stakwork · gonzaloaune · Aug 27, 2026 · Aug 27, 2026
diff --git a/src/app/layout.tsx b/src/app/layout.tsx
@@ -1,8 +1,24 @@
 import type { Metadata, Viewport } from "next"
 import { Rajdhani, Plus_Jakarta_Sans, Fira_Code } from "next/font/google"
 import { TooltipProvider } from "@/components/ui/tooltip"
+import {
+  RUNTIME_CONFIG_GLOBAL,
+  readRuntimeConfig,
+  serializeRuntimeConfig,
+} from "@/lib/runtime-config"
 import "./globals.css"
 
+/**
+ * Required for runtime configuration to mean anything.
+ *
+ * Next prerenders a layout with no dynamic inputs at build time, which would
+ * evaluate readRuntimeConfig() during `next build` and bake that value into the
+ * HTML — reintroducing exactly the build-time freezing this replaces. Rendering
+ * per request is what lets GRAPH_MINDSET_API_URL be read from the live
+ * environment on every boot.
+ */
+export const dynamic = "force-dynamic"
+
 const rajdhani = Rajdhani({
   variable: "--font-heading",
   subsets: ["latin"],
@@ -51,6 +67,17 @@ export default function RootLayout({
       className={`${rajdhani.variable} ${jakarta.variable} ${firaCode.variable} h-full antialiased dark`}
     >
       <body className="h-full overflow-hidden">
+        {/*
+          Inline and first in the document so it runs during parse, before the
+          deferred application bundles — getApiUrl() therefore always sees it.
+        */}
+        <script
+          dangerouslySetInnerHTML={{
+            __html: `window.${RUNTIME_CONFIG_GLOBAL}=${serializeRuntimeConfig(
+              readRuntimeConfig()
+            )}`,
+          }}
+        />
         <div style={{ display: "none" }} data-ai-discovery="true">
           <h1>GraphMindset</h1>
           <p>

diff --git a/src/lib/agent-api.ts b/src/lib/agent-api.ts
@@ -1,6 +1,6 @@
 "use client"
 
-import { API_URL } from "./api"
+import { getApiUrl } from "./api"
 import { getSignedMessage, getL402, payL402 } from "./sphinx"
 import { useModalStore } from "@/stores/modal-store"
 import { isMocksEnabled } from "./mock-data"
@@ -60,7 +60,7 @@ function unwrapEnvelope(raw: string): { answer: string; cited_ref_ids: string[]
 
 // Builds a signed URL for a given API path
 async function buildSignedUrl(path: string): Promise<string> {
-  const url = new URL(`${API_URL}${path}`)
+  const url = new URL(`${getApiUrl()}${path}`)
   const signed = await getSignedMessage()
   if (signed.signature) {
     url.searchParams.append("sig", signed.signature)

diff --git a/src/lib/api.ts b/src/lib/api.ts
@@ -1,10 +1,27 @@
 import { getSignedMessage, getL402 } from "./sphinx"
+import { injectedApiUrl } from "./runtime-config"
 
 function resolveApiUrl(): string {
   if (typeof window === "undefined") {
-    return process.env.NEXT_PUBLIC_API_URL || "https://bitcoin.sphinx.chat/api"
+    // Server render: read the live environment directly. GRAPH_MINDSET_API_URL
+    // is not inlined at build time, so this reflects the running container.
+    return (
+      process.env.GRAPH_MINDSET_API_URL?.trim() ||
+      process.env.NEXT_PUBLIC_API_URL ||
+      "https://bitcoin.sphinx.chat/api"
+    )
   }
 
+  // Runtime value injected into the document by the root layout. Takes
+  // precedence over NEXT_PUBLIC_API_URL, which is only ever what happened to be
+  // set when the image was built.
+  const injected = injectedApiUrl()
+
+  if (injected) {
+    return injected
+  }
+
+  // Still honoured for builds that bake the URL in via --build-arg.
   if (process.env.NEXT_PUBLIC_API_URL) {
     return process.env.NEXT_PUBLIC_API_URL
   }
@@ -25,7 +42,21 @@ function resolveApiUrl(): string {
   return `${origin}/api`
 }
 
-export const API_URL = resolveApiUrl()
+let cachedApiUrl: string | undefined
+
+/**
+ * Resolved on first use rather than at module load, so the runtime value the
+ * root layout injects into the document is guaranteed to be in place by the
+ * time anything asks for it. Import this instead of a module-level constant.
+ */
+export function getApiUrl(): string {
+  return (cachedApiUrl ??= resolveApiUrl())
+}
+
+/** Test seam — forces the next getApiUrl() call to re-resolve. */
+export function resetApiUrlCache(): void {
+  cachedApiUrl = undefined
+}
 
 async function request<Res>(
   url: string,
@@ -74,7 +105,7 @@ export const api = {
     endpoint: string,
     headers?: RequestInit["headers"],
     signal?: AbortSignal
-  ) => request<Res>(`${API_URL}${endpoint}`, headers ? { headers } : undefined, signal),
+  ) => request<Res>(`${getApiUrl()}${endpoint}`, headers ? { headers } : undefined, signal),
 
