diff --git a/app/src/components/composio/ComposioConnectModal.tsx b/app/src/components/composio/ComposioConnectModal.tsx
index 846c5072b..8ae03d4bd 100644
--- a/app/src/components/composio/ComposioConnectModal.tsx
+++ b/app/src/components/composio/ComposioConnectModal.tsx
@@ -13,7 +13,7 @@
  * keep the Skills page badge in sync too, so the card reflects the new
  * state as soon as the modal closes.
  */
-import { useCallback, useEffect, useRef, useState } from 'react';
+import { type ChangeEvent, useCallback, useEffect, useRef, useState } from 'react';
 import { createPortal } from 'react-dom';
 
 import {
@@ -73,6 +73,9 @@ export default function ComposioConnectModal({
   );
   const [error, setError] = useState<string | null>(null);
   const [connectUrl, setConnectUrl] = useState<string | null>(null);
+  // WhatsApp Business requires a WABA ID before the OAuth flow can start.
+  const [wabaId, setWabaId] = useState('');
+  const needsWabaId = toolkit.slug === 'whatsapp';
   const [activeConnection, setActiveConnection] = useState<ComposioConnection | undefined>(
     connection
   );
@@ -188,11 +191,16 @@ export default function ComposioConnectModal({
   }, []);
 
   const handleConnect = useCallback(async () => {
+    if (needsWabaId && !wabaId.trim()) {
+      setError('Please enter your WhatsApp Business Account ID (WABA ID) to continue.');
+      return;
+    }
     setPhase('authorizing');
     setError(null);
     setConnectUrl(null);
     try {
-      const resp = await authorize(toolkit.slug);
+      const extraParams = needsWabaId ? { waba_id: wabaId.trim() } : undefined;
+      const resp = await authorize(toolkit.slug, extraParams);
       setConnectUrl(resp.connectUrl);
       await openUrl(resp.connectUrl);
       setPhase('waiting');
@@ -202,7 +210,7 @@ export default function ComposioConnectModal({
       setPhase('error');
       setError(`Authorization failed: ${msg}`);
     }
-  }, [startPolling, toolkit.slug]);
+  }, [needsWabaId, startPolling, toolkit.slug, wabaId]);
 
