Code Tutor — API

export API="https://api.skillsafe.ai/v1/app-api"
export TOKEN="YOUR_TOKEN"      # see step 1

# every call looks like:
#   curl -s "$API/..." -H "Authorization: Bearer $TOKEN" [-d '{json}']
# jq is used below to pull fields out of the {"data": ...} envelope

import json, requests

API = "https://api.skillsafe.ai/v1/app-api"
TOKEN = "YOUR_TOKEN"  # see step 1 — read it from your shell environment in real code

def api(method, path, body=None, **headers):
    res = requests.request(method, API + path, json=body,
                           headers={"Authorization": f"Bearer {TOKEN}", **headers})
    payload = res.json()
    if not res.ok:
        raise RuntimeError(payload.get("error", {}).get("message", res.reason))
    return payload["data"]

// Node 18+ (built-in fetch)
const API = "https://api.skillsafe.ai/v1/app-api";
const TOKEN = "YOUR_TOKEN"; // see step 1 — read it from your shell environment in real code

async function api(method, path, body, extraHeaders = {}) {
  const res = await fetch(API + path, {
    method,
    headers: { Authorization: `Bearer ${TOKEN}`, "Content-Type": "application/json", ...extraHeaders },
    body: body === undefined ? undefined : JSON.stringify(body),
  });
  const json = await res.json();
  if (!res.ok) throw new Error(json.error?.message ?? res.statusText);
  return json.data;
}

package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"net/http"
	"os"
)

const API = "https://api.skillsafe.ai/v1/app-api"

var token = os.Getenv("SKILLSAFE_TOKEN") // see step 1

func call(method, path string, body, out any) error {
	var buf bytes.Buffer
	if body != nil {
		json.NewEncoder(&buf).Encode(body)
	}
	req, _ := http.NewRequest(method, API+path, &buf)
	req.Header.Set("Authorization", "Bearer "+token)
	req.Header.Set("Content-Type", "application/json")
	res, err := http.DefaultClient.Do(req)
	if err != nil {
		return err
	}
	defer res.Body.Close()
	var env struct {
		Data  json.RawMessage `json:"data"`
		Error *struct{ Message string `json:"message"` } `json:"error"`
	}
	json.NewDecoder(res.Body).Decode(&env)
	if res.StatusCode >= 400 {
		return fmt.Errorf("api %s %s: %s", method, path, env.Error.Message)
	}
	if out == nil {
		return nil
	}
	return json.Unmarshal(env.Data, out)
}

// Java 17+, no dependencies. Pair with your JSON library (Jackson, Gson…)
// to read fields out of the returned envelope.
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;

public class SkillSafe {
    static final String API = "https://api.skillsafe.ai/v1/app-api";
    static final String TOKEN = System.getenv("SKILLSAFE_TOKEN"); // see step 1
    static final HttpClient HTTP = HttpClient.newHttpClient();

    static String api(String method, String path, String jsonBody) throws Exception {
        var req = HttpRequest.newBuilder(URI.create(API + path))
            .header("Authorization", "Bearer " + TOKEN)
            .header("Content-Type", "application/json")
            .method(method, jsonBody == null
                ? HttpRequest.BodyPublishers.noBody()
                : HttpRequest.BodyPublishers.ofString(jsonBody))
            .build();
        var res = HTTP.send(req, HttpResponse.BodyHandlers.ofString());
        if (res.statusCode() >= 400) throw new RuntimeException(res.body());
        return res.body(); // envelope: {"data": …}
    }
}

require "net/http"
require "json"

API = "https://api.skillsafe.ai/v1/app-api"
TOKEN = ENV.fetch("SKILLSAFE_TOKEN") # see step 1

def api(method, path, body = nil)
  uri = URI(API + path)
  req = Net::HTTP.const_get(method.capitalize).new(uri)
  req["Authorization"] = "Bearer #{TOKEN}"
  req["Content-Type"] = "application/json"
  req.body = body.to_json if body
  res = Net::HTTP.start(uri.host, uri.port, use_ssl: true) { |h| h.request(req) }
  payload = JSON.parse(res.body)
  raise (payload.dig("error", "message") || res.message) unless res.is_a?(Net::HTTPSuccess)
  payload["data"]
end

