diff --git a/src/components/modals/add-node-form.tsx b/src/components/modals/add-node-form.tsx
index 36ae6ee..08d045e 100644
--- a/src/components/modals/add-node-form.tsx
+++ b/src/components/modals/add-node-form.tsx
@@ -386,7 +386,12 @@ export function AddNodeForm() {
           return
         }
         setStatus("error")
-        setErrorMsg("Something went wrong. Please try again.")
+        if (err instanceof Response) {
+          const body = await err.json().catch(() => null) as { errorCode?: string; message?: string } | null
+          setErrorMsg(body?.message || body?.errorCode || `Node creation failed (HTTP ${err.status})`)
+        } else {
+          setErrorMsg("Something went wrong. Please try again.")
+        }
       }
     },
     [selectedSchema, fields, visibleFields, fieldValues, selectedFile, setBudget, close]
diff --git a/src/lib/__tests__/add-node-form.test.tsx b/src/lib/__tests__/add-node-form.test.tsx
new file mode 100644
index 0000000..550a34f
--- /dev/null
+++ b/src/lib/__tests__/add-node-form.test.tsx
@@ -0,0 +1,193 @@
+/**
+ * Tests for AddNodeForm error-surfacing behaviour.
+ * Verifies that when createNode() throws a non-402 Response, the actual
+ * Jarvis error body is extracted and shown — not the generic fallback.
+ */
+import { describe, it, expect, vi, beforeEach } from "vitest"
+import { render, screen, waitFor } from "@testing-library/react"
+import userEvent from "@testing-library/user-event"
+import React from "react"
+
+// ---------------------------------------------------------------------------
+// Hoisted mocks — must be set up before any imports that reference the modules
+// ---------------------------------------------------------------------------
+
+const { mockCheckNodeExists, mockCreateNode, mockGetPrice, mockGetSchemaDomains } = vi.hoisted(
+  () => ({
+    mockCheckNodeExists: vi.fn().mockResolvedValue({ exists: false }),
+    mockCreateNode: vi.fn().mockResolvedValue({ status: "ok" }),
+    mockGetPrice: vi.fn().mockResolvedValue(0),
+    mockGetSchemaDomains: vi.fn().mockResolvedValue({ hidden_types: [], hidden_domains: [] }),
+  })
+)
+
+vi.mock("@/lib/graph-api", () => ({
+  checkNodeExists: (...args: unknown[]) => mockCheckNodeExists(...args),
+  createNode: (...args: unknown[]) => mockCreateNode(...args),
+  getSchemaDomains: (...args: unknown[]) => mockGetSchemaDomains(...args),
+  addImageContent: vi.fn(),
+  ALLOWED_IMAGE_TYPES: ["image/jpeg", "image/png", "image/webp", "image/gif"],
+  MAX_IMAGE_UPLOAD_BYTES: 10 * 1024 * 1024,
+}))
+
+vi.mock("@/lib/sphinx", () => ({
+  getPrice: (...args: unknown[]) => mockGetPrice(...args),
+  payL402: vi.fn().mockResolvedValue(undefined),
+}))
+
+// ---------------------------------------------------------------------------
+// Modal store — preselectedNodeType = "Lingo" to skip type selection
+// ---------------------------------------------------------------------------
+const mockClose = vi.fn()
+let mockPreselectedNodeType: string | null = "Lingo"
+
+vi.mock("@/stores/modal-store", () => ({
+  useModalStore: (sel?: (s: unknown) => unknown) => {
+    const state = {
+      activeModal: "add",
+      close: mockClose,
+      preselectedNodeType: mockPreselectedNodeType,
+    }
+    return sel ? sel(state) : state
+  },
+}))
+
+// ---------------------------------------------------------------------------
+// User store
+// ---------------------------------------------------------------------------
+const mockSetBudget = vi.fn()
+
+vi.mock("@/stores/user-store", () => ({
+  useUserStore: (sel?: (s: unknown) => unknown) => {
+    const state = {
+      pubKey: "testpubkey",
+      routeHint: "",
+      isAdmin: false,
+      budget: 500,
+      setBudget: mockSetBudget,
+    }
+    return sel ? sel(state) : state
+  },
+}))
+
+// ---------------------------------------------------------------------------
+// Schema store — Lingo schema with name (required) and lingo_type (optional)
