add gcpropose helper command

flakes/common/nix_modules/git/default.nix

@@ -22,6 +22,7 @@ with lib;
     bx = "branchdel";
     b = "branch";
     bs = "branching_setup";
+    gcp = "gcpropose";
   };
 
   environment.shellInit = lib.concatStringsSep "\n\n" [
@@ -30,5 +31,6 @@ with lib;
     (builtins.readFile ./branchd.func.sh)
     (builtins.readFile ./link_ignored.func.sh)
     (builtins.readFile ./branching_setup.func.sh)
+    (builtins.readFile ./gcpropose.func.sh)
   ];
 }

flakes/common/nix_modules/git/gcpropose.func.sh

@@ -0,0 +1,177 @@
+gcpropose() {
+  local LITELLM_BASE_URL="http://h001.net.joshuabell.xyz:8094"
+  local LITELLM_MODEL="azure-gpt-5-mini-2025-08-07"
+
+  local mode="staged"
+  while [ $# -gt 0 ]; do
+    case "$1" in
+      -a) mode="all"; shift ;;
+      -h|--help)
+        cat <<EOF
+Usage: gcpropose [-a]
+
+Propose a short git commit subject line using a LiteLLM model.
+
+Defaults:
+  - without -a: uses staged diff (git diff --staged)
+  - with -a   : uses full diff vs HEAD (git diff HEAD)
+EOF
+        return 0
+        ;;
+      *)
+        echo "Unknown arg: $1" >&2
+        return 2
+        ;;
+    esac
+  done
+
+  if ! git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
+    echo "Not inside a git repository." >&2
+    return 1
+  fi
+
+  if ! command -v curl >/dev/null 2>&1; then
+    echo "Missing dependency: curl" >&2
+    return 1
+  fi
+  if ! command -v jq >/dev/null 2>&1; then
+    echo "Missing dependency: jq" >&2
+    return 1
+  fi
+
+  local diff
+  if [ "$mode" = "all" ]; then
+    diff=$(git diff HEAD)
+  else
+    diff=$(git diff --staged)
+  fi
+
+  if [ -z "$diff" ]; then
+    if [ "$mode" = "all" ]; then
+      echo "No changes vs HEAD." >&2
+    else
+      echo "No staged changes." >&2
+    fi
+    return 1
+  fi
+
+  local git_status
+  git_status=$(git status --porcelain=v1 2>/dev/null || true)
+
+  local max_chars=10000
+  diff=$(printf "%s" "$diff" | head -c "$max_chars")
+
+  local name_status
+  if [ "$mode" = "all" ]; then
+    name_status=$(git diff --name-status HEAD 2>/dev/null || true)
+  else
+    name_status=$(git diff --name-status --staged 2>/dev/null || true)
+  fi
+
+  local prompt
+  prompt=$(cat <<EOF
+Propose a concise git commit subject line based on the changes.
+
+Rules:
+- Output ONLY the commit subject line.
+- Imperative mood.
+- Max 72 characters.
+- No quotes, no backticks, no trailing period.
+
+git status --porcelain:
+${git_status}
+
+files changed:
+${name_status}
+
+git diff (truncated):
+${diff}
+EOF
+  )
+
+  local payload_chat
+  payload_chat=$(jq -n \
+    --arg model "$LITELLM_MODEL" \
+    --arg content "$prompt" \
+    '{
+      model: $model,
+      messages: [
+        {
+          role: "system",
+          content: "You write excellent, conventional git commit subject lines."
+        },
+        {
+          role: "user",
+          content: $content
+        }
+      ],
+      temperature: 0.2
+    }')
+
+  local curl_out http_code body
+  curl_out=$(curl -sS -w "\n%{http_code}" \
+    -X POST "${LITELLM_BASE_URL}/v1/chat/completions" \
+    -H "Content-Type: application/json" \
+    ${LITELLM_API_KEY:+-H "Authorization: Bearer ${LITELLM_API_KEY}"} \
+    -d "$payload_chat") || return 1
+
+  http_code=$(printf "%s" "$curl_out" | tail -n 1)
+  body=$(printf "%s" "$curl_out" | sed '$d')
+
+  if [ "$http_code" -lt 200 ] || [ "$http_code" -ge 300 ]; then
+    echo "LiteLLM request failed (HTTP $http_code)." >&2
+    printf "%s\n" "$body" >&2
+    return 1
+  fi
+
+  local message
+  message=$(printf "%s" "$body" | jq -r '
+    .choices[0].message.content
+    | if type == "string" then .
+      elif type == "array" then (map(select(.type=="text") | .text) | join(""))
+      else ""
+      end
+  ' 2>/dev/null || true)
+  message=$(printf "%s" "$message" | sed -n '1p' | sed 's/^[[:space:]]*//;s/[[:space:]]*$//')
+
+  if [ -n "$message" ] && [ "$message" != "null" ]; then
+    printf "%s\n" "$message"
+    return 0
+  fi
+
+  local payload_responses
+  payload_responses=$(jq -n \
+    --arg model "$LITELLM_MODEL" \
+    --arg input "$prompt" \
+    '{
+      model: $model,
+      input: $input,
+      max_output_tokens: 64
+    }')
+
+  curl_out=$(curl -sS -w "\n%{http_code}" \
+    -X POST "${LITELLM_BASE_URL}/v1/responses" \
+    -H "Content-Type: application/json" \
+    ${LITELLM_API_KEY:+-H "Authorization: Bearer ${LITELLM_API_KEY}"} \
+    -d "$payload_responses") || return 1
+
+  http_code=$(printf "%s" "$curl_out" | tail -n 1)
+  body=$(printf "%s" "$curl_out" | sed '$d')
+
+  if [ "$http_code" -lt 200 ] || [ "$http_code" -ge 300 ]; then
+    echo "LiteLLM request failed (HTTP $http_code)." >&2
+    printf "%s\n" "$body" >&2
+    return 1
+  fi
+
+  message=$(printf "%s" "$body" | jq -r '(.output_text // empty)' 2>/dev/null || true)
+  message=$(printf "%s" "$message" | sed -n '1p' | sed 's/^[[:space:]]*//;s/[[:space:]]*$//')
+
+  if [ -z "$message" ] || [ "$message" = "null" ]; then
+    echo "Failed to parse model response." >&2
+    printf "%s\n" "$body" >&2
+    return 1
+  fi
+
+  printf "%s\n" "$message"
+}