   post: <Res>(
     endpoint: string,
@@ -83,7 +114,7 @@ export const api = {
     signal?: AbortSignal
   ) =>
     request<Res>(
-      `${API_URL}${endpoint}`,
+      `${getApiUrl()}${endpoint}`,
       {
         body: JSON.stringify(body),
         headers: { ...headers, "Content-Type": "application/json" },
@@ -99,7 +130,7 @@ export const api = {
     signal?: AbortSignal
   ) =>
     request<Res>(
-      `${API_URL}${endpoint}`,
+      `${getApiUrl()}${endpoint}`,
       {
         body: JSON.stringify(body),
         headers: { ...headers, "Content-Type": "application/json" },
@@ -114,7 +145,7 @@ export const api = {
     signal?: AbortSignal
   ) =>
     request<Res>(
-      `${API_URL}${endpoint}`,
+      `${getApiUrl()}${endpoint}`,
       {
         headers: { ...headers, "Content-Type": "application/json" },
         method: "DELETE",

diff --git a/src/lib/graph-api.ts b/src/lib/graph-api.ts
@@ -1,4 +1,4 @@
-import { api, API_URL } from "./api"
+import { api, getApiUrl } from "./api"
 import { getSignedMessage, getL402 } from "./sphinx"
 import { isMocksEnabled, MOCK_REVIEWS } from "./mock-data"
 
@@ -216,7 +216,7 @@ export async function uploadImageToNode(
   file: File,
   signal?: AbortSignal
 ): Promise<{ url: string; ref_id: string; status?: string }> {
-  const url = new URL(`${API_URL}/v2/nodes/${refId}/image`)
+  const url = new URL(`${getApiUrl()}/v2/nodes/${refId}/image`)
 
   // Sphinx-signed admin path piggybacks on query params (matches api.ts).
   const signed = await getSignedMessage()
@@ -284,7 +284,7 @@ export async function addImageContent(
   status_messages: string[]
   temp_url?: string
 }> {
-  const url = new URL(`${API_URL}/v2/content/image`)
+  const url = new URL(`${getApiUrl()}/v2/content/image`)
 
   const signed = await getSignedMessage()
   if (signed.signature) {
@@ -1219,7 +1219,7 @@ export async function addLegalDocumentFile(
   file: File,
   signal?: AbortSignal
 ): Promise<{ status: string; nodes: Array<Record<string, unknown>>; status_messages: string[] }> {
-  const url = new URL(`${API_URL}/v2/legal/upload`)
+  const url = new URL(`${getApiUrl()}/v2/legal/upload`)
 
   const signed = await getSignedMessage()
   if (signed.signature) {

diff --git a/src/lib/runtime-config.ts b/src/lib/runtime-config.ts
@@ -0,0 +1,64 @@
+/**
+ * Runtime configuration.
+ *
+ * NEXT_PUBLIC_* variables are inlined by Next at build time, so they freeze
+ * whatever value was present when the image was built. That makes a published
+ * image unusable in any deployment with a different API host — which is why
+ * the container could be handed the correct URL at runtime and still call the
+ * compiled-in default.
+ *
+ * GRAPH_MINDSET_API_URL carries no NEXT_PUBLIC_ prefix, so it is never inlined:
+ * the server reads it from the real environment on each boot and hands it to
+ * the browser through a <script> tag in the document head. One image then works
+ * in every environment, and changing the URL is a restart rather than a rebuild.
+ */
+
+export const RUNTIME_CONFIG_GLOBAL = "__GRAPH_MINDSET_CONFIG__"
+
+export type RuntimeConfig = {
+  apiUrl: string
+}
+
+declare global {
+  interface Window {
+    [RUNTIME_CONFIG_GLOBAL]?: Partial<RuntimeConfig>
+  }
+}
+
+/**
+ * Server-side only — reads the live environment. Called while rendering the
+ * document so the value is embedded in the HTML the browser receives.
+ */
+export function readRuntimeConfig(): RuntimeConfig {
+  return {
+    // GRAPH_MINDSET_API_URL is read from the live environment on every render.
+    //
+    // The NEXT_PUBLIC_API_URL fallback only ever yields the value baked in at
+    // build time — verified: starting this build with NEXT_PUBLIC_API_URL set to
+    // a fresh value still produced the compiled-in one, because Next inlines
+    // NEXT_PUBLIC_* in server code as well as client code. It is kept so images
+    // built with --build-arg keep working; it cannot carry a runtime value.
+    // Backwards compatibility for a swarm still setting the old name is handled
+    // in sphinx-swarm, which forwards it as GRAPH_MINDSET_API_URL.
+    apiUrl:
+      process.env.GRAPH_MINDSET_API_URL?.trim() ||
+      process.env.NEXT_PUBLIC_API_URL?.trim() ||
+      "",
+  }
+}
+
+/** The value injected into the document, or undefined when running server-side. */
+export function injectedApiUrl(): string | undefined {
+  if (typeof window === "undefined") {
+    return undefined
+  }
+
+  return window[RUNTIME_CONFIG_GLOBAL]?.apiUrl || undefined
+}
+
+/** Serialised for embedding in a <script> tag. */
+export function serializeRuntimeConfig(config: RuntimeConfig): string {
+  // JSON.stringify escapes quotes; guard the one sequence that could close the
+  // surrounding <script> element early.
+  return JSON.stringify(config).replace(/</g, "\\u003c")
+}
diff --git a/src/lib/socket.ts b/src/lib/socket.ts
@@ -1,12 +1,12 @@
 import { io, Socket } from 'socket.io-client'
-import { API_URL } from './api'
+import { getApiUrl } from './api'
 
 let socket: Socket | null = null
 
 export function getSocket(): Socket {
   if (typeof window === 'undefined') throw new Error('Socket not available in SSR')
   if (!socket) {
-    const url = API_URL.replace(/\/api$/, '')
+    const url = getApiUrl().replace(/\/api$/, '')
     socket = io(url, { transports: ['websocket'], autoConnect: true })
   }
   return socket