ComfyUI AI gen lesson changes

.env.example

@@ -21,8 +21,10 @@ SMTP_FROM="DrawIt <no-reply@example.com>"
 COMFYUI_URL=http://127.0.0.1:8188
 COMFYUI_API_KEY=
 # Path to a ComfyUI workflow exported in API format ("Save (API format)").
-COMFYUI_WORKFLOW=./comfyui/coloring-book.workflow_api.json
+COMFYUI_WORKFLOW=./comfyui/ColorBook01.json
-# Node ids in that workflow to inject into: the positive prompt text, and the sampler seed.
+# Node ids in that workflow: the positive-prompt node and the sampler (seed) node.
 COMFYUI_PROMPT_NODE=6
 COMFYUI_SEED_NODE=3
+# Placeholder inside the positive prompt that gets replaced with the creator's subject.
+COMFYUI_SUBJECT_TOKEN=[DrawItSubject]
 COMFYUI_TIMEOUT_MS=120000

comfyui/README.md

@@ -10,11 +10,17 @@ server and turns the result into a lesson. Nothing leaves your machine.
 3. Provide a workflow exported in **API format** (ComfyUI → Settings → enable dev mode →
    "Save (API format)") and point `COMFYUI_WORKFLOW` at it.
 
-`coloring-book.workflow_api.json` here is the **stock SD1.5 text-to-image workflow** as a starting
+`ColorBook01.json` here is the active workflow (`COMFYUI_WORKFLOW`). Its positive-prompt node contains a
-point. DrawIt injects its prompt into the positive-prompt node and a random seed into the sampler node:
+**`[DrawItSubject]` placeholder** — DrawIt replaces that token with the creator's one-word subject and
+sets a fresh random seed; the rest of your prompt is kept exactly as written. (`coloring-book.workflow_api.json`
+is the older stock SD1.5 template, kept for reference.)
 
-- `COMFYUI_PROMPT_NODE` (default `6`) — the positive `CLIPTextEncode` node.
+- `COMFYUI_PROMPT_NODE` (default `6`) — the positive `CLIPTextEncode` node containing `[DrawItSubject]`.
 - `COMFYUI_SEED_NODE` (default `3`) — the `KSampler` node.
+- `COMFYUI_SUBJECT_TOKEN` (default `[DrawItSubject]`) — the placeholder to substitute.
+
+Example: node 6 text `"coloring book page, single cute [DrawItSubject], black and white line art, …"`
+with subject `Zebra` becomes `"coloring book page, single cute Zebra, black and white line art, …"`.
 
 ## Tips for clean line art (matters — we vectorize it with potrace)
 

src/app/api/create/route.ts

@@ -1,6 +1,6 @@
 import { NextResponse } from "next/server";
 import { requireCreator } from "@/lib/session";
-import { isCreateEnabled, buildPrompt } from "@/lib/comfyui";
+import { isCreateEnabled, resolvePrompt } from "@/lib/comfyui";
 import { moderateSubject } from "@/lib/moderation";
 import { createCreatedLesson, processCreation, listCreatedForUser } from "@/lib/createdLessons";
 
@@ -31,7 +31,7 @@ export async function POST(req: Request) {
     return NextResponse.json({ error: "Let's pick a different, friendly thing to draw!" }, { status: 422 });
   }
 
-  const prompt = buildPrompt(mod.subject);
+  const prompt = resolvePrompt(mod.subject);
   const status = mod.decision === "allowlist" ? "pending" : "needs_review";
   const row = createCreatedLesson({ userId: user.id, level, subject: mod.subject, prompt, moderation: mod.decision, status });
 

src/lib/comfyui.ts

@@ -11,18 +11,30 @@ import path from "node:path";
 
