diff --git a/Dockerfile b/Dockerfile
index acb3ced1..839778a0 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -64,7 +64,8 @@ RUN curl -fsSL https://deb.nodesource.com/setup_22.x | bash - \
     && apt-get install -y "nodejs=${NODEJS_VERSION}" \
     && rm -rf /var/lib/apt/lists/* \
     && corepack enable \
-    && corepack prepare "yarn@${YARN_VERSION}" --activate
+    && corepack prepare "yarn@${YARN_VERSION}" --activate \
+    && npm i -g sfw
 
 ENV GO_VERSION=1.23.5
 
@@ -81,6 +82,7 @@ RUN echo "=== Installed versions ===" \
     && uv --version \
     && node --version \
     && yarn --version \
+    && sfw --version \
     && go version \
     && docker --version \
     && git --version \
diff --git a/agent/prompt.py b/agent/prompt.py
index 7726783f..3f38898c 100644
--- a/agent/prompt.py
+++ b/agent/prompt.py
@@ -244,8 +244,12 @@ If you encounter missing dependencies, install them using the appropriate packag
 
 - Use the correct package manager for the project; skip if installation fails.
 - Only install dependencies if the task requires it.
-- Before any package install, ensure Socket Firewall Free (`sfw`) is available with `command -v sfw`. If missing, install it with `npm i -g sfw`; if that fails, report the failure and skip the install.
-- Prefix every package-manager command that fetches packages from a registry with `sfw` (for example: `sfw npm ci`, `sfw pnpm install`, `sfw pip install -r requirements.txt`, `sfw uv pip install -e .`, `sfw poetry install`). Do not run bare install commands.
+- Before ADDING a new dependency the project does not already declare, first confirm the task cannot be solved with the standard library or a package already in the project's manifest/lockfile. Prefer reusing what is already there.
+- Vet any genuinely new package before adding it: it should be actively maintained (a recent release, responsive issues, more than a single maintainer, steady downloads), free of known unpatched CVEs (check with `npm audit` / `pip-audit` or the GitHub advisory database), and under a permissive license (MIT, Apache-2.0, BSD). Do not add abandoned, single-source, or unlicensed packages.
+- Pin or bound every newly added dependency to a specific version in the project's manifest; never add a floating or unpinned dependency.
+- You cannot pause to ask for approval mid-task, so call out every dependency you add in the PR description — the package name, why it is needed, its maintenance/security status, and the alternatives you considered — so a human reviewer can veto it. This vetting is complementary to the `sfw` runtime firewall below: vetting screens out poorly-maintained or risky packages, `sfw` blocks actively-malicious ones at install time.
+- Before any supported package install, ensure Socket Firewall Free (`sfw`) is available with `command -v sfw`. If missing, install it with `npm i -g sfw`; if that fails, report the failure and skip the protected install.
+- Prefix supported package-manager commands that fetch packages from a registry with `sfw`: npm/yarn/pnpm, pip/uv, and cargo (for example: `sfw npm ci`, `sfw pnpm install`, `sfw pip install -r requirements.txt`, `sfw uv pip install -e .`, `sfw cargo fetch`). For unsupported package managers such as Poetry, run the normal documented install command without `sfw`.
 - Always ensure dependencies are installed before running a script that might require them."""
 
 
diff --git a/agent/reviewer.py b/agent/reviewer.py
index b8ceafec..4f0d1fd3 100644
--- a/agent/reviewer.py
+++ b/agent/reviewer.py
@@ -109,10 +109,11 @@ Call `publish_review` once at the end.
 
 Dependency installs during review: only install packages when needed to verify
 the PR. Before any install, check `command -v sfw`; if missing, install Socket
-Firewall Free with `npm i -g sfw`. Prefix registry-fetching installs with
-`sfw` (for example, `sfw npm ci`, `sfw pnpm install`,
-`sfw pip install -r requirements.txt`, `sfw uv pip install -e .`).
-Do not run bare install commands.
+Firewall Free with `npm i -g sfw`. Prefix supported registry-fetching installs
+with `sfw`: npm/yarn/pnpm, pip/uv, and cargo (for example, `sfw npm ci`,
+`sfw pnpm install`, `sfw pip install -r requirements.txt`,
+`sfw uv pip install -e .`). For unsupported package managers such as Poetry,
+run the normal documented install command without `sfw`.
 