<?php
const API = "https://api.skillsafe.ai/v1/app-api";
$TOKEN = getenv("SKILLSAFE_TOKEN"); // see step 1

function api(string $method, string $path, ?array $body = null): mixed {
    global $TOKEN;
    $ch = curl_init(API . $path);
    curl_setopt_array($ch, [
        CURLOPT_CUSTOMREQUEST  => $method,
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_HTTPHEADER     => [
            "Authorization: Bearer $TOKEN",
            "Content-Type: application/json",
        ],
        CURLOPT_POSTFIELDS     => $body === null ? null : json_encode($body),
    ]);
    $payload = json_decode(curl_exec($ch), true);
    $status  = curl_getinfo($ch, CURLINFO_RESPONSE_CODE);
    curl_close($ch);
    if ($status >= 400) {
        throw new Exception($payload["error"]["message"] ?? "HTTP $status");
    }
    return $payload["data"];
}

// .NET 8+
using System.Net.Http.Json;
using System.Text.Json;

static class SkillSafe
{
    const string Api = "https://api.skillsafe.ai/v1/app-api";
    static readonly HttpClient Http = new();

    static SkillSafe() =>
        Http.DefaultRequestHeaders.Authorization =
            new("Bearer", Environment.GetEnvironmentVariable("SKILLSAFE_TOKEN")); // see step 1

    public static async Task<JsonElement> ApiAsync(HttpMethod method, string path, object? body = null)
    {
        var req = new HttpRequestMessage(method, Api + path);
        if (body != null) req.Content = JsonContent.Create(body);
        var res = await Http.SendAsync(req);
        var json = await res.Content.ReadFromJsonAsync<JsonElement>();
        if (!res.IsSuccessStatusCode)
            throw new Exception(json.GetProperty("error").GetProperty("message").GetString());
        return json.GetProperty("data");
    }
}

curl -s -X POST "$API/guest" \
  -H "Content-Type: application/json" \
  -d '{"slug":"code-tutor"}' | jq -r '.data.token'

token = api("POST", "/guest", {"slug": "code-tutor"})["token"]

const { token } = await api("POST", "/guest", { slug: "code-tutor" });

var guest struct{ Token string `json:"token"` }
err := call("POST", "/guest", map[string]string{"slug": "code-tutor"}, &guest)

String envelope = api("POST", "/guest", """
    {"slug":"code-tutor"}""");
// token is at data.token in the returned JSON

token = api("POST", "/guest", { slug: "code-tutor" })["token"]

$token = api("POST", "/guest", ["slug" => "code-tutor"])["token"];

var guest = await SkillSafe.ApiAsync(HttpMethod.Post, "/guest",
    new { slug = "code-tutor" });
var token = guest.GetProperty("token").GetString();

curl -s "$API/me" -H "Authorization: Bearer $TOKEN" | jq '.data'

me = api("GET", "/me")
print(me["subject_type"], me["credits"])

const me = await api("GET", "/me");
console.log(me.subject_type, me.credits);

var me struct {
	SubjectType string `json:"subject_type"`
	Credits     int64  `json:"credits"`
}
err := call("GET", "/me", nil, &me)

String envelope = api("GET", "/me", null);
// data.subject_type, data.credits

me = api("GET", "/me")
puts "#{me["subject_type"]}: #{me["credits"]} credits"

$me = api("GET", "/me");
echo "{$me['subject_type']}: {$me['credits']} credits\n";

var me = await SkillSafe.ApiAsync(HttpMethod.Get, "/me");
Console.WriteLine($"{me.GetProperty("subject_type")}: {me.GetProperty("credits")} credits");

cat > config.py <<'PY'
def load_config(path):
    with open(path) as fh:
        return fh.read().strip()
PY

jq -n --rawfile c config.py \
  '{code: $c, audience: "new-dev", focus: "",
    prescan_facts: {items: [], hotspots: [], signals: {}}}' > input.json

curl -s -X POST "$API/estimate" \
  -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
  -d @input.json | jq '.data.hold_credits'

