From ed43ffe772435ccd42b436e512943959f499a976 Mon Sep 17 00:00:00 2001
From: eddymarc <132223353+Edd88-pixel@users.noreply.github.com>
Date: Mon, 29 Jun 2026 23:38:02 +0100
Subject: [PATCH 1/4] fix(jupyter): bind notebook services to loopback

---
 .../coder/modules/jupyter-notebook/README.md  | 24 +++++-
 .../modules/jupyter-notebook/main.test.ts     | 86 +++++++++++++++++++
 .../coder/modules/jupyter-notebook/main.tf    | 12 +++
 .../modules/jupyter-notebook/main.tftest.hcl  | 54 ++++++++++++
 .../coder/modules/jupyter-notebook/run.sh     |  8 +-
 registry/coder/modules/jupyterlab/README.md   | 26 +++++-
 .../coder/modules/jupyterlab/main.test.ts     | 70 ++++++++++++++-
 registry/coder/modules/jupyterlab/main.tf     | 12 +++
 .../coder/modules/jupyterlab/main.tftest.hcl  | 84 ++++++++++++++++++
 registry/coder/modules/jupyterlab/run.sh      |  6 +-
 10 files changed, 374 insertions(+), 8 deletions(-)
 create mode 100644 registry/coder/modules/jupyter-notebook/main.test.ts
 create mode 100644 registry/coder/modules/jupyter-notebook/main.tftest.hcl
 create mode 100644 registry/coder/modules/jupyterlab/main.tftest.hcl

diff --git a/registry/coder/modules/jupyter-notebook/README.md b/registry/coder/modules/jupyter-notebook/README.md
index ea625d812..7de146d4d 100644
--- a/registry/coder/modules/jupyter-notebook/README.md
+++ b/registry/coder/modules/jupyter-notebook/README.md
@@ -12,11 +12,33 @@ A module that adds Jupyter Notebook in your Coder template.
 
 ![Jupyter Notebook](../../.images/jupyter-notebook.png)
 
+Jupyter Notebook listens on `127.0.0.1` by default so that unauthenticated
+traffic must pass through Coder's application proxy.
+
+## Usage
+
+```tf
+module "jupyter-notebook" {
+  count    = data.coder_workspace.me.start_count
+  source   = "registry.coder.com/coder/jupyter-notebook/coder"
+  version  = "1.3.0"
+  agent_id = coder_agent.main.id
+}
+```
+
+## External network access
+
+> [!WARNING]
+> For advanced environments that require direct network access, set `host`
+> explicitly. Binding to `0.0.0.0` exposes the unauthenticated service to every
+> reachable network interface and is less secure.
+
 ```tf
 module "jupyter-notebook" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/jupyter-notebook/coder"
-  version  = "1.2.1"
+  version  = "1.3.0"
   agent_id = coder_agent.main.id
+  host     = "0.0.0.0"
 }
 ```
diff --git a/registry/coder/modules/jupyter-notebook/main.test.ts b/registry/coder/modules/jupyter-notebook/main.test.ts
new file mode 100644
index 000000000..6c5f76e3d
--- /dev/null
+++ b/registry/coder/modules/jupyter-notebook/main.test.ts
@@ -0,0 +1,86 @@
+import { describe, expect, it, setDefaultTimeout } from "bun:test";
+import {
+  execContainer,
+  findResourceInstance,
+  readFileContainer,
+  removeContainer,
+  runContainer,
+  runTerraformApply,
+  runTerraformInit,
+  testRequiredVariables,
+  writeFileContainer,
+} from "~test";
+
+setDefaultTimeout(30_000);
+
+describe("jupyter-notebook", async () => {
+  await runTerraformInit(import.meta.dir);
+
+  testRequiredVariables(import.meta.dir, {
+    agent_id: "foo",
+  });
+
+  it("binds to loopback by default", async () => {
+    const state = await runTerraformApply(import.meta.dir, {
+      agent_id: "foo",
+    });
+    const script = findResourceInstance(state, "coder_script").script;
+
+    expect(script).toContain("--NotebookApp.ip='127.0.0.1'");
+    expect(script).not.toContain("0.0.0.0");
+    expect(script).not.toContain("--NotebookApp.ip='*'");
+    expect(script).not.toContain("--ServerApp.ip='*'");
+
+    const id = await runContainer("alpine");
+    try {
+      await execContainer(id, ["mkdir", "-p", "/root/.local/bin"]);
+      await writeFileContainer(
+        id,
+        "/root/.local/bin/jupyter-notebook",
+        "#!/bin/sh\nprintf '%s\\n' \"$@\" > /tmp/jupyter-args\n",
+      );
+      await execContainer(id, [
+        "chmod",
+        "755",
+        "/root/.local/bin/jupyter-notebook",
+      ]);
+      const result = await execContainer(
+        id,
+        ["sh", "-c", script],
+        [
+          "--env",
+          "PATH=/root/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
+        ],
+      );
+      expect(result.exitCode).toBe(0);
+      const args = await readFileContainer(id, "/tmp/jupyter-args");
+      expect(args).toContain("--NotebookApp.ip=127.0.0.1");
+    } finally {
+      await removeContainer(id);
+    }
+  });
+
+  it("renders an explicit external host", async () => {
+    const state = await runTerraformApply(import.meta.dir, {
+      agent_id: "foo",
+      host: "0.0.0.0",
+    });
+    const script = findResourceInstance(state, "coder_script").script;
+    expect(script).toContain("--NotebookApp.ip='0.0.0.0'");
+  });
+
+  for (const unsafeHost of [
+    "127.0.0.1; touch /tmp/injected",
+    "127.0.0.1 $(id)",
+    "127.0.0.1`id`",
+    "127.0.0.1'quoted",
+  ]) {
+    it(`rejects unsafe host ${JSON.stringify(unsafeHost)}`, async () => {
+      const apply = runTerraformApply(import.meta.dir, {
+        agent_id: "foo",
+        host: unsafeHost,
+      });
+      await expect(apply).rejects.toThrow("host must contain only");
+    });
+  }
+});
diff --git a/registry/coder/modules/jupyter-notebook/main.tf b/registry/coder/modules/jupyter-notebook/main.tf
index 568e8ca7a..d1843bd0d 100644
--- a/registry/coder/modules/jupyter-notebook/main.tf
+++ b/registry/coder/modules/jupyter-notebook/main.tf
@@ -21,6 +21,17 @@ variable "log_path" {
   default     = "/tmp/jupyter-notebook.log"
 }
 
