diff --git a/github-codespaces/gemini.sh b/github-codespaces/gemini.sh
new file mode 100644
index 00000000..74bf6d3a
--- /dev/null
+++ b/github-codespaces/gemini.sh
@@ -0,0 +1,72 @@
+#!/bin/bash
+set -eo pipefail
+
+# Source common functions - try local file first, fall back to remote
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" 2>/dev/null && pwd)"
+if [[ -f "$SCRIPT_DIR/lib/common.sh" ]]; then
+    source "$SCRIPT_DIR/lib/common.sh"
+else
+    eval "$(curl -fsSL https://raw.githubusercontent.com/OpenRouterTeam/spawn/main/github-codespaces/lib/common.sh)"
+fi
+
+log_info "Gemini CLI on GitHub Codespaces"
+echo ""
+
+# 1. Ensure gh CLI and authentication
+ensure_gh_cli
+ensure_gh_auth
+
+# 2. Get repository and create codespace
+REPO="${GITHUB_REPO:-OpenRouterTeam/spawn}"
+MACHINE="${CODESPACE_MACHINE:-basicLinux32gb}"
+IDLE_TIMEOUT="${CODESPACE_IDLE_TIMEOUT:-30m}"
+
+log_info "Creating codespace for repo: $REPO"
+CODESPACE=$(create_codespace "$REPO" "$MACHINE" "$IDLE_TIMEOUT")
+
+if [[ -z "$CODESPACE" ]]; then
+    log_error "Failed to create codespace"
+    exit 1
+fi
+
+log_info "Codespace created: $CODESPACE"
+
+# Set CODESPACE_NAME for upload_file/run_server/inject_env_vars helpers
+CODESPACE_NAME="$CODESPACE"
+
+# 3. Wait for codespace to be ready
+wait_for_codespace "$CODESPACE"
+
+# 4. Install gemini
+log_warn "Installing gemini..."
+run_server "npm install -g @google/gemini-cli"
+log_info "gemini installed"
+
+# 5. Get OpenRouter API key
+echo ""
+if [[ -n "${OPENROUTER_API_KEY:-}" ]]; then
+    log_info "Using OpenRouter API key from environment"
+else
+    OPENROUTER_API_KEY=$(get_openrouter_api_key_oauth 5180)
+fi
+
+# 6. Inject environment variables via safe temp file upload
+inject_env_vars \
+    "GEMINI_API_KEY=${OPENROUTER_API_KEY}" \
+    "OPENAI_API_KEY=${OPENROUTER_API_KEY}" \
+    "OPENAI_BASE_URL=https://openrouter.ai/api/v1" \
+    "OPENROUTER_API_KEY=${OPENROUTER_API_KEY}"
+
+echo ""
+log_info "GitHub Codespace setup completed successfully!"
+log_info "Codespace: $CODESPACE"
+echo ""
+
+# 7. Start gemini interactively
+log_warn "Starting gemini..."
+log_warn "To delete codespace later, run: gh codespace delete --codespace $CODESPACE --force"
+echo ""
+sleep 1
+
+# Launch gemini
+run_server "source ~/.bashrc && gemini"
diff --git a/manifest.json b/manifest.json
index 2610f1b2..df97af8e 100644
--- a/manifest.json
+++ b/manifest.json
@@ -769,7 +769,7 @@
     "github-codespaces/goose": "implemented",
     "github-codespaces/codex": "implemented",
     "github-codespaces/interpreter": "implemented",
-    "github-codespaces/gemini": "missing",
+    "github-codespaces/gemini": "implemented",
     "github-codespaces/amazonq": "missing",
     "github-codespaces/cline": "missing",
     "e2b/claude": "implemented",