diff --git a/scripts/features/lib/classify.mjs b/scripts/features/lib/classify.mjs
new file mode 100644
index 0000000000..300222c511
--- /dev/null
+++ b/scripts/features/lib/classify.mjs
@@ -0,0 +1,93 @@
+/**
+ * Issue classification: quarantine filter + engagement override + skip rules.
+ */
+
+const HARDCODED_BOTS = new Set(["github-actions", "dependabot", "renovate", "claude", "copilot"]);
+
+export function isBot(user) {
+  if (!user) return false;
+  if (user.__typename === "Bot") return true;
+  const login = user.login || "";
+  if (login.endsWith("[bot]")) return true;
+  if (HARDCODED_BOTS.has(login)) return true;
+  return false;
+}
+
+function countThumbs(reactionGroups) {
+  if (!Array.isArray(reactionGroups)) return 0;
+  const g = reactionGroups.find((rg) => rg.content === "THUMBS_UP");
+  return g?.users?.totalCount ?? 0;
+}
+
+function uniqueCommenters(comments, authorLogin) {
+  if (!Array.isArray(comments)) return [];
+  const seen = new Set();
+  for (const c of comments) {
+    const u = c.author;
+    if (!u || !u.login) continue;
+    if (u.login === authorLogin) continue;
+    if (isBot(u)) continue;
+    seen.add(u.login);
+  }
+  return [...seen];
+}
+
+function openLinkedPrs(timelineItems) {
+  if (!Array.isArray(timelineItems)) return [];
+  const result = [];
+  for (const item of timelineItems) {
+    if (item.__typename !== "CrossReferencedEvent") continue;
+    const src = item.source;
+    if (!src || src.__typename !== "PullRequest") continue;
+    if (String(src.state).toLowerCase() !== "open") continue;
+    result.push({ number: src.number, state: "open" });
+  }
+  return result;
+}
+
+export function classifyIssue(issue, thresholds, now = new Date()) {
+  const assignees = issue.assignees ?? [];
+  if (assignees.length > 0) {
+    return {
+      bucket: "skip_assigned",
+      reason: "issue has assignees",
+      assignees: assignees.map((a) => a.login),
+    };
+  }
+
+  const linkedPrs = openLinkedPrs(issue.timelineItems);
+  if (linkedPrs.length > 0) {
+    return {
+      bucket: "skip_has_pr",
+      reason: "issue has open linked PR",
+      linkedPrs,
+    };
+  }
+
+  const createdAt = new Date(issue.createdAt).getTime();
+  let ageDays = Math.floor((now.getTime() - createdAt) / 86400_000);
+  if (ageDays < 0) ageDays = 0;
+
+  const thumbs = countThumbs(issue.reactionGroups);
+  const commenterLogins = uniqueCommenters(issue.comments, issue.author?.login);
+  const commenters = commenterLogins.length;
+
+  const meta = { ageDays, thumbs, commenters };
+
+  if (ageDays >= thresholds.quarantineDays) {
+    return { bucket: "absorb", reason: `age>=${thresholds.quarantineDays}`, ...meta };
+  }
+
+  const overrides = [];
+  if (thumbs >= thresholds.overrideThumbs) overrides.push("thumbs");
+  if (commenters >= thresholds.overrideCommenters) overrides.push("commenters");
+  if (overrides.length > 0) {
+    return { bucket: "absorb", reason: `override:${overrides.join("+")}`, ...meta };
+  }
+
+  return {
+    bucket: "dormant",
+    reason: `age<${thresholds.quarantineDays} && thumbs<${thresholds.overrideThumbs} && commenters<${thresholds.overrideCommenters}`,
+    ...meta,
+  };
+}
diff --git a/tests/unit/feature-triage/classify.test.mjs b/tests/unit/feature-triage/classify.test.mjs
new file mode 100644
index 0000000000..02c9cc0d11
--- /dev/null
+++ b/tests/unit/feature-triage/classify.test.mjs
@@ -0,0 +1,162 @@
+import { describe, it } from "node:test";
+import assert from "node:assert/strict";
+import { classifyIssue, isBot } from "../../../scripts/features/lib/classify.mjs";
+
+const DEFAULT_THRESHOLDS = {
+  quarantineDays: 14,
+  overrideThumbs: 5,
+  overrideCommenters: 3,
+};
+
+function makeIssue(overrides = {}) {
+  const now = new Date("2026-05-19T00:00:00Z");
+  return {
+    number: 1046,
+    title: "Test",
+    url: "https://github.com/x/y/issues/1046",
+    author: { login: "alice" },
+    createdAt: new Date(now.getTime() - 3 * 86400_000).toISOString(),
+    labels: [{ name: "enhancement" }],
+    assignees: [],
+    comments: [],
+    reactionGroups: [],
+    timelineItems: [],
+    ...overrides,
+  };
+}
+
+describe("isBot", () => {