CODE = """def load_config(path):
    with open(path) as fh:
        return fh.read().strip()"""

payload = {
    "code": CODE,
    "audience": "new-dev",
    "focus": "",
    "prescan_facts": {"items": [], "hotspots": [], "signals": {}},
}

est = api("POST", "/estimate", payload)
print("worst case:", est.get("hold_credits", est.get("credits")), "credits")

const code = [
  "def load_config(path):",
  "    with open(path) as fh:",
  "        return fh.read().strip()",
].join("\n");

const payload = {
  code,
  audience: "new-dev",
  focus: "",
  prescan_facts: { items: [], hotspots: [], signals: {} },
};

const est = await api("POST", "/estimate", payload);
console.log("worst case:", est.hold_credits ?? est.credits, "credits");

const code = `def load_config(path):
    with open(path) as fh:
        return fh.read().strip()`

payload := map[string]any{
	"code":     code,
	"audience": "new-dev",
	"focus":    "",
	"prescan_facts": map[string]any{
		"items": []any{}, "hotspots": []any{}, "signals": map[string]any{},
	},
}

var est struct{ HoldCredits int64 `json:"hold_credits"` }
err := call("POST", "/estimate", payload, &est)

String code = """
    def load_config(path):
        with open(path) as fh:
            return fh.read().strip()""";

String jsonPayload = """
    {"code": %s, "audience": "new-dev",
     "focus": "",
     "prescan_facts": {"items": [], "hotspots": [], "signals": {}}}
    """.formatted(toJsonString(code));

String envelope = api("POST", "/estimate", jsonPayload);
// worst-case cost is at data.hold_credits

CODE_TEXT = <<~'PY'
  def load_config(path):
      with open(path) as fh:
          return fh.read().strip()
PY

payload = { code: CODE_TEXT, audience: "new-dev",
            focus: "",
            prescan_facts: { items: [], hotspots: [], signals: {} } }

est = api("POST", "/estimate", payload)
puts "worst case: #{est["hold_credits"] || est["credits"]} credits"

$code = <<<'PY'
def load_config(path):
    with open(path) as fh:
        return fh.read().strip()
PY;

$payload = [
    "code"          => $code,
    "audience"      => "new-dev",
    "focus"         => "",
    "prescan_facts" => ["items" => [], "hotspots" => [], "signals" => new stdClass()],
];

$est = api("POST", "/estimate", $payload);
echo "worst case: " . ($est["hold_credits"] ?? $est["credits"]) . " credits\n";

var code = """
    def load_config(path):
        with open(path) as fh:
            return fh.read().strip()
    """;

var payload = new {
    code,
    audience = "new-dev",
    focus = "",
    prescan_facts = new {
        items = Array.Empty<object>(), hotspots = Array.Empty<object>(),
        signals = new { },
    },
};

var est = await SkillSafe.ApiAsync(HttpMethod.Post, "/estimate", payload);
Console.WriteLine($"worst case: {est.GetProperty("hold_credits")} credits");

JOB_ID=$(curl -s -X POST "$API/run" \
  -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
  -H "Idempotency-Key: explain-$(date +%s)" \
  -d @input.json | jq -r '.data.job_id')

while :; do
  JOB=$(curl -s "$API/jobs/$JOB_ID" -H "Authorization: Bearer $TOKEN")
  STATUS=$(echo "$JOB" | jq -r '.data.status')
  [ "$STATUS" = "succeeded" ] || [ "$STATUS" = "failed" ] && break
  sleep 2
done