   // Fetch the stored scope pref whenever the modal lands in the
   // 'connected' phase. Re-fetching each time we transition (rather
@@ -360,6 +368,35 @@ export default function ComposioConnectModal({
                   admin toggles.
                 </p>
               </div>
+              {needsWabaId && (
+                <div className="space-y-1.5">
+                  <label
+                    htmlFor="waba-id-input"
+                    className="block text-xs font-medium text-stone-700">
+                    WhatsApp Business Account ID (WABA ID)
+                    <span className="ml-1 text-coral-500">*</span>
+                  </label>
+                  <input
+                    id="waba-id-input"
+                    type="text"
+                    value={wabaId}
+                    onChange={(e: ChangeEvent<HTMLInputElement>) => {
+                      setWabaId(e.target.value);
+                      if (error) setError(null);
+                    }}
+                    placeholder="e.g. 123456789012345"
+                    className="w-full rounded-xl border border-stone-200 bg-white px-3 py-2 text-sm text-stone-900 placeholder:text-stone-400 focus:border-primary-400 focus:outline-none focus:ring-2 focus:ring-primary-100"
+                  />
+                  <p className="text-[11px] leading-relaxed text-stone-400">
+                    Find it via <span className="font-mono">GET /me/businesses</span> then{' '}
+                    <span className="font-mono">
+                      GET /&#123;business_id&#125;/owned_whatsapp_business_accounts
+                    </span>{' '}
+                    using your Meta access token.
+                  </p>
+                </div>
+              )}
+              {error && phase === 'idle' && <p className="text-[11px] text-coral-600">{error}</p>}
               <button
                 type="button"
                 onClick={() => void handleConnect()}
diff --git a/app/src/lib/composio/composioApi.ts b/app/src/lib/composio/composioApi.ts
index 14b0355e9..e8502b3e3 100644
--- a/app/src/lib/composio/composioApi.ts
+++ b/app/src/lib/composio/composioApi.ts
@@ -73,11 +73,17 @@ export async function listTools(toolkits?: string[]): Promise<ComposioToolsRespo
  * Begin an OAuth handoff for `toolkit`. The returned `connectUrl`
  * must be opened in a browser for the user to complete the flow.
  * The core publishes a `ComposioConnectionCreated` event on success.
+ *
+ * `extraParams` is merged into the backend request body. Required for
+ * toolkits that need additional fields (e.g. `whatsapp` needs `waba_id`).
  */
-export async function authorize(toolkit: string): Promise<ComposioAuthorizeResponse> {
+export async function authorize(
+  toolkit: string,
+  extraParams?: Record<string, string>
+): Promise<ComposioAuthorizeResponse> {
   const raw = await callCoreRpc<unknown>({
     method: 'openhuman.composio_authorize',
-    params: { toolkit },
+    params: extraParams ? { toolkit, extra_params: extraParams } : { toolkit },
   });
   return unwrapCliEnvelope<ComposioAuthorizeResponse>(raw);
 }
diff --git a/src/openhuman/composio/client.rs b/src/openhuman/composio/client.rs
index 482e6b421..d12b40613 100644
--- a/src/openhuman/composio/client.rs
+++ b/src/openhuman/composio/client.rs
@@ -65,13 +65,39 @@ impl ComposioClient {
     /// `POST /agent-integrations/composio/authorize` — begin an OAuth
     /// handoff for `toolkit` and return the hosted `connectUrl` the user
     /// must open in a browser.
-    pub async fn authorize(&self, toolkit: &str) -> Result<ComposioAuthorizeResponse> {
+    ///
+    /// `extra_params` is an optional JSON object whose key/value pairs are
+    /// merged into the request body. Some toolkits (e.g. `whatsapp`) require
+    /// additional fields (e.g. `waba_id`) that Composio will reject the
+    /// authorization without.
+    pub async fn authorize(
+        &self,
+        toolkit: &str,
+        extra_params: Option<serde_json::Value>,
+    ) -> Result<ComposioAuthorizeResponse> {
         let toolkit = toolkit.trim();
         if toolkit.is_empty() {
             anyhow::bail!("composio.authorize: toolkit must not be empty");
         }
-        tracing::debug!(toolkit = %toolkit, "[composio] authorize");
-        let body = json!({ "toolkit": toolkit });
+        tracing::debug!(toolkit = %toolkit, has_extra_params = extra_params.is_some(), "[composio] authorize");
+        let mut body = serde_json::json!({ "toolkit": toolkit });
+        if let Some(extra) = extra_params {
+            const RESERVED: &[&str] = &["toolkit", "toolkit_version", "auth", "client_id"];
+            let extra_obj = extra.as_object().ok_or_else(|| {
+                anyhow::anyhow!("composio.authorize: extra_params must be a JSON object")
+            })?;
+            let obj = body.as_object_mut().ok_or_else(|| {
+                anyhow::anyhow!("composio.authorize: internal payload must be an object")
+            })?;
+            for (k, v) in extra_obj {
+                if RESERVED.contains(&k.as_str()) {
+                    anyhow::bail!(
+                        "composio.authorize: extra_params cannot override reserved key '{k}'"
+                    );
+                }
+                obj.insert(k.clone(), v.clone());
+            }
+        }
         self.inner
             .post::<ComposioAuthorizeResponse>("/agent-integrations/composio/authorize", &body)
             .await
diff --git a/src/openhuman/composio/client_tests.rs b/src/openhuman/composio/client_tests.rs
index 5672bfccc..d867fa58d 100644
--- a/src/openhuman/composio/client_tests.rs
+++ b/src/openhuman/composio/client_tests.rs
@@ -41,13 +41,50 @@ async fn authorize_rejects_empty_toolkit() {
         "test".into(),
     ));
     let client = ComposioClient::new(inner);
-    let err = client.authorize("   ").await.unwrap_err();
+    let err = client.authorize("   ", None).await.unwrap_err();
     assert!(
         err.to_string().contains("toolkit must not be empty"),
         "unexpected error: {err}"
     );
 }
 
