${CODEX_HOME}/skills/${skill}"
   fi
+  if [[ -n "${GEMINI_HOME:-}" ]]; then
+    mkdir -p "${GEMINI_HOME}/skills"
+    ln -sfn "$out" "${GEMINI_HOME}/skills/${skill}"
+  fi
   echo "use_skill: ${skill}"
 }
 

modules/ai-skills.nix

@@ -46,6 +46,13 @@ in {
       example = [ "worklog" "hq" ];
     };
 
+    geminiSkills = mkOption {
+      type = types.listOf types.str;
+      default = [];
+      description = "Skills to deploy to Gemini CLI (~/.gemini/skills/). ${skillsList}";
+      example = [ "worklog" "web-search" ];
+    };
+
     # Lenses for orch multi-model review
     enableLenses = mkOption {
       type = types.bool;
@@ -53,12 +60,6 @@ in {
       description = "Deploy review lenses to ~/.config/lenses/";
     };
 
-    # Workflows (beads protos)
-    enableWorkflows = mkOption {
-      type = types.bool;
-      default = true;
-      description = "Deploy workflow protos to ~/.beads/molecules.jsonl";
-    };
   };
 
   config = mkIf cfg.enable {
@@ -102,6 +103,19 @@ in {
         )
       ))
 
+      # Gemini skills
+      (mkIf (cfg.geminiSkills != []) (
+        builtins.listToAttrs (
+          map (skillName: {
+            name = ".gemini/skills/${skillName}";
+            value = {
+              source = "${cfg.skillsPath}/${skillName}";
+              recursive = true;
+            };
+          }) cfg.geminiSkills
+        )
+      ))
+
       # Lenses for orch (separate subdirectories per skill)
       (mkIf cfg.enableLenses {
         ".config/lenses/code" = {
@@ -114,12 +128,6 @@ in {
         };
       })
 
-      # Workflows (beads protos)
-      (mkIf cfg.enableWorkflows {
-        ".beads/molecules.jsonl" = {
-          source = "${repoRoot}/workflows/molecules.jsonl";
-        };
-      })
     ];
   };
 }