 const URL_BASE = (process.env.COMFYUI_URL || "").replace(/\/$/, "");
 const API_KEY = process.env.COMFYUI_API_KEY || "";
-const WORKFLOW_PATH = process.env.COMFYUI_WORKFLOW || "./comfyui/coloring-book.workflow_api.json";
+const WORKFLOW_PATH = process.env.COMFYUI_WORKFLOW || "./comfyui/ColorBook01.json";
 const TIMEOUT_MS = Number(process.env.COMFYUI_TIMEOUT_MS || 120000);
-const PROMPT_NODE = process.env.COMFYUI_PROMPT_NODE || "6"; // positive CLIPTextEncode in the default workflow
+const PROMPT_NODE = process.env.COMFYUI_PROMPT_NODE || "6"; // positive CLIPTextEncode in the workflow
-const SEED_NODE = process.env.COMFYUI_SEED_NODE || "3"; // KSampler in the default workflow
+const SEED_NODE = process.env.COMFYUI_SEED_NODE || "3"; // KSampler in the workflow
+// Placeholder inside the workflow's positive prompt that we replace with the creator's subject.
+const SUBJECT_TOKEN = process.env.COMFYUI_SUBJECT_TOKEN || "[DrawItSubject]";
 
 export function isCreateEnabled(): boolean {
   return URL_BASE.length > 0;
 }
 
-/** The fixed coloring-book prompt with the subject interpolated. */
+/**
-export function buildPrompt(subject: string): string {
+ * The resolved positive prompt that will be sent: the workflow's prompt-node text with the
-  return `A coloring book page of a ${subject}, clean black-and-white line art, bold crisp outlines, simple composition, large open areas to color, white background, no shading, no grayscale, no color, no gradients, no heavy background detail, printable page.`;
+ * `[DrawItSubject]` placeholder replaced by the subject. Stored for audit. Falls back to the bare
+ * subject if the workflow can't be read.
+ */
+export function resolvePrompt(subject: string): string {
+  try {
+    const text = loadWorkflow()[PROMPT_NODE]?.inputs?.text;
+    if (typeof text === "string") return text.split(SUBJECT_TOKEN).join(subject);
+  } catch {
+    /* fall through */
+  }
+  return subject;
 }
 
 function authHeaders(): Record<string, string> {
@@ -40,15 +52,20 @@ async function sleep(ms: number) {
 }
 
 /**
- * Generate coloring-book line art for the given prompt. Returns the PNG bytes.
+ * Generate coloring-book line art for the given subject. Returns the PNG bytes.
+ * Injects the subject into the workflow's prompt placeholder + a fresh seed.
  * Throws on timeout / ComfyUI errors (caller marks the lesson 'failed').
  */
-export async function generateLineArt(prompt: string): Promise<Buffer> {
+export async function generateLineArt(subject: string): Promise<Buffer> {
   if (!isCreateEnabled()) throw new Error("Create is disabled (COMFYUI_URL not set).");
 
   const workflow = loadWorkflow();
-  // Inject our prompt + a fresh seed into the configured nodes.
+  // Replace the [DrawItSubject] placeholder in the positive prompt with the creator's subject.
-  if (workflow[PROMPT_NODE]?.inputs) workflow[PROMPT_NODE].inputs.text = prompt;
+  const promptNode = workflow[PROMPT_NODE];
+  if (promptNode?.inputs && typeof promptNode.inputs.text === "string") {
+    promptNode.inputs.text = promptNode.inputs.text.split(SUBJECT_TOKEN).join(subject);
+  }
+  // Fresh seed each run so repeats vary.
   if (workflow[SEED_NODE]?.inputs) workflow[SEED_NODE].inputs.seed = Math.floor(Math.random() * 1e15);
 
   const clientId = `drawit-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;

src/lib/createdLessons.ts

@@ -119,7 +119,7 @@ export async function processCreation(id: number): Promise<void> {
     updateCreatedStatus(id, "generating");
     const { generateLineArt } = await import("./comfyui");
     const { pngToTemplateSvg } = await import("./vectorize");
-    const png = await generateLineArt(row.prompt);
+    const png = await generateLineArt(row.subject);
     const templateSvg = await pngToTemplateSvg(png);
     setReady(id, templateSvg, `data:image/png;base64,${png.toString("base64")}`);
   } catch (e) {