# unwrap the explanation once, then read it
echo "$JOB" | jq -r '.data.output.output' > explanation.json

jq -r '
  "\(.explanation_name) [\(.reading_level)]: \(.verdict)",
  "",
  "WALKTHROUGH",
  (.walkthrough[] | "  \(.step). \(.title) - \(.code_ref)"),
  "",
  "PITFALLS",
  (.pitfalls[] | "  (\(.severity)) \(.title)"),
  "",
  "QUIZ",
  (.quiz[] | "  Q: \(.question)\n  A: \(.answer)")' explanation.json

# and keep the ASCII flow diagram next to your notes
jq -r '.diagram' explanation.json > flow.txt

import time

job_id = api("POST", "/run", payload,
             **{"Idempotency-Key": "explain-001"})["job_id"]

while True:
    job = api("GET", f"/jobs/{job_id}")
    if job["status"] in ("succeeded", "failed"):
        break
    time.sleep(1.5)

if job["status"] == "failed":
    raise RuntimeError(job.get("error", "run failed"))

raw = job["output"]
if isinstance(raw, dict) and "output" in raw:
    raw = raw["output"]
explanation = json.loads(raw) if isinstance(raw, str) else raw

print(f'{explanation["explanation_name"]} '
      f'[{explanation["reading_level"]}]: {explanation["verdict"]}')
for step in explanation["walkthrough"]:
    print(f'  {step["step"]}. {step["title"]} ({step["code_ref"]})')
    print(f'     {step["detail"]}')
for concept in explanation["concepts"]:
    print(f'  * {concept["term"]}: {concept["explanation"]}')
for pitfall in explanation["pitfalls"]:
    print(f'  ({pitfall["severity"]}) {pitfall["title"]}')
for q in explanation["quiz"]:
    print(f'  Q: {q["question"]}\n  A: {q["answer"]}')
for c in explanation["coverage_check"]:
    print(f'  {c["id"]}: {"ok" if c["addressed"] else "SET ASIDE"} - {c["note"]}')

with open("flow.txt", "w", encoding="utf-8") as fh:
    fh.write(explanation["diagram"])

import { writeFileSync } from "node:fs";

const { job_id } = await api("POST", "/run", payload,
  { "Idempotency-Key": crypto.randomUUID() });

let job;
do {
  await new Promise((r) => setTimeout(r, 1500));
  job = await api("GET", `/jobs/${job_id}`);
} while (job.status !== "succeeded" && job.status !== "failed");

if (job.status === "failed") throw new Error(job.error ?? "run failed");

const raw = job.output?.output ?? job.output;
const explanation = typeof raw === "string" ? JSON.parse(raw) : raw;

console.log(`${explanation.explanation_name} [${explanation.reading_level}]: ${explanation.verdict}`);
for (const step of explanation.walkthrough) {
  console.log(`  ${step.step}. ${step.title} (${step.code_ref})`);
  console.log(`     ${step.detail}`);
}
for (const c of explanation.concepts) console.log(`  * ${c.term}: ${c.explanation}`);
for (const p of explanation.pitfalls) console.log(`  (${p.severity}) ${p.title}`);
for (const q of explanation.quiz) console.log(`  Q: ${q.question}\n  A: ${q.answer}`);
for (const c of explanation.coverage_check) {
  console.log(`  ${c.id}: ${c.addressed ? "ok" : "SET ASIDE"} - ${c.note}`);
}

writeFileSync("flow.txt", explanation.diagram);

var started struct{ JobID string `json:"job_id"` }
if err := call("POST", "/run", payload, &started); err != nil {
	log.Fatal(err)
}

var job struct {
	Status string          `json:"status"`
	Error  string          `json:"error"`
	Output json.RawMessage `json:"output"`
}
for {
	if err := call("GET", "/jobs/"+started.JobID, nil, &job); err != nil {
		log.Fatal(err)
	}
	if job.Status == "succeeded" || job.Status == "failed" {
		break
	}
	time.Sleep(1500 * time.Millisecond)
}

