feat(attestation): implement Stellar-based snippet content attestation and verification (#218)

app/api/attestations/[attestationId]/route.ts

@@ -0,0 +1,33 @@
+import { NextRequest, NextResponse } from "next/server";
+import {
+  snippetAttestationService,
+  SnippetAttestationValidationError,
+} from "@/lib/snippet-attestation-service";
+
+/**
+ * GET /api/attestations/[attestationId]
+ * Retrieve a specific snippet attestation record by ID.
+ */
+export async function GET(
+  _req: NextRequest,
+  { params }: { params: Promise<{ attestationId: string }> },
+) {
+  try {
+    const { attestationId } = await params;
+    const attestation =
+      await snippetAttestationService.getAttestationById(attestationId);
+
+    return NextResponse.json({ attestation }, { status: 200 });
+  } catch (error) {
+    if (error instanceof SnippetAttestationValidationError) {
+      return NextResponse.json(
+        { error: error.message },
+        { status: error.statusCode },
+      );
+    }
+    return NextResponse.json(
+      { error: "Failed to retrieve attestation." },
+      { status: 500 },
+    );
+  }
+}

app/api/snippets/[id]/attest/route.ts

@@ -0,0 +1,60 @@
+import { NextRequest, NextResponse } from "next/server";
+import {
+  snippetAttestationService,
+  SnippetAttestationAuthError,
+  SnippetAttestationValidationError,
+} from "@/lib/snippet-attestation-service";
+
+/**
+ * POST /api/snippets/[id]/attest
+ * Create a Stellar-backed attestation for the current snippet content.
+ */
+export async function POST(
+  req: NextRequest,
+  { params }: { params: Promise<{ id: string }> },
+) {
+  try {
+    const { id } = await params;
+    let body: Record<string, any> = {};
+    try {
+      body = (await req.json()) || {};
+    } catch {
+      return NextResponse.json(
+        { error: "Request body must be valid JSON." },
+        { status: 400 },
+      );
+    }
+
+    const headerWallet = req.headers.get("x-wallet-address");
+    const attestedBy = body.attestedBy || body.walletAddress || headerWallet || "";
+
+    const attestation = await snippetAttestationService.createAttestation({
+      snippetId: id,
+      code: body.code,
+      attestedBy,
+      stellarTransactionHash: body.stellarTransactionHash || body.transactionHash,
+      network: body.network,
+      ledger: body.ledger,
+      clientProvidedHash: body.contentHash,
+    });
+
+    return NextResponse.json({ attestation }, { status: 201 });
+  } catch (error) {
+    if (error instanceof SnippetAttestationAuthError) {
+      return NextResponse.json(
+        { error: error.message },
+        { status: error.statusCode },
+      );
+    }
+    if (error instanceof SnippetAttestationValidationError) {
+      return NextResponse.json(
+        { error: error.message },
+        { status: error.statusCode },
+      );
+    }
+    return NextResponse.json(
+      { error: "Failed to create snippet attestation." },
+      { status: 500 },
+    );
+  }
+}

app/api/snippets/[id]/attestation/route.ts

@@ -0,0 +1,31 @@
+import { NextRequest, NextResponse } from "next/server";
+import {
+  snippetAttestationService,
+  SnippetAttestationValidationError,
+} from "@/lib/snippet-attestation-service";
+
+/**
+ * GET /api/snippets/[id]/attestation
+ * Retrieve the latest attestation and historical revision attestations for a snippet.
+ */
+export async function GET(
+  _req: NextRequest,
+  { params }: { params: Promise<{ id: string }> },
+) {
+  try {
+    const { id } = await params;
+    const result = await snippetAttestationService.getSnippetAttestations(id);
+    return NextResponse.json(result, { status: 200 });
+  } catch (error) {
+    if (error instanceof SnippetAttestationValidationError) {
+      return NextResponse.json(
+        { error: error.message },
+        { status: error.statusCode },
+      );
+    }
+    return NextResponse.json(
+      { error: "Failed to retrieve snippet attestations." },
+      { status: 500 },
+    );
+  }
+}