51f67f0aeb
Users can now upload any audio file to generate a CTP tempo map:
BPM detection (lib/analysis/bpm-detect.ts):
- Runs entirely client-side via Web Audio API — audio is never uploaded
- Decodes any browser-supported format (MP3, WAV, AAC, OGG, FLAC, M4A)
- Energy envelope → onset strength → autocorrelation over 55–210 BPM range
- Returns BPM, normalised confidence score, duration, and optional half-time BPM
for songs where a double-time pulse is detected
AI CTP generation (lib/analysis/ai-ctp.ts):
- Calls Claude (claude-opus-4-6) with adaptive thinking + structured JSON output
- System prompt explains CTP rules and section layout conventions
- Claude uses knowledge of well-known songs to produce accurate section maps;
falls back to a sensible generic structure for unknown tracks
- Only BPM + duration + optional metadata is sent to the server (no audio data)
API route (app/api/analyze/route.ts):
- POST /api/analyze accepts { bpm, duration, title?, artist?, mbid?, contributed_by? }
- Validates input, calls generateCTPWithAI, runs CTP schema validation
- Returns { ctp, warnings } — warnings are surfaced in the UI rather than 500-ing
UI (components/TempoAnalyzer.tsx, app/(web)/analyze/page.tsx):
- Drag-and-drop or browse file upload
- Shows BPM, confidence, duration after detection
- Half-time toggle when double-time is detected
- Metadata form: title, artist, MusicBrainz ID, contributor name
(filename parsed into artist/title as a convenience default)
- AI generation with streaming-style progress states
- Sections review via TempoMapEditor
- Download .ctp.json or submit directly to the database
Also: added @anthropic-ai/sdk to package.json, ANTHROPIC_API_KEY to .env.example,
updated next.config.mjs serverComponentsExternalPackages, added Analyze nav link.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
84 lines
2.5 KiB
TypeScript
84 lines
2.5 KiB
TypeScript
import { NextRequest, NextResponse } from "next/server";
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import { z } from "zod";
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import { generateCTPWithAI } from "@/lib/analysis/ai-ctp";
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import { validateCTP } from "@/lib/ctp/validate";
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// ─── Request schema ───────────────────────────────────────────────────────────
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const AnalyzeRequestSchema = z.object({
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bpm: z.number().min(20).max(400),
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duration: z.number().positive(),
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title: z.string().min(1).max(256).optional(),
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artist: z.string().min(1).max(256).optional(),
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mbid: z.string().uuid().optional().nullable(),
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contributed_by: z.string().min(1).max(64).optional(),
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});
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/**
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* POST /api/analyze
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*
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* Accepts BPM detection results from the browser and uses Claude to generate
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* a draft CTP document for human review.
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*
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* Body (JSON):
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* { bpm, duration, title?, artist?, mbid?, contributed_by? }
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*
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* Returns:
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* { ctp: CTPDocument, warnings: string[] }
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*/
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export async function POST(req: NextRequest) {
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let body: unknown;
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try {
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body = await req.json();
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} catch {
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return NextResponse.json({ error: "Invalid JSON body" }, { status: 400 });
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}
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const parsed = AnalyzeRequestSchema.safeParse(body);
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if (!parsed.success) {
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return NextResponse.json(
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{ error: "Invalid request", details: parsed.error.flatten() },
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{ status: 400 }
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);
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}
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const { bpm, duration, title, artist, mbid, contributed_by } = parsed.data;
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if (!process.env.ANTHROPIC_API_KEY) {
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return NextResponse.json(
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{ error: "ANTHROPIC_API_KEY is not configured on this server" },
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{ status: 503 }
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);
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}
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let ctpDoc;
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try {
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ctpDoc = await generateCTPWithAI({
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bpm,
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duration,
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title,
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artist,
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mbid: mbid ?? null,
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contributedBy: contributed_by ?? "anonymous",
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});
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} catch (err) {
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console.error("[analyze] AI generation failed:", err);
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return NextResponse.json(
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{ error: "Failed to generate CTP document", detail: String(err) },
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{ status: 500 }
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);
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}
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// Validate the AI output against the CTP schema
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const validation = validateCTP(ctpDoc);
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const warnings: string[] = [];
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if (!validation.success) {
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// Rather than 500-ing, return the draft with validation warnings so the user
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// can still see and manually correct it.
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warnings.push(...validation.errors.issues.map((i) => `${i.path.join(".")}: ${i.message}`));
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}
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return NextResponse.json({ ctp: ctpDoc, warnings });
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}
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