+variable "host" {
+  description = "The host address that Jupyter Notebook listens on."
+  type        = string
+  default     = "127.0.0.1"
+
+  validation {
+    condition     = can(regex("^[A-Za-z0-9](?:[A-Za-z0-9.-]*[A-Za-z0-9])?$", var.host))
+    error_message = "host must contain only letters, numbers, dots, and hyphens, and must start and end with a letter or number."
+  }
+}
+
 variable "port" {
   type        = number
   description = "The port to run jupyter-notebook on."
@@ -66,6 +77,7 @@ resource "coder_script" "jupyter-notebook" {
   icon         = "/icon/jupyter.svg"
   script = templatefile("${path.module}/run.sh", {
     LOG_PATH : var.log_path,
+    HOST : var.host,
     PORT : var.port,
     REQUIREMENTS_PATH : var.requirements_path,
     PIP_INSTALL_EXTRA_PACKAGES : var.pip_install_extra_packages
diff --git a/registry/coder/modules/jupyter-notebook/main.tftest.hcl b/registry/coder/modules/jupyter-notebook/main.tftest.hcl
new file mode 100644
index 000000000..ffb1a779f
--- /dev/null
+++ b/registry/coder/modules/jupyter-notebook/main.tftest.hcl
@@ -0,0 +1,54 @@
+run "secure_defaults" {
+  command = plan
+
+  variables {
+    agent_id = "test-agent-id"
+  }
+
+  assert {
+    condition     = var.host == "127.0.0.1"
+    error_message = "host must default to 127.0.0.1"
+  }
+
+  assert {
+    condition     = strcontains(coder_script.jupyter-notebook.script, "--NotebookApp.ip='127.0.0.1'")
+    error_message = "the default script must bind Jupyter Notebook to 127.0.0.1"
+  }
+
+  assert {
+    condition     = !strcontains(coder_script.jupyter-notebook.script, "0.0.0.0") && !strcontains(coder_script.jupyter-notebook.script, "--NotebookApp.ip='*'") && !strcontains(coder_script.jupyter-notebook.script, "--ServerApp.ip='*'")
+    error_message = "the default script must not bind Jupyter Notebook to all interfaces"
+  }
+
+  assert {
+    condition     = coder_app.jupyter-notebook.url == "http://localhost:19999"
+    error_message = "the default Coder application URL must remain unchanged"
+  }
+}
+
+run "explicit_external_host" {
+  command = plan
+
+  variables {
+    agent_id = "test-agent-id"
+    host     = "0.0.0.0"
+  }
+
+  assert {
+    condition     = strcontains(coder_script.jupyter-notebook.script, "--NotebookApp.ip='0.0.0.0'")
+    error_message = "the script must render an explicitly configured host"
+  }
+}
+
+run "unsafe_host_rejected" {
+  command = plan
+
+  variables {
+    agent_id = "test-agent-id"
+    host     = "127.0.0.1; touch /tmp/injected"
+  }
+
+  expect_failures = [
+    var.host,
+  ]
+}
diff --git a/registry/coder/modules/jupyter-notebook/run.sh b/registry/coder/modules/jupyter-notebook/run.sh
index 797d9b41f..36559ec86 100644
--- a/registry/coder/modules/jupyter-notebook/run.sh
+++ b/registry/coder/modules/jupyter-notebook/run.sh
@@ -40,4 +40,10 @@ fi
 
 echo "👷 Starting jupyter-notebook in background..."
 echo "check logs at ${LOG_PATH}"
-$HOME/.local/bin/jupyter-notebook --NotebookApp.ip='0.0.0.0' --ServerApp.port=${PORT} --no-browser --ServerApp.token='' --ServerApp.password='' > ${LOG_PATH} 2>&1 &
+"$HOME/.local/bin/jupyter-notebook" \
+  --NotebookApp.ip='${HOST}' \
+  --ServerApp.port='${PORT}' \
+  --no-browser \
+  --ServerApp.token='' \
+  --ServerApp.password='' \
+  > "${LOG_PATH}" 2>&1 &
diff --git a/registry/coder/modules/jupyterlab/README.md b/registry/coder/modules/jupyterlab/README.md
index 0e2b7dcf8..bf0f77e19 100644
--- a/registry/coder/modules/jupyterlab/README.md
+++ b/registry/coder/modules/jupyterlab/README.md
@@ -12,12 +12,34 @@ A module that adds JupyterLab in your Coder template.
 
 ![JupyterLab](../../.images/jupyterlab.png)
 
+JupyterLab listens on `127.0.0.1` by default so that unauthenticated traffic
+must pass through Coder's application proxy.
+
+## Usage
+
+```tf
+module "jupyterlab" {
+  count    = data.coder_workspace.me.start_count
+  source   = "registry.coder.com/coder/jupyterlab/coder"
+  version  = "1.3.0"
+  agent_id = coder_agent.main.id
+}
+```
+
+## External network access
+
+> [!WARNING]
+> For advanced environments that require direct network access, set `host`
+> explicitly. Binding to `0.0.0.0` exposes the unauthenticated service to every
+> reachable network interface and is less secure.
+
 ```tf
 module "jupyterlab" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/jupyterlab/coder"
-  version  = "1.2.2"
+  version  = "1.3.0"
   agent_id = coder_agent.main.id
+  host     = "0.0.0.0"
 }
 ```
 
@@ -29,7 +51,7 @@ JupyterLab is automatically configured to work with Coder's iframe embedding. Fo
 module "jupyterlab" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/jupyterlab/coder"
-  version  = "1.2.2"
+  version  = "1.3.0"
   agent_id = coder_agent.main.id
   config = {
     ServerApp = {
diff --git a/registry/coder/modules/jupyterlab/main.test.ts b/registry/coder/modules/jupyterlab/main.test.ts
index 681188ca3..721cfafb0 100644
--- a/registry/coder/modules/jupyterlab/main.test.ts
+++ b/registry/coder/modules/jupyterlab/main.test.ts
@@ -1,4 +1,4 @@
-import { describe, expect, it } from "bun:test";
+import { describe, expect, it, setDefaultTimeout } from "bun:test";
 import {
   execContainer,
   executeScriptInContainer,
@@ -10,8 +10,11 @@ import {
   runTerraformInit,
   testRequiredVariables,
   type TerraformState,
+  writeFileContainer,
 } from "~test";
 
