diff --git a/src/packages/next/lib/api/schema/projects/collaborators/remove.ts b/src/packages/next/lib/api/schema/projects/collaborators/remove.ts
index a1f0dcc238..f9aa7dedf5 100644
--- a/src/packages/next/lib/api/schema/projects/collaborators/remove.ts
+++ b/src/packages/next/lib/api/schema/projects/collaborators/remove.ts
@@ -3,14 +3,16 @@ import { z } from "../../../framework";
 import { FailedAPIOperationSchema, OkAPIOperationSchema } from "../../common";
 
 import { ProjectIdSchema } from "../common";
+import { AccountIdSchema } from "../../accounts/common";
 
 // OpenAPI spec
 //
 export const RemoveProjectCollaboratorInputSchema = z
   .object({
     project_id: ProjectIdSchema,
+    account_id: AccountIdSchema,
   })
-  .describe("Remove a collaborator from a project.");
+  .describe("Remove a collaborator from an existing project.");
 
 export const RemoveProjectCollaboratorOutputSchema = z.union([
   FailedAPIOperationSchema,
diff --git a/src/packages/next/pages/api/v2/projects/collaborators/add.ts b/src/packages/next/pages/api/v2/projects/collaborators/add.ts
index 0bd8ef805b..2bca1d39c7 100644
--- a/src/packages/next/pages/api/v2/projects/collaborators/add.ts
+++ b/src/packages/next/pages/api/v2/projects/collaborators/add.ts
@@ -40,10 +40,10 @@ async function handle(req, res) {
 }
 
 export default apiRoute({
-  add: apiRouteOperation({
+  addProjectCollaborator: apiRouteOperation({
     method: "POST",
     openApiOperation: {
-      tags: ["Projects", "Administrators"],
+      tags: ["Projects", "Admin"],
     },
   })
     .input({
diff --git a/src/packages/next/pages/api/v2/projects/collaborators/remove.ts b/src/packages/next/pages/api/v2/projects/collaborators/remove.ts
new file mode 100644
index 0000000000..7db70220a7
--- /dev/null
+++ b/src/packages/next/pages/api/v2/projects/collaborators/remove.ts
@@ -0,0 +1,61 @@
+/*
+API endpoint to remove a user from an existing project.
+
+Permissions checks are performed by the underlying API call and are NOT
+executed at this stage.
+
+*/
+import { db } from "@cocalc/database";
+import { remove_collaborators_from_projects } from "@cocalc/server/projects/collab";
+
+import getAccountId from "lib/account/get-account";
+import getParams from "lib/api/get-params";
+import { apiRoute, apiRouteOperation } from "lib/api";
+import { OkStatus } from "lib/api/status";
+import {
+  RemoveProjectCollaboratorInputSchema,
+  RemoveProjectCollaboratorOutputSchema,
+} from "lib/api/schema/projects/collaborators/remove";
+
+async function handle(req, res) {
+  const { project_id, account_id } = getParams(req);
+  const client_account_id = await getAccountId(req);
+
+  try {
+    if (!client_account_id) {
+      throw Error("must be signed in");
+    }
+
+    await remove_collaborators_from_projects(
+      db(),
+      client_account_id,
+      [account_id],
+      [project_id],
+    );
+
+    res.json(OkStatus);
+  } catch (err) {
+    res.json({ error: err.message });
+  }
+}
+
+export default apiRoute({
+  removeProjectCollaborator: apiRouteOperation({
+    method: "POST",
+    openApiOperation: {
+      tags: ["Projects", "Admin"],
+    },
+  })
+    .input({
+      contentType: "application/json",
+      body: RemoveProjectCollaboratorInputSchema,
+    })
+    .outputs([
+      {
+        status: 200,
+        contentType: "application/json",
+        body: RemoveProjectCollaboratorOutputSchema,
+      },
+    ])
+    .handler(handle),
+});
diff --git a/src/packages/next/pages/api/v2/shopping/cart/add.ts b/src/packages/next/pages/api/v2/shopping/cart/add.ts
index 77341a2e89..8be37c4216 100644
--- a/src/packages/next/pages/api/v2/shopping/cart/add.ts
+++ b/src/packages/next/pages/api/v2/shopping/cart/add.ts
@@ -52,7 +52,7 @@ async function add(req): Promise<number | undefined> {
 }
 
 export default apiRoute({
-  add: apiRouteOperation({
+  addCartItem: apiRouteOperation({
     method: "POST",
     openApiOperation: {
       tags: ["Shopping"],
diff --git a/src/packages/server/projects/collab.ts b/src/packages/server/projects/collab.ts
index 1797bf5eff..c638f2f9ec 100644
--- a/src/packages/server/projects/collab.ts
+++ b/src/packages/server/projects/collab.ts
@@ -67,6 +67,44 @@ export async function add_collaborators_to_projects(
   }
 }
 
+export async function remove_collaborators_from_projects(
+  db: PostgreSQL,
+  account_id: string,
+  accounts: string[],
+  projects: string[], // can be empty strings if tokens specified (since they determine project_id)
+): Promise<void> {
+  try {
+    // Ensure user is allowed to modify project(s)
+    //
+    await verify_write_access_to_projects(db, account_id, projects);
+  } catch (err) {
+    // Users can always remove themselves from a project.
+    //
+    if (accounts.length == 1 && account_id == accounts[0]) {
+      await verify_course_access_to_project(db, account_id, projects[0]);
+    } else {
+      throw err;
+    }
+  }
+
+  /* Right now this function is called from outside typescript
+    (e.g., api from user), so we have to do extra type checking.
+    Also, the input is uuid's, which typescript can't check. */
+  verify_types(account_id, accounts, projects);
+
+  // Remove users from projects
+  //
+  for (const i in projects) {
+    const project_id: string = projects[i];
+    const account_id: string = accounts[i];
+
+    await callback2(db.remove_user_from_project, {
+      project_id,
+      account_id,
+    });
+  }
+}
+
 // This is only meant to be used here in support of
 // add_collaborators_to_projects -- do not export it.
 async function verify_write_access_to_projects(