+  it("detects [bot] suffix", () => {
+    assert.equal(isBot({ login: "dependabot[bot]" }), true);
+  });
+  it("detects hardcoded bot names", () => {
+    assert.equal(isBot({ login: "github-actions" }), true);
+    assert.equal(isBot({ login: "claude" }), true);
+    assert.equal(isBot({ login: "copilot" }), true);
+  });
+  it("detects Bot via __typename", () => {
+    assert.equal(isBot({ login: "anything", __typename: "Bot" }), true);
+  });
+  it("returns false for regular user", () => {
+    assert.equal(isBot({ login: "alice" }), false);
+  });
+});
+
+describe("classifyIssue", () => {
+  const now = new Date("2026-05-19T00:00:00Z");
+
+  it("3 days old, no engagement → dormant", () => {
+    const r = classifyIssue(makeIssue(), DEFAULT_THRESHOLDS, now);
+    assert.equal(r.bucket, "dormant");
+    assert.match(r.reason, /age<14/);
+  });
+
+  it("3 days old, 5 thumbs → absorb (override:thumbs)", () => {
+    const r = classifyIssue(
+      makeIssue({
+        reactionGroups: [{ content: "THUMBS_UP", users: { totalCount: 5 } }],
+      }),
+      DEFAULT_THRESHOLDS,
+      now
+    );
+    assert.equal(r.bucket, "absorb");
+    assert.match(r.reason, /override:thumbs/);
+    assert.equal(r.thumbs, 5);
+  });
+
+  it("3 days old, 3 unique non-bot non-author commenters → absorb (override:commenters)", () => {
+    const r = classifyIssue(
+      makeIssue({
+        comments: [
+          { author: { login: "bob" } },
+          { author: { login: "carol" } },
+          { author: { login: "dave" } },
+        ],
+      }),
+      DEFAULT_THRESHOLDS,
+      now
+    );
+    assert.equal(r.bucket, "absorb");
+    assert.match(r.reason, /override:commenters/);
+    assert.equal(r.commenters, 3);
+  });
+
+  it("3 days old, 4 commenters but 1 is bot → dormant", () => {
+    const r = classifyIssue(
+      makeIssue({
+        comments: [
+          { author: { login: "bob" } },
+          { author: { login: "carol" } },
+          { author: { login: "dependabot[bot]" } },
+        ],
+      }),
+      DEFAULT_THRESHOLDS,
+      now
+    );
+    assert.equal(r.bucket, "dormant");
+    assert.equal(r.commenters, 2);
+  });
+
+  it("3 days old, commenters include author → author excluded", () => {
+    const r = classifyIssue(
+      makeIssue({
+        comments: [
+          { author: { login: "alice" } },
+          { author: { login: "bob" } },
+          { author: { login: "carol" } },
+        ],
+      }),
+      DEFAULT_THRESHOLDS,
+      now
+    );
+    assert.equal(r.bucket, "dormant");
+    assert.equal(r.commenters, 2);
+  });
+
+  it("exactly 14 days old → absorb (age>=14)", () => {
+    const issue = makeIssue({
+      createdAt: new Date(now.getTime() - 14 * 86400_000).toISOString(),
+    });
+    const r = classifyIssue(issue, DEFAULT_THRESHOLDS, now);
+    assert.equal(r.bucket, "absorb");
+    assert.match(r.reason, /age>=14/);
+  });
+
+  it("20 days old with assignee → skip_assigned (precedence)", () => {
+    const r = classifyIssue(
+      makeIssue({
+        createdAt: new Date(now.getTime() - 20 * 86400_000).toISOString(),
+        assignees: [{ login: "alice" }],
+      }),
+      DEFAULT_THRESHOLDS,
+      now
+    );
+    assert.equal(r.bucket, "skip_assigned");
+  });
+
+  it("20 days old with open linked PR → skip_has_pr (precedence)", () => {
+    const r = classifyIssue(
+      makeIssue({
+        createdAt: new Date(now.getTime() - 20 * 86400_000).toISOString(),
+        timelineItems: [
+          {
+            __typename: "CrossReferencedEvent",
+            source: { __typename: "PullRequest", state: "OPEN", number: 2400 },
+          },
+        ],
+      }),
+      DEFAULT_THRESHOLDS,
+      now
+    );
+    assert.equal(r.bucket, "skip_has_pr");
+    assert.deepEqual(r.linkedPrs, [{ number: 2400, state: "open" }]);
+  });
+
+  it("custom thresholds (quarantineDays=7) respected", () => {
+    const issue = makeIssue({
+      createdAt: new Date(now.getTime() - 8 * 86400_000).toISOString(),
+    });
+    const r = classifyIssue(issue, { ...DEFAULT_THRESHOLDS, quarantineDays: 7 }, now);
+    assert.equal(r.bucket, "absorb");
+  });
+});