+setDefaultTimeout(30_000);
+
 // executes the coder script after installing pip
 const executeScriptInContainerWithPip = async (
   state: TerraformState,
@@ -166,4 +169,69 @@ describe("jupyterlab", async () => {
     );
     expect(configScripts.length).toBe(1);
   });
+
+  it("binds to loopback by default without changing Coder URLs", async () => {
+    const state = await runTerraformApply(import.meta.dir, {
+      agent_id: "foo",
+    });
+    const script = findResourceInstance(
+      state,
+      "coder_script",
+      "jupyterlab",
+    ).script;
+    const app = findResourceInstance(state, "coder_app", "jupyterlab");
+
+    expect(script).toContain("--ServerApp.ip='127.0.0.1'");
+    expect(script).not.toContain("0.0.0.0");
+    expect(script).not.toContain("--ServerApp.ip='*'");
+    expect(app.url).toBe("http://localhost:19999");
+
+    const id = await runContainer("alpine");
+    try {
+      await writeFileContainer(
+        id,
+        "/usr/local/bin/jupyter-lab",
+        "#!/bin/sh\nprintf '%s\\n' \"$@\" > /tmp/jupyter-args\n",
+      );
+      await execContainer(id, ["chmod", "755", "/usr/local/bin/jupyter-lab"]);
+      const result = await execContainer(id, ["sh", "-c", script]);
+      expect(result.exitCode).toBe(0);
+      const args = await readFileContainer(id, "/tmp/jupyter-args");
+      expect(args).toContain("--ServerApp.ip=127.0.0.1");
+    } finally {
+      await removeContainer(id);
+    }
+  });
+
+  it("preserves path mode and renders an explicit external host", async () => {
+    const state = await runTerraformApply(import.meta.dir, {
+      agent_id: "foo",
+      host: "0.0.0.0",
+      subdomain: false,
+    });
+    const script = findResourceInstance(
+      state,
+      "coder_script",
+      "jupyterlab",
+    ).script;
+
+    expect(script).toContain("--ServerApp.ip='0.0.0.0'");
+    expect(script).toContain("--ServerApp.base_url=/@");
+    expect(script).toContain("/apps/jupyterlab");
+  });
+
+  for (const unsafeHost of [
+    "127.0.0.1; touch /tmp/injected",
+    "127.0.0.1 $(id)",
+    "127.0.0.1`id`",
+    "127.0.0.1'quoted",
+  ]) {
+    it(`rejects unsafe host ${JSON.stringify(unsafeHost)}`, async () => {
+      const apply = runTerraformApply(import.meta.dir, {
+        agent_id: "foo",
+        host: unsafeHost,
+      });
+      await expect(apply).rejects.toThrow("host must contain only");
+    });
+  }
 });
diff --git a/registry/coder/modules/jupyterlab/main.tf b/registry/coder/modules/jupyterlab/main.tf
index f2b308608..6d190f831 100644
--- a/registry/coder/modules/jupyterlab/main.tf
+++ b/registry/coder/modules/jupyterlab/main.tf
@@ -41,6 +41,17 @@ variable "log_path" {
   default     = "/tmp/jupyterlab.log"
 }
 
+variable "host" {
+  description = "The host address that JupyterLab listens on."
+  type        = string
+  default     = "127.0.0.1"
+
+  validation {
+    condition     = can(regex("^[A-Za-z0-9](?:[A-Za-z0-9.-]*[A-Za-z0-9])?$", var.host))
+    error_message = "host must contain only letters, numbers, dots, and hyphens, and must start and end with a letter or number."
+  }
+}
+
 variable "port" {
   type        = number
   description = "The port to run jupyterlab on."
@@ -100,6 +111,7 @@ resource "coder_script" "jupyterlab" {
   icon         = "/icon/jupyter.svg"
   script = templatefile("${path.module}/run.sh", {
     LOG_PATH : var.log_path,
+    HOST : var.host,
     PORT : var.port
     BASE_URL : var.subdomain ? "" : "/@${data.coder_workspace_owner.me.name}/${data.coder_workspace.me.name}/apps/jupyterlab"
   })
diff --git a/registry/coder/modules/jupyterlab/main.tftest.hcl b/registry/coder/modules/jupyterlab/main.tftest.hcl
new file mode 100644
index 000000000..6fbc73647
--- /dev/null
+++ b/registry/coder/modules/jupyterlab/main.tftest.hcl
@@ -0,0 +1,84 @@
+run "secure_defaults" {
+  command = plan
+
+  variables {
+    agent_id = "test-agent-id"
+  }
+
+  assert {
+    condition     = var.host == "127.0.0.1"
+    error_message = "host must default to 127.0.0.1"
+  }
+
+  assert {
+    condition     = strcontains(coder_script.jupyterlab.script, "--ServerApp.ip='127.0.0.1'")
+    error_message = "the default script must bind JupyterLab to 127.0.0.1"
+  }
+
+  assert {
+    condition     = !strcontains(coder_script.jupyterlab.script, "0.0.0.0") && !strcontains(coder_script.jupyterlab.script, "--ServerApp.ip='*'")
+    error_message = "the default script must not bind JupyterLab to all interfaces"
+  }
+
+  assert {
+    condition     = coder_app.jupyterlab.url == "http://localhost:19999"
+    error_message = "the default Coder application URL must remain unchanged"
+  }
+
+  assert {
+    condition     = one(coder_app.jupyterlab.healthcheck).url == "http://localhost:19999/api"
+    error_message = "the JupyterLab healthcheck URL must remain unchanged"
+  }
+}
+
+run "path_mode_and_external_host" {
+  command = plan
+
+  variables {
+    agent_id  = "test-agent-id"
+    host      = "0.0.0.0"
+    subdomain = false
+  }
+
+  override_data {
+    target = data.coder_workspace.me
+    values = {
+      name = "example-workspace"
+    }
+  }
+
+  override_data {
+    target = data.coder_workspace_owner.me
+    values = {
+      name = "example-owner"
+    }
+  }
+
+  assert {
+    condition     = strcontains(coder_script.jupyterlab.script, "--ServerApp.ip='0.0.0.0'")
+    error_message = "the script must render an explicitly configured host"
+  }
+
+  assert {
+    condition     = strcontains(coder_script.jupyterlab.script, "--ServerApp.base_url=/@example-owner/example-workspace/apps/jupyterlab")
+    error_message = "the JupyterLab base URL must remain unchanged in path mode"
+  }
+
+  assert {
+    condition     = coder_app.jupyterlab.url == "http://localhost:19999/@example-owner/example-workspace/apps/jupyterlab"
+    error_message = "the JupyterLab application URL must remain unchanged in path mode"
+  }
+}
+
+run "unsafe_host_rejected" {
+  command = plan
+
+  variables {
+    agent_id = "test-agent-id"
+    host     = "127.0.0.1; touch /tmp/injected"
+  }
+
+  expect_failures = [
+    var.host,
+  ]
+}
diff --git a/registry/coder/modules/jupyterlab/run.sh b/registry/coder/modules/jupyterlab/run.sh
index 5edf35ef6..626a5dba1 100644
--- a/registry/coder/modules/jupyterlab/run.sh
+++ b/registry/coder/modules/jupyterlab/run.sh
@@ -49,10 +49,10 @@ fi
 
