diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f89857ed..ebe88a6f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -11,6 +11,18 @@ env:
   RUSTFLAGS: -Dwarnings
 
 jobs:
+  versions:
+    name: Version drift
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+      - name: Check version drift
+        run: ./scripts/release/check-versions.sh
+
   lint:
     name: Lint
     runs-on: ubuntu-latest
diff --git a/docs/RELEASE_RUNBOOK.md b/docs/RELEASE_RUNBOOK.md
index 2c8e76a8..df678e96 100644
--- a/docs/RELEASE_RUNBOOK.md
+++ b/docs/RELEASE_RUNBOOK.md
@@ -42,6 +42,7 @@ Current packaging note:
 Run these from the repository root before cutting a tag:
 
 ```bash
+./scripts/release/check-versions.sh   # version drift between workspace, npm, lockfile
 cargo fmt --all -- --check
 cargo check --workspace --all-targets --locked
 cargo clippy --workspace --all-targets --all-features --locked -- -D warnings
@@ -50,6 +51,11 @@ cargo publish --dry-run --locked --allow-dirty -p deepseek-tui
 ./scripts/release/publish-crates.sh dry-run
 ```
 
+`check-versions.sh` also runs in CI on every push/PR (the `versions` job in
+`.github/workflows/ci.yml`), so drift between `Cargo.toml`, the per-crate
+manifests, `npm/deepseek-tui/package.json`, and `Cargo.lock` is caught before
+release time rather than at it.
+
 `publish-crates.sh dry-run` performs a full `cargo publish --dry-run` for crates
 without unpublished workspace dependencies and a packaging preflight for dependent
 workspace crates. That avoids false negatives from crates.io not yet containing the
diff --git a/scripts/release/check-versions.sh b/scripts/release/check-versions.sh
new file mode 100755
index 00000000..cab67183
--- /dev/null
+++ b/scripts/release/check-versions.sh
@@ -0,0 +1,44 @@
+#!/usr/bin/env bash
+# Fails CI if version state is inconsistent across the workspace, npm
+# wrapper, and Cargo.lock. Run on every push/PR so silent drift can't ship.
+#
+# Checks performed:
+#   1. No `crates/*/Cargo.toml` carries a literal `version = "x.y.z"`; every
+#      crate must inherit `version.workspace = true`.
+#   2. `npm/deepseek-tui/package.json` `version` matches the workspace
+#      `version` in the root `Cargo.toml`.
+#   3. `Cargo.lock` is in sync with the manifests (`cargo metadata --locked`
+#      fails if not).
+set -euo pipefail
+
+cd "$(dirname "$0")/../.."
+
+fail=0
+
+# 1) Literal versions in crate manifests.
+literals="$(grep -nE '^version = "' crates/*/Cargo.toml || true)"
+if [[ -n "${literals}" ]]; then
+  echo "::error::Crate manifests must use 'version.workspace = true', not literal versions:" >&2
+  echo "${literals}" >&2
+  fail=1
+fi
+
+# 2) Workspace ↔ npm package.json.
+workspace_version="$(grep -E '^version = "' Cargo.toml | head -n1 | sed -E 's/^version = "([^"]+)".*/\1/')"
+npm_version="$(node -p "require('./npm/deepseek-tui/package.json').version")"
+if [[ "${workspace_version}" != "${npm_version}" ]]; then
+  echo "::error::npm/deepseek-tui/package.json version (${npm_version}) does not match workspace Cargo.toml (${workspace_version})." >&2
+  fail=1
+fi
+
+# 3) Cargo.lock in sync.
+if ! cargo metadata --locked --format-version 1 --no-deps >/dev/null 2>&1; then
+  echo "::error::Cargo.lock is out of sync with the manifests. Run 'cargo update -p deepseek-tui' or 'cargo build' and commit the result." >&2
+  fail=1
+fi
+
+if [[ "${fail}" -eq 0 ]]; then
+  echo "Version state OK: workspace=${workspace_version}, npm=${npm_version}, lockfile in sync."
+fi
+
+exit "${fail}"