+// ---------------------------------------------------------------------------
+const LINGO_SCHEMA = {
+  ref_id: "lingo-ref",
+  type: "Lingo",
+  parent: "Thing",
+  node_key: "lingo-name",
+  color: "#64748b",
+  attributes: [
+    { key: "name", type: "string", required: true },
+    { key: "definition", type: "string", required: false },
+    { key: "lingo_type", type: "string", required: false },
+  ],
+  inherited_attributes: [],
+}
+
+vi.mock("@/stores/schema-store", () => ({
+  useSchemaStore: (sel?: (s: unknown) => unknown) => {
+    const state = { schemas: [LINGO_SCHEMA], edges: [] }
+    return sel ? sel(state) : state
+  },
+}))
+
+// ---------------------------------------------------------------------------
+// Import component after mocks
+// ---------------------------------------------------------------------------
+import { AddNodeForm } from "@/components/modals/add-node-form"
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+/** Fill the name field and click submit */
+async function fillAndSubmit(name = "test lingo") {
+  const nameInput = await screen.findByPlaceholderText("Required")
+  await userEvent.clear(nameInput)
+  await userEvent.type(nameInput, name)
+  const submitBtn = screen.getByRole("button", { name: /add lingo/i })
+  await userEvent.click(submitBtn)
+}
+
+// ---------------------------------------------------------------------------
+// Setup
+// ---------------------------------------------------------------------------
+beforeEach(() => {
+  vi.clearAllMocks()
+  mockPreselectedNodeType = "Lingo"
+  mockCheckNodeExists.mockResolvedValue({ exists: false })
+  mockCreateNode.mockResolvedValue({ status: "ok" })
+  mockGetPrice.mockResolvedValue(0)
+})
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+describe("AddNodeForm — error body surfacing", () => {
+  it("a. displays the Jarvis 400 message body instead of generic fallback", async () => {
+    const errorResponse = new Response(
+      JSON.stringify({ message: "Unknown attribute 'lingo_type' for schema 'Lingo'." }),
+      { status: 400, headers: { "Content-Type": "application/json" } }
+    )
+    mockCreateNode.mockRejectedValue(errorResponse)
+
+    render(<AddNodeForm />)
+    await fillAndSubmit()
+
+    await waitFor(() => {
+      expect(
+        screen.getByText("Unknown attribute 'lingo_type' for schema 'Lingo'.")
+      ).toBeInTheDocument()
+    })
+    expect(screen.queryByText(/Something went wrong/)).not.toBeInTheDocument()
+  })
+
+  it("b. displays errorCode when message is absent", async () => {
+    const errorResponse = new Response(
+      JSON.stringify({ errorCode: "ERROR_SCHEMA_ATTRIBUTE_UNKNOWN" }),
+      { status: 400, headers: { "Content-Type": "application/json" } }
+    )
+    mockCreateNode.mockRejectedValue(errorResponse)
+
+    render(<AddNodeForm />)
+    await fillAndSubmit()
+
+    await waitFor(() => {
+      expect(screen.getByText("ERROR_SCHEMA_ATTRIBUTE_UNKNOWN")).toBeInTheDocument()
+    })
+    expect(screen.queryByText(/Something went wrong/)).not.toBeInTheDocument()
+  })
+
+  it("c. displays HTTP status fallback when body is unparseable", async () => {
+    const errorResponse = new Response("not json", {
+      status: 400,
+      headers: { "Content-Type": "text/plain" },
+    })
+    mockCreateNode.mockRejectedValue(errorResponse)
+
+    render(<AddNodeForm />)
+    await fillAndSubmit()
+
+    await waitFor(() => {
+      expect(screen.getByText("Node creation failed (HTTP 400)")).toBeInTheDocument()
+    })
+    expect(screen.queryByText(/Something went wrong/)).not.toBeInTheDocument()
+  })
+
+  it("d. displays generic fallback for non-Response throws", async () => {
+    mockCreateNode.mockRejectedValue(new Error("network failure"))
+
+    render(<AddNodeForm />)
+    await fillAndSubmit()
+
+    await waitFor(() => {
+      expect(
+        screen.getByText("Something went wrong. Please try again.")
+      ).toBeInTheDocument()
+    })
+  })
+})