 printf "👷 Starting jupyterlab in background..."
 printf "check logs at ${LOG_PATH}"
-$JUPYTER --no-browser \
+"$JUPYTER" --no-browser \
   "$BASE_URL_FLAG" \
-  --ServerApp.ip='*' \
-  --ServerApp.port="${PORT}" \
+  --ServerApp.ip='${HOST}' \
+  --ServerApp.port='${PORT}' \
   --ServerApp.token='' \
   --ServerApp.password='' \
   > "${LOG_PATH}" 2>&1 &

From cdd85dc3daf9b09326ca16c263958509451b0be3 Mon Sep 17 00:00:00 2001
From: eddymarc <132223353+Edd88-pixel@users.noreply.github.com>
Date: Wed, 5 Aug 2026 17:35:10 +0100
Subject: [PATCH 2/4] fix(jupyter): address review feedback

---
 .../modules/jupyter-notebook/main.test.ts     | 18 ++++++++++++---
 .../coder/modules/jupyter-notebook/main.tf    |  4 ++--
 .../modules/jupyter-notebook/main.tftest.hcl  | 23 +++++++++++++++++--
 .../coder/modules/jupyter-notebook/run.sh     |  3 ++-
 .../coder/modules/jupyterlab/main.test.ts     |  3 +++
 registry/coder/modules/jupyterlab/main.tf     |  4 ++--
 .../coder/modules/jupyterlab/main.tftest.hcl  | 19 +++++++++++++++
 registry/coder/modules/jupyterlab/run.sh      |  1 +
 8 files changed, 65 insertions(+), 10 deletions(-)

diff --git a/registry/coder/modules/jupyter-notebook/main.test.ts b/registry/coder/modules/jupyter-notebook/main.test.ts
index 6c5f76e3d..d0028cedc 100644
--- a/registry/coder/modules/jupyter-notebook/main.test.ts
+++ b/registry/coder/modules/jupyter-notebook/main.test.ts
@@ -26,10 +26,11 @@ describe("jupyter-notebook", async () => {
     });
     const script = findResourceInstance(state, "coder_script").script;
 
