Add programmatic consent API to @probo/cookie-banner

Expose a ConsentManager singleton via `@probo/cookie-banner/consent`
(ESM) and `window.Probo.consent` (IIFE) so customers can check and
react to consent state in their bundled JavaScript code, solving the
problem of third-party SDKs initialized programmatically that cannot
be blocked via data-cookie-consent attributes.

Signed-off-by: Émile Ré <emile@getprobo.com>

packages/cookie-banner/build.mjs

@@ -38,6 +38,12 @@ await Promise.all([
     outfile: "dist/cookie-banner-headless.mjs",
     format: "esm",
   }),
+  esbuild.build({
+    ...shared,
+    entryPoints: ["src/consent.ts"],
+    outfile: "dist/cookie-banner-consent.mjs",
+    format: "esm",
+  }),
   esbuild.build({
     ...shared,
     entryPoints: ["src/themed-banner/iife.ts"],

packages/cookie-banner/package.json

@@ -16,6 +16,11 @@
       "types": "./dist/headless/index.d.ts",
       "import": "./dist/cookie-banner-headless.mjs",
       "default": "./dist/cookie-banner-headless.mjs"
+    },
+    "./consent": {
+      "types": "./dist/consent.d.ts",
+      "import": "./dist/cookie-banner-consent.mjs",
+      "default": "./dist/cookie-banner-consent.mjs"
     }
   },
   "scripts": {

packages/cookie-banner/src/client.ts

@@ -16,6 +16,7 @@ import {
   deactivateElements,
   observeAndActivate,
 } from "./activation";
+import { getConsent } from "./consent";
 import { COOKIE_NAME, getConsentCookie, setConsentCookie } from "./cookie";
 import type { Detector } from "./detectors";
 import { CookieDetector, ReportQueue, ResourceDetector, StorageDetector } from "./detectors";
@@ -109,6 +110,7 @@ export class CookieBannerClient {
         };
         this._gpcApplied = cookie.action === "GPC";
         this.activate(cookie.data);
+        getConsent()._setReady(cookie.data, true);
         void flush(this.bannerId);
         return;
       }
@@ -140,16 +142,24 @@ export class CookieBannerClient {
           config.consent_expiry_days,
         );
         this.activate(apiConsent.consent_data);
+        getConsent()._setReady(apiConsent.consent_data, true);
       } else {
         this.consent = null;
       }
     }
 
     if (!this.consent && this.gpcDetected) {
+      const gpcData: Record<string, boolean> = {};
+      for (const cat of config.categories) {
+        gpcData[cat.slug] = cat.kind === "NECESSARY";
+      }
+      getConsent()._setReady(gpcData, false);
       this.gpc();
       this._gpcApplied = true;
     } else if (!this.consent) {
-      this.activate(this.buildDefaultConsentData());
+      const defaults = this.buildDefaultConsentData();
+      this.activate(defaults);
+      getConsent()._setReady(defaults, false);
     }
 
     void flush(this.bannerId);
@@ -263,6 +273,7 @@ export class CookieBannerClient {
     );
 
     this.activate(consentData);
+    getConsent()._notify(consentData);
 
     const url = new URL(`${this.bannerId}/consents`, this.baseUrl);
     const body = {

packages/cookie-banner/src/consent.ts

@@ -0,0 +1,91 @@
+// Copyright (c) 2026 Probo Inc <hello@getprobo.com>.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+export type ConsentData = Record<string, boolean>;
+type Callback = (consent: ConsentData) => void;
+
+export class ConsentManager {
+  private _ready = false;
+  private _hasResponse = false;
+  private _consent: ConsentData = {};
+  private readonly _readyListeners: Callback[] = [];
+  private readonly _changeListeners: Callback[] = [];
+
+  get ready(): boolean {
+    return this._ready;
+  }
+
+  get hasResponse(): boolean {
+    return this._hasResponse;
+  }
+
+  has(category: string): boolean {
+    return !!this._consent[category];
+  }
+
+  getAll(): ConsentData {
+    return { ...this._consent };
+  }
+
+  onReady(cb: Callback): () => void {
+    if (this._ready) {
+      cb({ ...this._consent });
+      return () => {};
+    }
+    this._readyListeners.push(cb);
+    return () => {
+      const idx = this._readyListeners.indexOf(cb);
+      if (idx !== -1) this._readyListeners.splice(idx, 1);
+    };
+  }
+
+  onChange(cb: Callback): () => void {
+    this._changeListeners.push(cb);
+    return () => {
+      const idx = this._changeListeners.indexOf(cb);
+      if (idx !== -1) this._changeListeners.splice(idx, 1);
+    };
+  }
+
+  /** @internal Called by CookieBannerClient when consent state is first resolved. */
+  _setReady(consent: ConsentData, hasResponse: boolean): void {
+    this._consent = consent;
+    this._hasResponse = hasResponse;
+    this._ready = true;
+    for (const cb of this._readyListeners.splice(0)) {
+      cb({ ...this._consent });
+    }
+    for (const cb of this._changeListeners) {
+      cb({ ...this._consent });
+    }
+  }
+
+  /** @internal Called by CookieBannerClient when consent changes after user action. */
+  _notify(consent: ConsentData): void {
+    this._consent = consent;
+    this._hasResponse = true;
+    for (const cb of this._changeListeners) {
+      cb({ ...this._consent });
+    }
+  }
+}
+
+let instance: ConsentManager | null = null;
+
+export function getConsent(): ConsentManager {
+  if (!instance) {
+    instance = new ConsentManager();
+  }
+  return instance;
+}

packages/cookie-banner/src/themed-banner/iife.ts

@@ -12,10 +12,17 @@
 // OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 // PERFORMANCE OF THIS SOFTWARE.
 
+import { getConsent } from "../consent";
 import { registerCookieBanner } from "./index";
 
 registerCookieBanner();
 
+const w = window as unknown as Record<string, unknown>;
+if (!w.Probo) {
+  w.Probo = {};
+}
+(w.Probo as Record<string, unknown>).consent = getConsent();
+
 const script = document.currentScript as HTMLScriptElement | null;
 
 if (script) {