+/// `authorize()` must reject a non-object `extra_params` before making any HTTP call.
+#[tokio::test]
+async fn authorize_rejects_non_object_extra_params() {
+    let inner = Arc::new(crate::openhuman::integrations::IntegrationClient::new(
+        "http://127.0.0.1:0".into(),
+        "test".into(),
+    ));
+    let client = ComposioClient::new(inner);
+    let err = client
+        .authorize("whatsapp", Some(serde_json::json!("waba-123")))
+        .await
+        .unwrap_err();
+    assert!(
+        err.to_string()
+            .contains("extra_params must be a JSON object"),
+        "unexpected error: {err}"
+    );
+}
+
+/// `authorize()` must reject an `extra_params` object that tries to override a reserved key.
+#[tokio::test]
+async fn authorize_rejects_reserved_key_override() {
+    let inner = Arc::new(crate::openhuman::integrations::IntegrationClient::new(
+        "http://127.0.0.1:0".into(),
+        "test".into(),
+    ));
+    let client = ComposioClient::new(inner);
+    let err = client
+        .authorize("whatsapp", Some(serde_json::json!({ "toolkit": "gmail" })))
+        .await
+        .unwrap_err();
+    assert!(
+        err.to_string().contains("cannot override reserved key"),
+        "unexpected error: {err}"
+    );
+}
+
 /// `delete_connection()` likewise must reject empty connection ids.
 #[tokio::test]
 async fn delete_connection_rejects_empty_id() {
@@ -191,11 +228,36 @@ async fn authorize_posts_toolkit_and_returns_connect_url() {
     );
     let base = start_mock_backend(app).await;
     let client = build_client_for(base);
-    let resp = client.authorize("gmail").await.unwrap();
+    let resp = client.authorize("gmail", None).await.unwrap();
     assert!(resp.connect_url.contains("gmail"));
     assert_eq!(resp.connection_id, "conn-abc");
 }
 
+#[tokio::test]
+async fn authorize_forwards_extra_params_and_returns_connect_url() {
+    let app = Router::new().route(
+        "/agent-integrations/composio/authorize",
+        post(|Json(body): Json<Value>| async move {
+            // Assert extra_params are forwarded alongside toolkit.
+            assert_eq!(body["toolkit"].as_str(), Some("whatsapp"));
+            assert_eq!(body["waba_id"].as_str(), Some("waba-123"));
+            Json(json!({
+                "success": true,
+                "data": {
+                    "connectUrl": "https://composio.example/whatsapp/consent",
+                    "connectionId": "conn-xyz"
+                }
+            }))
+        }),
+    );
+    let base = start_mock_backend(app).await;
+    let client = build_client_for(base);
+    let extra = serde_json::json!({ "waba_id": "waba-123" });
+    let resp = client.authorize("whatsapp", Some(extra)).await.unwrap();
+    assert!(resp.connect_url.contains("whatsapp"));
+    assert_eq!(resp.connection_id, "conn-xyz");
+}
+
 #[tokio::test]
 async fn list_tools_filters_pass_through_as_csv_query_param() {
     let app = Router::new().route(
diff --git a/src/openhuman/composio/ops.rs b/src/openhuman/composio/ops.rs
index caf5fb92f..942778742 100644
--- a/src/openhuman/composio/ops.rs
+++ b/src/openhuman/composio/ops.rs
@@ -97,11 +97,12 @@ pub async fn composio_list_connections(
 pub async fn composio_authorize(
     config: &Config,
     toolkit: &str,
+    extra_params: Option<serde_json::Value>,
 ) -> OpResult<RpcOutcome<ComposioAuthorizeResponse>> {
-    tracing::debug!(toolkit = %toolkit, "[composio] rpc authorize");
+    tracing::debug!(toolkit = %toolkit, has_extra_params = extra_params.is_some(), "[composio] rpc authorize");
     let client = resolve_client(config)?;
     let resp = client
-        .authorize(toolkit)
+        .authorize(toolkit, extra_params)
         .await
         .map_err(|e| format!("[composio] authorize failed: {e:#}"))?;
 