-    expect(script).toContain("--NotebookApp.ip='127.0.0.1'");
+    expect(script).toContain("--ServerApp.ip='127.0.0.1'");
     expect(script).not.toContain("0.0.0.0");
     expect(script).not.toContain("--NotebookApp.ip='*'");
     expect(script).not.toContain("--ServerApp.ip='*'");
+    expect(script).toContain("--ServerApp.allow_remote_access=True");
 
     const id = await runContainer("alpine");
     try {
@@ -54,7 +55,8 @@ describe("jupyter-notebook", async () => {
       );
       expect(result.exitCode).toBe(0);
       const args = await readFileContainer(id, "/tmp/jupyter-args");
-      expect(args).toContain("--NotebookApp.ip=127.0.0.1");
+      expect(args).toContain("--ServerApp.ip=127.0.0.1");
+      expect(args).toContain("--ServerApp.allow_remote_access=True");
     } finally {
       await removeContainer(id);
     }
@@ -66,7 +68,17 @@ describe("jupyter-notebook", async () => {
       host: "0.0.0.0",
     });
     const script = findResourceInstance(state, "coder_script").script;
-    expect(script).toContain("--NotebookApp.ip='0.0.0.0'");
+    expect(script).toContain("--ServerApp.ip='0.0.0.0'");
+    expect(script).toContain("--ServerApp.allow_remote_access=True");
+  });
+
+  it("renders an IPv6 loopback host", async () => {
+    const state = await runTerraformApply(import.meta.dir, {
+      agent_id: "foo",
+      host: "::1",
+    });
+    const script = findResourceInstance(state, "coder_script").script;
+    expect(script).toContain("--ServerApp.ip='::1'");
   });
 
   for (const unsafeHost of [
diff --git a/registry/coder/modules/jupyter-notebook/main.tf b/registry/coder/modules/jupyter-notebook/main.tf
index d1843bd0d..b84b264aa 100644
--- a/registry/coder/modules/jupyter-notebook/main.tf
+++ b/registry/coder/modules/jupyter-notebook/main.tf
@@ -27,8 +27,8 @@ variable "host" {
   default     = "127.0.0.1"
 
   validation {
-    condition     = can(regex("^[A-Za-z0-9](?:[A-Za-z0-9.-]*[A-Za-z0-9])?$", var.host))
-    error_message = "host must contain only letters, numbers, dots, and hyphens, and must start and end with a letter or number."
+    condition     = can(regex("^[A-Za-z0-9:][A-Za-z0-9.:%_-]*$", var.host))
+    error_message = "host must contain only letters, numbers, colons, dots, percent signs, underscores, and hyphens."
   }
 }
 
diff --git a/registry/coder/modules/jupyter-notebook/main.tftest.hcl b/registry/coder/modules/jupyter-notebook/main.tftest.hcl
index ffb1a779f..8f683e889 100644
--- a/registry/coder/modules/jupyter-notebook/main.tftest.hcl
+++ b/registry/coder/modules/jupyter-notebook/main.tftest.hcl
@@ -11,10 +11,15 @@ run "secure_defaults" {
   }
 
   assert {
-    condition     = strcontains(coder_script.jupyter-notebook.script, "--NotebookApp.ip='127.0.0.1'")
+    condition     = strcontains(coder_script.jupyter-notebook.script, "--ServerApp.ip='127.0.0.1'")
     error_message = "the default script must bind Jupyter Notebook to 127.0.0.1"
   }
 
+  assert {
+    condition     = strcontains(coder_script.jupyter-notebook.script, "--ServerApp.allow_remote_access=True")
+    error_message = "the script must allow requests forwarded by the Coder application proxy"
+  }
+
   assert {
     condition     = !strcontains(coder_script.jupyter-notebook.script, "0.0.0.0") && !strcontains(coder_script.jupyter-notebook.script, "--NotebookApp.ip='*'") && !strcontains(coder_script.jupyter-notebook.script, "--ServerApp.ip='*'")
     error_message = "the default script must not bind Jupyter Notebook to all interfaces"
@@ -35,11 +40,25 @@ run "explicit_external_host" {
   }
 
   assert {
-    condition     = strcontains(coder_script.jupyter-notebook.script, "--NotebookApp.ip='0.0.0.0'")
+    condition     = strcontains(coder_script.jupyter-notebook.script, "--ServerApp.ip='0.0.0.0'")
     error_message = "the script must render an explicitly configured host"
   }
 }
 
+run "ipv6_loopback_host" {
+  command = plan
+
+  variables {
+    agent_id = "test-agent-id"
+    host     = "::1"
+  }
+
+  assert {
+    condition     = strcontains(coder_script.jupyter-notebook.script, "--ServerApp.ip='::1'")
+    error_message = "the script must render an IPv6 loopback host"
+  }
+}
+
 run "unsafe_host_rejected" {
   command = plan
 
