a coding harness in 18 lines of bash with but make it pretty

agent.sh

#!/bin/bash
j(){ jq -n --arg i "$I" --argjson t "$(<tools.json)" --arg s "$(<prompt.txt)" --arg p "${P}" \
  '{model:"auto",input:$i,tools:$t,instructions:$s}+(if $p=="" then{}else{previous_response_id:$p}end)';}
while I=${I:-$(gum input)}; do
  gum style --foreground 99 "→ ${O:-$I}"
  R=$(gum spin --show-output -- curl -s "$OPENAI_BASE_URL/responses" -H "Content-Type: application/json" -d "$(j)")
  P=$(jq -r .id <<<"$R"); unset I O
  while read -r X; do
    case $(jq -r .type <<<"$X") in
    message) jq -r .content[0].text <<<"$X" | gum format;;
    function_call)
      C=$(jq -r '.arguments|fromjson|.command' <<<"$X")
      gum style --faint "\$ $C"
      export D=$(jq -r .call_id <<<"$X") O=$(eval "$C" 2>&1)
      I=$(jq -n '[{type:"function_call_output",call_id:$ENV.D,output:$ENV.O}]');;
    esac
  done < <(jq -c .output[] <<<"$R")
done