diff --git a/src/openhuman/composio/ops_tests.rs b/src/openhuman/composio/ops_tests.rs
index daa6b3dbe..5d8f4c83a 100644
--- a/src/openhuman/composio/ops_tests.rs
+++ b/src/openhuman/composio/ops_tests.rs
@@ -69,7 +69,9 @@ async fn composio_list_connections_errors_without_session() {
 async fn composio_authorize_errors_without_session() {
     let tmp = tempfile::tempdir().unwrap();
     let config = test_config(&tmp);
-    let err = composio_authorize(&config, "gmail").await.unwrap_err();
+    let err = composio_authorize(&config, "gmail", None)
+        .await
+        .unwrap_err();
     assert!(err.contains("composio unavailable"));
 }
 
@@ -291,7 +293,7 @@ async fn composio_authorize_via_mock_publishes_event_and_returns_url() {
     let base = start_mock_backend(app).await;
     let tmp = tempfile::tempdir().unwrap();
     let config = config_with_backend(&tmp, base);
-    let outcome = composio_authorize(&config, "gmail").await.unwrap();
+    let outcome = composio_authorize(&config, "gmail", None).await.unwrap();
     assert_eq!(outcome.value.connect_url, "https://x");
     assert_eq!(outcome.value.connection_id, "c1");
 }
diff --git a/src/openhuman/composio/schemas.rs b/src/openhuman/composio/schemas.rs
index 03e9680a2..729bb129f 100644
--- a/src/openhuman/composio/schemas.rs
+++ b/src/openhuman/composio/schemas.rs
@@ -188,12 +188,22 @@ pub fn schemas(function: &str) -> ControllerSchema {
             namespace: "composio",
             function: "authorize",
             description: "Begin an OAuth handoff for a toolkit and return the hosted connect URL.",
-            inputs: vec![FieldSchema {
-                name: "toolkit",
-                ty: TypeSchema::String,
-                comment: "Toolkit slug to authorize (must be in the backend allowlist).",
-                required: true,
-            }],
+            inputs: vec![
+                FieldSchema {
+                    name: "toolkit",
+                    ty: TypeSchema::String,
+                    comment: "Toolkit slug to authorize (must be in the backend allowlist).",
+                    required: true,
+                },
+                FieldSchema {
+                    name: "extra_params",
+                    ty: TypeSchema::Json,
+                    comment: "Optional JSON object of additional auth fields forwarded to Composio \
+                              (e.g. {\"waba_id\": \"...\") for toolkits that require them). \
+                              Reserved keys (toolkit, toolkit_version, auth, client_id) are rejected.",
+                    required: false,
+                },
+            ],
             outputs: vec![
                 FieldSchema {
                     name: "connectUrl",
@@ -601,7 +611,8 @@ fn handle_authorize(params: Map<String, Value>) -> ControllerFuture {
     Box::pin(async move {
         let config = config_rpc::load_config_with_timeout().await?;
         let toolkit = read_required_non_empty(&params, "toolkit")?;
-        to_json(super::ops::composio_authorize(&config, &toolkit).await?)
+        let extra_params = params.get("extra_params").cloned();
+        to_json(super::ops::composio_authorize(&config, &toolkit, extra_params).await?)
     })
 }
 
diff --git a/src/openhuman/composio/tools.rs b/src/openhuman/composio/tools.rs
index 659ae74ca..4f5a65dc0 100644
--- a/src/openhuman/composio/tools.rs
+++ b/src/openhuman/composio/tools.rs
@@ -422,7 +422,7 @@ impl Tool for ComposioAuthorizeTool {
             ));
         }
         tracing::debug!(toolkit = %toolkit, "[composio] tool authorize.execute");
-        match self.client.authorize(&toolkit).await {
+        match self.client.authorize(&toolkit, None).await {
             Ok(resp) => {
                 crate::core::event_bus::publish_global(
                     crate::core::event_bus::DomainEvent::ComposioConnectionCreated {