diff --git a/registry/coder/modules/jupyter-notebook/run.sh b/registry/coder/modules/jupyter-notebook/run.sh
index 36559ec86..daf2abf73 100644
--- a/registry/coder/modules/jupyter-notebook/run.sh
+++ b/registry/coder/modules/jupyter-notebook/run.sh
@@ -41,8 +41,9 @@ fi
 echo "👷 Starting jupyter-notebook in background..."
 echo "check logs at ${LOG_PATH}"
 "$HOME/.local/bin/jupyter-notebook" \
-  --NotebookApp.ip='${HOST}' \
+  --ServerApp.ip='${HOST}' \
   --ServerApp.port='${PORT}' \
+  --ServerApp.allow_remote_access=True \
   --no-browser \
   --ServerApp.token='' \
   --ServerApp.password='' \
diff --git a/registry/coder/modules/jupyterlab/main.test.ts b/registry/coder/modules/jupyterlab/main.test.ts
index 721cfafb0..0b121fe00 100644
--- a/registry/coder/modules/jupyterlab/main.test.ts
+++ b/registry/coder/modules/jupyterlab/main.test.ts
@@ -184,6 +184,7 @@ describe("jupyterlab", async () => {
     expect(script).toContain("--ServerApp.ip='127.0.0.1'");
     expect(script).not.toContain("0.0.0.0");
     expect(script).not.toContain("--ServerApp.ip='*'");
+    expect(script).toContain("--ServerApp.allow_remote_access=True");
     expect(app.url).toBe("http://localhost:19999");
 
     const id = await runContainer("alpine");
@@ -198,6 +199,7 @@ describe("jupyterlab", async () => {
       expect(result.exitCode).toBe(0);
       const args = await readFileContainer(id, "/tmp/jupyter-args");
       expect(args).toContain("--ServerApp.ip=127.0.0.1");
+      expect(args).toContain("--ServerApp.allow_remote_access=True");
     } finally {
       await removeContainer(id);
     }
@@ -216,6 +218,7 @@ describe("jupyterlab", async () => {
     ).script;
 
     expect(script).toContain("--ServerApp.ip='0.0.0.0'");
+    expect(script).toContain("--ServerApp.allow_remote_access=True");
     expect(script).toContain("--ServerApp.base_url=/@");
     expect(script).toContain("/apps/jupyterlab");
   });
diff --git a/registry/coder/modules/jupyterlab/main.tf b/registry/coder/modules/jupyterlab/main.tf
index 6d190f831..e9fd2e00d 100644
--- a/registry/coder/modules/jupyterlab/main.tf
+++ b/registry/coder/modules/jupyterlab/main.tf
@@ -47,8 +47,8 @@ variable "host" {
   default     = "127.0.0.1"
 
   validation {
-    condition     = can(regex("^[A-Za-z0-9](?:[A-Za-z0-9.-]*[A-Za-z0-9])?$", var.host))
-    error_message = "host must contain only letters, numbers, dots, and hyphens, and must start and end with a letter or number."
+    condition     = can(regex("^[A-Za-z0-9:][A-Za-z0-9.:%_-]*$", var.host))
+    error_message = "host must contain only letters, numbers, colons, dots, percent signs, underscores, and hyphens."
   }
 }
 
diff --git a/registry/coder/modules/jupyterlab/main.tftest.hcl b/registry/coder/modules/jupyterlab/main.tftest.hcl
index 6fbc73647..eab375b04 100644
--- a/registry/coder/modules/jupyterlab/main.tftest.hcl
+++ b/registry/coder/modules/jupyterlab/main.tftest.hcl
@@ -15,6 +15,11 @@ run "secure_defaults" {
     error_message = "the default script must bind JupyterLab to 127.0.0.1"
   }
 
+  assert {
+    condition     = strcontains(coder_script.jupyterlab.script, "--ServerApp.allow_remote_access=True")
+    error_message = "the script must allow requests forwarded by the Coder application proxy"
+  }
+
   assert {
     condition     = !strcontains(coder_script.jupyterlab.script, "0.0.0.0") && !strcontains(coder_script.jupyterlab.script, "--ServerApp.ip='*'")
     error_message = "the default script must not bind JupyterLab to all interfaces"
@@ -70,6 +75,20 @@ run "path_mode_and_external_host" {
   }
 }
 
+run "ipv6_loopback_host" {
+  command = plan
+
+  variables {
+    agent_id = "test-agent-id"
+    host     = "::1"
+  }
+
+  assert {
+    condition     = strcontains(coder_script.jupyterlab.script, "--ServerApp.ip='::1'")
+    error_message = "the script must render an IPv6 loopback host"
+  }
+}
+
 run "unsafe_host_rejected" {
   command = plan
 
diff --git a/registry/coder/modules/jupyterlab/run.sh b/registry/coder/modules/jupyterlab/run.sh
index 626a5dba1..dbc0d0174 100644
--- a/registry/coder/modules/jupyterlab/run.sh
+++ b/registry/coder/modules/jupyterlab/run.sh
@@ -53,6 +53,7 @@ printf "check logs at ${LOG_PATH}"
   "$BASE_URL_FLAG" \
   --ServerApp.ip='${HOST}' \
   --ServerApp.port='${PORT}' \
+  --ServerApp.allow_remote_access=True \
   --ServerApp.token='' \
   --ServerApp.password='' \
   > "${LOG_PATH}" 2>&1 &

