function ds() {
  # Preflight checks
  (( $+commands[curl] )) || {
    echo "ds: curl must be installed." >&2
    return 1
  }
  (( $+commands[jq] )) || {
    echo "ds: jq must be installed." >&2
    return 1
  }
  [[ -n "$DEEPSEEK_API_KEY" ]] || {
    echo "ds: DEEPSEEK_API_KEY is not set." >&2
    return 1
  }
  (( $# )) || {
    echo "Usage: ds <natural language query>" >&2
    return 1
  }

  # System prompt
  local sys_prompt="You're an in-line zsh assistant running on ${OSTYPE}. \
Your task is to answer the questions without any commentation at all, \
providing only the code to run in terminal. \
You can assume that the user understands that they need to fill in placeholders like <PORT>. \
You're not allowed to explain anything and you're not a chatbot. \
You only provide shell commands or code. \
Keep the responses to one-liner answers as much as possible. \
Do not decorate the answer with tickmarks."

  # Build JSON payload safely with jq
  local payload
  payload=$(command jq -n \
    --arg system "$sys_prompt" \
    --arg user "$*" \
    '{
      model: "deepseek-v4-flash",
      messages: [
        {role: "system", content: $system},
        {role: "user",   content: $user}
      ],
      stream: false
    }') || {
    echo "ds: failed to build JSON payload." >&2
    return 1
  }

  # Call DeepSeek API
  local response
  response=$(command curl https://api.deepseek.com/chat/completions -s \
    -H "Content-Type: application/json" \
    -H "Authorization: Bearer ${DEEPSEEK_API_KEY}" \
    -d "$payload" 2>&1) || {
    echo "ds: API request failed (network error)." >&2
    return 1
  }

  # Extract result
  local result
  result=$(command jq -r '.choices[0].message.content // empty' <<< "$response" 2>/dev/null)

  if [[ -z "$result" ]]; then
    local err_msg
    err_msg=$(command jq -r '.error.message // "unknown error"' <<< "$response" 2>/dev/null)
    echo "ds: ${err_msg}" >&2
    return 1
  fi

  # Copy to system clipboard (cross-platform)
  if [[ "$OSTYPE" == darwin* ]]; then
    print -r -- "$result" | command pbcopy
  elif command -v wl-copy &>/dev/null; then
    print -r -- "$result" | command wl-copy
  elif command -v xclip &>/dev/null; then
    print -r -- "$result" | command xclip -selection clipboard
  fi

  # Echo result to terminal for visibility
  echo "$result"

  # Push into ZLE buffer so it sits on the next prompt line
  # User can edit it or press Enter to execute immediately.
  print -z "$result"
}