diff --git a/atlasbot/engine/answerer.py b/atlasbot/engine/answerer.py
index 0cef0b9..2205043 100644
--- a/atlasbot/engine/answerer.py
+++ b/atlasbot/engine/answerer.py
@@ -312,8 +312,23 @@ class AnswerEngine:
                 if observer:
                     observer("retrieve", "scoring chunks")
                 chunks = _chunk_lines(summary_lines, plan.chunk_lines)
+                metric_keys: list[str] = []
+                must_chunk_ids: list[str] = []
+                if (classify.get("question_type") in {"metric", "diagnostic"} or force_metric) and summary_lines:
+                    metric_ctx = {
+                        "question": normalized,
+                        "sub_questions": sub_questions,
+                        "keywords": keywords,
+                        "summary_lines": summary_lines,
+                    }
+                    metric_keys, must_chunk_ids = await _select_metric_chunks(
+                        call_llm,
+                        metric_ctx,
+                        chunks,
+                        plan,
+                    )
                 scored = await _score_chunks(call_llm, chunks, normalized, sub_questions, plan)
-                selected = _select_chunks(chunks, scored, plan, keyword_tokens)
+                selected = _select_chunks(chunks, scored, plan, keyword_tokens, must_chunk_ids)
                 fact_candidates = _collect_fact_candidates(selected, limit=plan.max_subquestions * 12)
                 key_facts = await _select_fact_lines(
                     call_llm,
@@ -422,6 +437,8 @@ class AnswerEngine:
                         {
                             "selected_ids": [item["id"] for item in selected],
                             "top_scored": scored_preview,
+                            "metric_keys": metric_keys,
+                            "forced_chunks": must_chunk_ids,
                         },
                     )
                 facts_used = list(dict.fromkeys(key_facts)) if key_facts else list(dict.fromkeys(metric_facts))
@@ -1157,6 +1174,7 @@ def _select_chunks(
     scores: dict[str, float],
     plan: ModePlan,
     keywords: list[str] | None = None,
+    must_ids: list[str] | None = None,
 ) -> list[dict[str, Any]]:
     if not chunks:
         return []
@@ -1164,6 +1182,14 @@ def _select_chunks(
     selected: list[dict[str, Any]] = []
     head = chunks[0]
     selected.append(head)
+    id_map = {item["id"]: item for item in chunks}
+    if must_ids:
+        for cid in must_ids:
+            item = id_map.get(cid)
+            if item and item not in selected:
+                selected.append(item)
+                if len(selected) >= plan.chunk_top:
+                    return selected
 
     for item in _keyword_hits(ranked, head, keywords):
         if len(selected) >= plan.chunk_top:
@@ -1218,6 +1244,89 @@ def _summary_lines(snapshot: dict[str, Any] | None) -> list[str]:
     return [line for line in text.splitlines() if line.strip()]
 
 
+async def _select_metric_chunks(
+    call_llm: Callable[..., Awaitable[str]],
+    ctx: dict[str, Any],
+    chunks: list[dict[str, Any]],
+    plan: ModePlan,
+) -> tuple[list[str], list[str]]:
+    summary_lines = ctx.get("summary_lines") if isinstance(ctx, dict) else None
+    if not isinstance(summary_lines, list):
+        return [], []
+    keys = _extract_metric_keys(summary_lines)
+    if not keys or not chunks:
+        return [], []
+    max_keys = max(4, plan.max_subquestions * 2)
+    prompt = prompts.METRIC_KEYS_PROMPT.format(available="\n".join(keys), max_keys=max_keys)
+    question = ctx.get("question") if isinstance(ctx, dict) else ""
+    sub_questions = ctx.get("sub_questions") if isinstance(ctx, dict) else []
+    keywords = ctx.get("keywords") if isinstance(ctx, dict) else []
+    raw = await call_llm(
+        prompts.METRIC_KEYS_SYSTEM,
+        prompt + "\nQuestion: " + str(question) + "\nSubQuestions:\n" + "\n".join([str(item) for item in sub_questions]),
+        context="Keywords:\n" + ", ".join([str(item) for item in keywords if item]),
+        model=plan.fast_model,
+        tag="metric_keys",
+    )
+    selected = _parse_key_list(raw, keys, max_keys)
+    if not selected:
+        return [], []
+    ids = _chunk_ids_for_keys(chunks, selected)
+    return selected, ids
+
+
+def _extract_metric_keys(lines: list[str]) -> list[str]:
+    keys: list[str] = []
+    for line in lines:
+        if ":" not in line:
+            continue
+        key = line.split(":", 1)[0].strip()
+        if not key or " " in key:
+            continue
+        if key not in keys:
+            keys.append(key)
+    return keys
+
+
+def _parse_key_list(raw: str, allowed: list[str], max_keys: int) -> list[str]:
+    parsed = _parse_json_block(raw, fallback={})
+    if isinstance(parsed, list):
+        items = parsed
+    else:
+        items = parsed.get("keys") if isinstance(parsed, dict) else []
+    if not isinstance(items, list):
+        return []
+    allowed_set = set(allowed)
+    out: list[str] = []
+    for item in items:
+        if not isinstance(item, str):
+            continue
+        if item in allowed_set and item not in out:
+            out.append(item)
+        if len(out) >= max_keys:
+            break
+    return out
+
+
+def _chunk_ids_for_keys(chunks: list[dict[str, Any]], keys: list[str]) -> list[str]:
+    if not keys:
+        return []
+    ids: list[str] = []
+    key_set = {f"{key}:" for key in keys}
+    for chunk in chunks:
+        text = str(chunk.get("text") or "")
+        if not text:
+            continue
+        for line in text.splitlines():
+            for key in key_set:
+                if line.startswith(key):
+                    cid = chunk.get("id")
+                    if cid and cid not in ids:
+                        ids.append(cid)
+                    break
+    return ids
+
+
 def _merge_fact_lines(primary: list[str], fallback: list[str]) -> list[str]:
     seen = set()
     merged: list[str] = []
diff --git a/atlasbot/llm/prompts.py b/atlasbot/llm/prompts.py
index 4f24e2f..d3accf1 100644
--- a/atlasbot/llm/prompts.py
+++ b/atlasbot/llm/prompts.py
@@ -69,6 +69,20 @@ METRIC_PREFIX_PROMPT = (
     "Only use values from AvailablePrefixes."
 )
 
+METRIC_KEYS_SYSTEM = (
+    CLUSTER_SYSTEM
+    + " Select the metric keys required to answer the question. "
+    + "Return JSON only."
+)
+
+METRIC_KEYS_PROMPT = (
+    "AvailableKeys:\n{available}\n\n"
+    "Return JSON with field: keys (list). "
+    "Choose only keys needed to answer the question. "
+    "If none apply, return an empty list. "
+    "Limit to at most {max_keys} keys."
+)
+
 TOOL_SYSTEM = (
     CLUSTER_SYSTEM
     + " Suggest a safe, read-only command that could refine the answer. "