From 98d18563952af10d8e6e7abac9445c2403dd2386 Mon Sep 17 00:00:00 2001
From: eddymarc <132223353+Edd88-pixel@users.noreply.github.com>
Date: Wed, 5 Aug 2026 17:44:37 +0100
Subject: [PATCH 3/4] fix(jupyter): satisfy README validation

---
 registry/coder/modules/jupyter-notebook/README.md | 2 --
 registry/coder/modules/jupyterlab/README.md       | 2 --
 2 files changed, 4 deletions(-)

diff --git a/registry/coder/modules/jupyter-notebook/README.md b/registry/coder/modules/jupyter-notebook/README.md
index 7de146d4d..1d2089d72 100644
--- a/registry/coder/modules/jupyter-notebook/README.md
+++ b/registry/coder/modules/jupyter-notebook/README.md
@@ -15,8 +15,6 @@ A module that adds Jupyter Notebook in your Coder template.
 Jupyter Notebook listens on `127.0.0.1` by default so that unauthenticated
 traffic must pass through Coder's application proxy.
 
-## Usage
-
 ```tf
 module "jupyter-notebook" {
   count    = data.coder_workspace.me.start_count
diff --git a/registry/coder/modules/jupyterlab/README.md b/registry/coder/modules/jupyterlab/README.md
index bf0f77e19..7e39df91a 100644
--- a/registry/coder/modules/jupyterlab/README.md
+++ b/registry/coder/modules/jupyterlab/README.md
@@ -15,8 +15,6 @@ A module that adds JupyterLab in your Coder template.
 JupyterLab listens on `127.0.0.1` by default so that unauthenticated traffic
 must pass through Coder's application proxy.
 
-## Usage
-
 ```tf
 module "jupyterlab" {
   count    = data.coder_workspace.me.start_count

From 77db73e163573c9f2c9f691450eb48593fc9be10 Mon Sep 17 00:00:00 2001
From: eddymarc <132223353+Edd88-pixel@users.noreply.github.com>
Date: Thu, 6 Aug 2026 21:01:52 +0100
Subject: [PATCH 4/4] test(jupyter-notebook): remove outdated NotebookApp
 assertions

---
 registry/coder/modules/jupyter-notebook/main.test.ts    | 1 -
 registry/coder/modules/jupyter-notebook/main.tftest.hcl | 2 +-
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/registry/coder/modules/jupyter-notebook/main.test.ts b/registry/coder/modules/jupyter-notebook/main.test.ts
index d0028cedc..2bcb3ea25 100644
--- a/registry/coder/modules/jupyter-notebook/main.test.ts
+++ b/registry/coder/modules/jupyter-notebook/main.test.ts
@@ -28,7 +28,6 @@ describe("jupyter-notebook", async () => {
 
     expect(script).toContain("--ServerApp.ip='127.0.0.1'");
     expect(script).not.toContain("0.0.0.0");
-    expect(script).not.toContain("--NotebookApp.ip='*'");
     expect(script).not.toContain("--ServerApp.ip='*'");
     expect(script).toContain("--ServerApp.allow_remote_access=True");
 
diff --git a/registry/coder/modules/jupyter-notebook/main.tftest.hcl b/registry/coder/modules/jupyter-notebook/main.tftest.hcl
index 8f683e889..e6a351346 100644
--- a/registry/coder/modules/jupyter-notebook/main.tftest.hcl
+++ b/registry/coder/modules/jupyter-notebook/main.tftest.hcl
@@ -21,7 +21,7 @@ run "secure_defaults" {
   }
 
   assert {
-    condition     = !strcontains(coder_script.jupyter-notebook.script, "0.0.0.0") && !strcontains(coder_script.jupyter-notebook.script, "--NotebookApp.ip='*'") && !strcontains(coder_script.jupyter-notebook.script, "--ServerApp.ip='*'")
+    condition     = !strcontains(coder_script.jupyter-notebook.script, "0.0.0.0") && !strcontains(coder_script.jupyter-notebook.script, "--ServerApp.ip='*'")
     error_message = "the default script must not bind Jupyter Notebook to all interfaces"
   }