// job.Output is {"output": "<json string>"} — unwrap, unquote, then unmarshal:
type Explanation struct {
	Name         string `json:"explanation_name"`
	ReadingLevel string `json:"reading_level"`
	Verdict      string `json:"verdict"`
	Overview     string `json:"overview"`
	Walkthrough  []struct {
		Step    int    `json:"step"`
		Title   string `json:"title"`
		Detail  string `json:"detail"`
		CodeRef string `json:"code_ref"`
	} `json:"walkthrough"`
	Diagram  string `json:"diagram"`
	Concepts []struct {
		Term, Explanation string
	} `json:"concepts"`
	Pitfalls []struct {
		Severity, Title, Detail string
		CodeRef                 string `json:"code_ref"`
	} `json:"pitfalls"`
	Quiz []struct {
		Question, Answer string
	} `json:"quiz"`
	NextSteps []string `json:"next_steps"`
	Summary   string   `json:"summary"`
}
var wrapper struct{ Output string `json:"output"` }
json.Unmarshal(job.Output, &wrapper)
var explanation Explanation
json.Unmarshal([]byte(wrapper.Output), &explanation)

fmt.Printf("%s [%s]: %s\n", explanation.Name, explanation.ReadingLevel, explanation.Verdict)
for _, s := range explanation.Walkthrough {
	fmt.Printf("  %d. %s (%s)\n", s.Step, s.Title, s.CodeRef)
}
for _, p := range explanation.Pitfalls {
	fmt.Printf("  (%s) %s\n", p.Severity, p.Title)
}
for _, q := range explanation.Quiz {
	fmt.Printf("  Q: %s\n  A: %s\n", q.Question, q.Answer)
}
os.WriteFile("flow.txt", []byte(explanation.Diagram), 0o644)

String envelope = api("POST", "/run", jsonPayload);
String jobId = /* data.job_id via your JSON library */;

while (true) {
    String job = api("GET", "/jobs/" + jobId, null);
    String status = /* data.status */;
    if (status.equals("succeeded") || status.equals("failed")) break;
    Thread.sleep(1500);
}
// The explanation is at data.output.output as a JSON string — parse it again, then read
// explanation_name, reading_level, verdict, overview, walkthrough[] (step/title/detail/code_ref),
// diagram, concepts[] (term/explanation), pitfalls[] (severity/title/code_ref/detail),
// coverage_check[] (id/addressed/note), quiz[] (question/answer), next_steps[] and summary.
// Finally keep the ASCII diagram next to your notes:
//   Files.writeString(Path.of("flow.txt"), diagram);

started = api("POST", "/run", payload)

job = nil
loop do
  job = api("GET", "/jobs/#{started["job_id"]}")
  break if %w[succeeded failed].include?(job["status"])
  sleep 1.5
end
raise (job["error"] || "run failed") if job["status"] == "failed"

raw = job["output"].is_a?(Hash) ? job["output"].fetch("output", job["output"]) : job["output"]
explanation = raw.is_a?(String) ? JSON.parse(raw) : raw

puts "#{explanation["explanation_name"]} [#{explanation["reading_level"]}]: #{explanation["verdict"]}"
explanation["walkthrough"].each do |s|
  puts "  #{s["step"]}. #{s["title"]} (#{s["code_ref"]})"
  puts "     #{s["detail"]}"
end
explanation["concepts"].each { |c| puts "  * #{c["term"]}: #{c["explanation"]}" }
explanation["pitfalls"].each { |p| puts "  (#{p["severity"]}) #{p["title"]}" }
explanation["quiz"].each { |q| puts "  Q: #{q["question"]}\n  A: #{q["answer"]}" }
explanation["coverage_check"].each { |c| puts "  #{c["id"]}: #{c["addressed"] ? "ok" : "SET ASIDE"}" }

File.write("flow.txt", explanation["diagram"])

$started = api("POST", "/run", $payload);

do {
    sleep(2);
    $job = api("GET", "/jobs/" . $started["job_id"]);
} while (!in_array($job["status"], ["succeeded", "failed"]));

if ($job["status"] === "failed") {
    throw new Exception($job["error"] ?? "run failed");
}

$raw = is_array($job["output"]) ? ($job["output"]["output"] ?? $job["output"]) : $job["output"];
$explanation = is_string($raw) ? json_decode($raw, true) : $raw;

echo "{$explanation['explanation_name']} [{$explanation['reading_level']}]: {$explanation['verdict']}\n";
foreach ($explanation["walkthrough"] as $s) {
    echo "  {$s['step']}. {$s['title']} ({$s['code_ref']})\n";
    echo "     {$s['detail']}\n";
}
foreach ($explanation["concepts"] as $c) {
    echo "  * {$c['term']}: {$c['explanation']}\n";
}
foreach ($explanation["pitfalls"] as $p) {
    echo "  ({$p['severity']}) {$p['title']}\n";
}
foreach ($explanation["quiz"] as $q) {
    echo "  Q: {$q['question']}\n  A: {$q['answer']}\n";
}
foreach ($explanation["coverage_check"] as $c) {
    echo "  {$c['id']}: " . ($c["addressed"] ? "ok" : "SET ASIDE") . "\n";
}

file_put_contents("flow.txt", $explanation["diagram"]);

var started = await SkillSafe.ApiAsync(HttpMethod.Post, "/run", payload);
var jobId = started.GetProperty("job_id").GetString();

JsonElement job;
while (true)
{
    job = await SkillSafe.ApiAsync(HttpMethod.Get, $"/jobs/{jobId}");
    var status = job.GetProperty("status").GetString();
    if (status is "succeeded" or "failed") break;
    await Task.Delay(1500);
}

var rawText = job.GetProperty("output").GetProperty("output").GetString();
using var doc = JsonDocument.Parse(rawText!);
var explanation = doc.RootElement;

Console.WriteLine($"{explanation.GetProperty("explanation_name")} " +
                  $"[{explanation.GetProperty("reading_level")}]: {explanation.GetProperty("verdict")}");
foreach (var s in explanation.GetProperty("walkthrough").EnumerateArray())
{
    Console.WriteLine($"  {s.GetProperty("step")}. {s.GetProperty("title")} " +
                      $"({s.GetProperty("code_ref")})");
}
foreach (var p in explanation.GetProperty("pitfalls").EnumerateArray())
{
    Console.WriteLine($"  ({p.GetProperty("severity")}) {p.GetProperty("title")}");
}
foreach (var q in explanation.GetProperty("quiz").EnumerateArray())
{
    Console.WriteLine($"  Q: {q.GetProperty("question")}");
    Console.WriteLine($"  A: {q.GetProperty("answer")}");
}

await File.WriteAllTextAsync("flow.txt",
                             explanation.GetProperty("diagram").GetString()!);

# -N disables buffering so events print as they arrive
curl -N -s -X POST "$API/run-stream" \
  -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
  -H "Idempotency-Key: explain-$(date +%s)" \
  -d @input.json

# event: job
# data: {"job_id":"job_...","status":"running"}
#
# event: delta
# data: {"text":"{\"explanation_name\":\"config.py"}
# ...
# event: done
# data: {"job_id":"job_...","status":"succeeded","charged_credits":418,"output":{"output":"{...}"}}

import json, requests

result = None
with requests.post(
    API + "/run-stream",
    headers={"Authorization": f"Bearer {TOKEN}",
             "Idempotency-Key": "explain-001"},
    json=payload,
    stream=True,
) as r:
    r.raise_for_status()
    event = None
    for line in r.iter_lines(decode_unicode=True):
        if not line:
            continue
        if line.startswith("event:"):
            event = line[len("event:"):].strip()
        elif line.startswith("data:"):
            data = json.loads(line[len("data:"):].strip())
            if event == "delta":
                print(".", end="", flush=True)          # live progress
            elif event == "done":
                result = data
            elif event == "error":
                raise RuntimeError(data.get("message", "run failed"))