 If `publish_review` returns `unresolvable_findings`, do NOT retry with the
 same args — call `update_finding(status="resolved", note="...")` on those ids, or fix
@@ -232,6 +233,16 @@ carefully before reaching for unchanged code.
    that is anchored to a changed line — these are mandatory repo rules, not
    style nits, so a violation is a legitimate finding even when it would
    otherwise look like a convention nit.
+8. **New dependencies.** When the diff adds a dependency to a manifest or
+   lockfile (`package.json`, `pyproject.toml`, `requirements*.txt`,
+   `Cargo.toml`, `go.mod`, etc.), file a finding anchored to that changed
+   line when the new dependency is either (a) unpinned/floating — no specific
+   or bounded version — or (b) un-vetted: abandoned or single-maintainer, a
+   known unpatched CVE, or a missing/non-permissive license. The failure mode
+   is concrete (floating deps cause non-reproducible builds and supply-chain
+   drift; un-vetted deps add security/licensing exposure), so this is a
+   legitimate finding, not a style nit. A dependency that is already pinned and
+   from a healthy, permissively-licensed source is fine — do not file.
 
 Use `add_finding` to record each candidate. Every finding must include a
 concise generated `title` that names the failure mode in roughly 4-10 words;
diff --git a/tests/test_github_comment_prompts.py b/tests/test_github_comment_prompts.py
index 9a4ac8db..bb1195fe 100644
--- a/tests/test_github_comment_prompts.py
+++ b/tests/test_github_comment_prompts.py
@@ -49,7 +49,20 @@ def test_construct_system_prompt_includes_socket_firewall_dependency_guidance()
     assert "npm i -g sfw" in prompt
     assert "sfw npm ci" in prompt
     assert "sfw uv pip install -e ." in prompt
-    assert "Do not run bare install commands" in prompt
+    assert "sfw cargo fetch" in prompt
+    assert "unsupported package managers such as Poetry" in prompt
+    assert "normal documented install command without `sfw`" in prompt
+    assert "sfw poetry" not in prompt
+
+
+def test_construct_system_prompt_includes_dependency_vetting_guidance() -> None:
+    prompt = construct_system_prompt(working_dir="/workspace")
+
+    assert "Vet any genuinely new package before adding it" in prompt
+    assert "standard library or a package already in the project's manifest/lockfile" in prompt
+    assert "permissive license" in prompt
+    assert "never add a floating or unpinned dependency" in prompt
+    assert "call out every dependency you add in the PR description" in prompt
 
 
 def test_construct_system_prompt_identifies_own_repo() -> None:
diff --git a/tests/test_reviewer.py b/tests/test_reviewer.py
index d414cb66..79ecdb13 100644
--- a/tests/test_reviewer.py
+++ b/tests/test_reviewer.py
@@ -136,7 +136,23 @@ def test_reviewer_system_prompt_includes_socket_firewall_dependency_guidance() -
     assert "npm i -g sfw" in prompt
     assert "sfw npm ci" in prompt
     assert "sfw uv pip install -e ." in prompt
-    assert "Do not run bare install commands" in prompt
+    assert "supported registry-fetching installs" in prompt
+    assert "unsupported package managers such as Poetry" in prompt
+    assert "normal documented install command without `sfw`" in prompt
+    assert "sfw poetry" not in prompt
+
+
+def test_reviewer_system_prompt_includes_dependency_vetting_guidance() -> None:
+    prompt = reviewer._reviewer_system_prompt(
+        "/workspace/repo",
+        repo_owner="acme",
+        repo_name="repo",
+        pr_number=42,
+    )
+    assert "New dependencies." in prompt
+    assert "unpinned/floating" in prompt
+    assert "missing/non-permissive license" in prompt
+    assert "not a style nit" in prompt
 
 
 def test_finding_reply_context_wraps_reply_as_untrusted_data() -> None: