Simple Chat API call script

chat.sh

#!/usr/bin/env bash

_MODEL="gpt-4o"
_ENDPOINT=""
_ENDPOINT_OPENAI="https://api.openai.com/v1/chat/completions"
_ENDPOINT_DEEPSEEK="https://api.deepseek.com/v1/chat/completions"
_ENDPOINT_GEMINI="https://generativelanguage.googleapis.com/v1beta/openai/chat/completions"
_ENDPOINT_OLLAMA="http://localhost:11434/v1/chat/completions"
_KEY_NAME=""
_KEY_NAME_OPENAI="OPENAI_API_KEY"
_KEY_NAME_DEEPSEEK="DEEPSEEK_API_KEY"
_KEY_NAME_GEMINI="GEMINI_API_KEY"

HELP="Usage: ask.sh [-m MODEL] [-e ENDPOINT] [-k KEY_NAME] [-d] [MESSAGE...]"

conf=${XDG_CONFIG_HOME:-$HOME/.config}/chat/config
verbose=0

function encode {
  local str="$*"
  str=${str//\\/\\\\}
  str=${str//\"/\\\"}
  str=${str//$'\t'/\\t}
  str=${str//$'\n'/\\n}
  str=${str//$'\r'/}
  echo "$str"
}

function extract {
  local key="$1"
  shift
  local json="$*"
  # shellcheck disable=SC2059
  printf "$(echo "$json"|sed -n 's/.*"'"$key"'":[[:space:]]*"\([^"\\]*\(\\.[^"\\]*\)*\)".*/\1/p')"
}

if [ -f "$conf" ]; then
  # shellcheck disable=SC1090
  source "$conf"
fi

while getopts m:e:k:vh opt; do
  case $opt in
    m)
      MODEL=$OPTARG
      ;;
    e)
      ENDPOINT=$OPTARG
      ;;
    k)
      KEY_NAME=$OPTARG
      ;;
    v)
      verbose=1
      ;;
    h)
      echo "$HELP"
      exit 0
      ;;
    \?)
      echo "Invalid option: $OPTARG" 1>&2
      echo ""
      echo "$HELP" 1>&2
      exit 1
      ;;
  esac
done
shift $((OPTIND - 1))

MODEL="${MODEL:-$_MODEL}"
ENDPOINT="${ENDPOINT:-$_ENDPOINT}"
KEY_NAME="${KEY_NAME:-$_KEY_NAME}"

if [[ "$MODEL" =~ ^gpt* ]] || [[ "$MODEL" =~ ^chatgpt* ]] || [[ "$MODEL" =~ ^o1-* ]]; then
  ENDPOINT="${ENDPOINT:-$_ENDPOINT_OPENAI}"
  KEY_NAME="${KEY_NAME:-$_KEY_NAME_OPENAI}"
elif [[ "$MODEL" =~ ^deepseek* ]]; then
  ENDPOINT="${ENDPOINT:-$_ENDPOINT_DEEPSEEK}"
  KEY_NAME="${KEY_NAME:-$_KEY_NAME_DEEPSEEK}"
elif [[ "$MODEL" =~ ^gemini* ]]; then
  ENDPOINT="${ENDPOINT:-$_ENDPOINT_GEMINI}"
  KEY_NAME="${KEY_NAME:-$_KEY_NAME_GEMINI}"
else
  ENDPOINT="${ENDPOINT:-$_ENDPOINT_OLLAMA}"
fi

if [ -z "$ENDPOINT" ]; then
  echo "ENDPOINT is needed to be set for $MODEL model."
  exit 1
fi

key=""
if [ -z "$KEY_NAME" ]; then
  if [ "$ENDPOINT" = "$_ENDPOINT_OPENAI" ] || [ "$ENDPOINT" = "$_ENDPOINT_DEEPSEEK" ] || [ "$ENDPOINT" = "$_ENDPOINT_GEMINI" ]; then
    echo "KEY_NAME is needed to be set for $MODEL model."
    exit 1
  fi
else
  key="${!KEY_NAME}"
  if [ -z "$key" ]; then
    echo "$KEY_NAME is not set. Please set $KEY_NAME environment variable."
    exit 1
  fi
fi

if [ -p /dev/stdin ] || [ -f /dev/stdin ]; then
  content=$(cat /dev/stdin)
  content="${content}

$*"
else
  content="$*"
fi
content=$(encode "$content")

input_json='{"model": "'$MODEL'", "messages": [{"role": "user", "content": "'"$content"'"}]}'
if [ "$verbose" = 1 ]; then
  echo "Request:"
  echo "$input_json"
  echo ""
fi

json=$(curl -s "$ENDPOINT" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $key" \
  -d "$input_json")

if [ "$verbose" = 1 ]; then
  echo "Response:"
  echo "$json"
  echo ""
fi

output=$(extract content "$json")
if [ -z "$output" ];then
  echo "Failed to get a response from the API (ENDPOINT=$ENDPOINT, MODEL=$MODEL)." 1>&2
  echo "" 1>&2
  extract message "$json" >&2
  exit 1
fi
echo "$output"