explanation = json.loads(result["output"]["output"])    # authoritative
print("charged:", result["charged_credits"], "-", explanation["explanation_name"])
for step in explanation["walkthrough"]:
    print(f'  {step["step"]}. {step["title"]}')
open("flow.txt", "w", encoding="utf-8").write(explanation["diagram"])

const res = await fetch(API + "/run-stream", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${TOKEN}`,
    "Content-Type": "application/json",
    "Idempotency-Key": crypto.randomUUID(),
  },
  body: JSON.stringify(payload),
});

const reader = res.body.getReader();
const decoder = new TextDecoder();
let buf = "", done = null;

for (;;) {
  const chunk = await reader.read();
  if (chunk.done) break;
  buf += decoder.decode(chunk.value, { stream: true });
  const frames = buf.split("\n\n");
  buf = frames.pop();
  for (const frame of frames) {
    const name = /^event:\s*(.+)$/m.exec(frame)?.[1];
    const body = /^data:\s*(.+)$/m.exec(frame)?.[1];
    if (!name || !body) continue;
    const data = JSON.parse(body);
    if (name === "delta") process.stdout.write(".");   // live progress
    if (name === "done") done = data;
    if (name === "error") throw new Error(data.message ?? "run failed");
  }
}

const explanation = JSON.parse(done.output.output);
console.log(`\n${done.charged_credits} credits - ${explanation.explanation_name}`);
for (const step of explanation.walkthrough) console.log(`  ${step.step}. ${step.title}`);
writeFileSync("flow.txt", explanation.diagram);

body, _ := json.Marshal(payload)
req, _ := http.NewRequest("POST", API+"/run-stream", bytes.NewReader(body))
req.Header.Set("Authorization", "Bearer "+token)
req.Header.Set("Content-Type", "application/json")
req.Header.Set("Idempotency-Key", "explain-001")

res, err := http.DefaultClient.Do(req)
if err != nil {
	log.Fatal(err)
}
defer res.Body.Close()

var event string
var final map[string]any
sc := bufio.NewScanner(res.Body)
sc.Buffer(make([]byte, 0, 64*1024), 4*1024*1024)
for sc.Scan() {
	line := sc.Text()
	switch {
	case strings.HasPrefix(line, "event:"):
		event = strings.TrimSpace(strings.TrimPrefix(line, "event:"))
	case strings.HasPrefix(line, "data:"):
		var data map[string]any
		json.Unmarshal([]byte(strings.TrimPrefix(line, "data:")), &data)
		switch event {
		case "delta":
			fmt.Print(".") // live progress
		case "done":
			final = data
		case "error":
			log.Fatal(data["message"])
		}
	}
}
// final["output"].(map[string]any)["output"].(string) is the explanation JSON —
// unmarshal it into the Explanation struct from step 4, then write explanation.Diagram to disk.

// Java 17+ — read the stream line by line instead of buffering the body.
var req = HttpRequest.newBuilder(URI.create(API + "/run-stream"))
    .header("Authorization", "Bearer " + TOKEN)
    .header("Content-Type", "application/json")
    .header("Idempotency-Key", "explain-001")
    .POST(HttpRequest.BodyPublishers.ofString(jsonPayload))
    .build();

var res = HTTP.send(req, HttpResponse.BodyHandlers.ofLines());
String event = null, done = null;
for (String line : (Iterable<String>) res.body()::iterator) {
    if (line.startsWith("event:")) {
        event = line.substring(6).trim();
    } else if (line.startsWith("data:")) {
        String data = line.substring(5).trim();
        if ("delta".equals(event)) System.out.print(".");   // live progress
        else if ("done".equals(event)) done = data;
        else if ("error".equals(event)) throw new RuntimeException(data);
    }
}
// parse `done`, then parse data.output.output again — it is a JSON string holding
// explanation_name, reading_level, walkthrough[], diagram, concepts[], pitfalls[], quiz[] and the rest.

require "net/http"
require "json"

uri = URI(API + "/run-stream")
req = Net::HTTP::Post.new(uri)
req["Authorization"] = "Bearer #{TOKEN}"
req["Content-Type"] = "application/json"
req["Idempotency-Key"] = "explain-001"
req.body = payload.to_json

event = nil
done = nil
Net::HTTP.start(uri.host, uri.port, use_ssl: true) do |http|
  http.request(req) do |res|
    res.read_body do |chunk|
      chunk.each_line do |line|
        line = line.strip
        if line.start_with?("event:")
          event = line.delete_prefix("event:").strip
        elsif line.start_with?("data:")
          data = JSON.parse(line.delete_prefix("data:").strip)
          case event
          when "delta" then print "."           # live progress
          when "done"  then done = data
          when "error" then raise (data["message"] || "run failed")
          end
        end
      end
    end
  end
end

explanation = JSON.parse(done["output"]["output"])
puts "\n#{done["charged_credits"]} credits - #{explanation["explanation_name"]}"
explanation["walkthrough"].each { |s| puts "  #{s["step"]}. #{s["title"]}" }
File.write("flow.txt", explanation["diagram"])

$event = null;
$done  = null;

$ch = curl_init(API . "/run-stream");
curl_setopt_array($ch, [
    CURLOPT_POST       => true,
    CURLOPT_HTTPHEADER => [
        "Authorization: Bearer $TOKEN",
        "Content-Type: application/json",
        "Idempotency-Key: explain-001",
    ],
    CURLOPT_POSTFIELDS => json_encode($payload),
    CURLOPT_WRITEFUNCTION => function ($ch, $chunk) use (&$event, &$done) {
        foreach (explode("\n", $chunk) as $line) {
            $line = trim($line);
            if (str_starts_with($line, "event:")) {
                $event = trim(substr($line, 6));
            } elseif (str_starts_with($line, "data:")) {
                $data = json_decode(trim(substr($line, 5)), true);
                if ($event === "delta") { echo "."; }        // live progress
                elseif ($event === "done") { $done = $data; }
                elseif ($event === "error") { throw new Exception($data["message"] ?? "run failed"); }
            }
        }
        return strlen($chunk);
    },
]);
curl_exec($ch);
curl_close($ch);

$explanation = json_decode($done["output"]["output"], true);
echo "\n{$done['charged_credits']} credits - {$explanation['explanation_name']}\n";
foreach ($explanation["walkthrough"] as $s) { echo "  {$s['step']}. {$s['title']}\n"; }
file_put_contents("flow.txt", $explanation["diagram"]);

var req = new HttpRequestMessage(HttpMethod.Post, Api + "/run-stream") {
    Content = JsonContent.Create(payload),
};
req.Headers.Add("Idempotency-Key", "explain-001");

using var res = await Http.SendAsync(req, HttpCompletionOption.ResponseHeadersRead);
using var reader = new StreamReader(await res.Content.ReadAsStreamAsync());

string? evt = null, done = null;
while (await reader.ReadLineAsync() is { } line)
{
    if (line.StartsWith("event:")) evt = line[6..].Trim();
    else if (line.StartsWith("data:"))
    {
        var data = line[5..].Trim();
        if (evt == "delta") Console.Write(".");            // live progress
        else if (evt == "done") done = data;
        else if (evt == "error") throw new Exception(data);
    }
}

using var final = JsonDocument.Parse(done!);
var text = final.RootElement.GetProperty("output").GetProperty("output").GetString();
using var explanationDoc = JsonDocument.Parse(text!);
var explanation = explanationDoc.RootElement;
Console.WriteLine(explanation.GetProperty("explanation_name"));
foreach (var s in explanation.GetProperty("walkthrough").EnumerateArray())
    Console.WriteLine($"  {s.GetProperty("step")}. {s.GetProperty("title")}");
await File.WriteAllTextAsync("flow.txt",
                             explanation.GetProperty("diagram").GetString()!);