diff --git a/CHANGELOG.d/0.78.0-adaptive-orchestration.md b/CHANGELOG.d/0.78.0-adaptive-orchestration.md
new file mode 100644
index 000000000..b51b63624
--- /dev/null
+++ b/CHANGELOG.d/0.78.0-adaptive-orchestration.md
@@ -0,0 +1,6 @@
+# 0.78.0 — Adaptive contextual-orchestrator defaults
+
+## Changed
+
+- Structured extraction, summarization, commitment, relationship-classification, and LLM-as-a-Judge consumers now request contextual-orchestrator `auto` mode, allowing the orchestration plane to meet the quality requirement and then minimize known execution cost.
+- Explicit checked `verify` paths remain unchanged.
diff --git a/docs/adr/0013-adaptive-contextual-orchestrator-default.md b/docs/adr/0013-adaptive-contextual-orchestrator-default.md
new file mode 100644
index 000000000..ee0402075
--- /dev/null
+++ b/docs/adr/0013-adaptive-contextual-orchestrator-default.md
@@ -0,0 +1,28 @@
+# ADR-0013: Adaptive contextual-orchestrator mode is the default
+
+- Status: Accepted
+- Date: 2026-08-16
+
+## Context
+
+LineageWeave used fixed single-worker `route` mode for structured extraction, summarization, commitment derivation, relationship classification, and post evaluation. That made each consumer choose the execution topology and prevented `contextual-orchestrator` from allocating deeper verification when task difficulty, uncertainty, or risk justified it.
+
+## Decision
+
+Ordinary LineageWeave LLM consumers request `mode="auto"`.
+
+The orchestration plane owns provider/model selection, test-time compute, workflow depth, verification, fallback, and known-price optimization. Quality sufficiency is the first constraint; cost is minimized among execution paths that satisfy it. Unpriced models are not treated as free.
+
+Explicit `verify` remains for the citation-bearing post-chat and lineage adjudication paths because those are deliberate checked-judgment contracts, not product defaults. Explicit route or conduct modes may be used only for documented ablation, incident response, or a bounded domain requirement.
+
+LineageWeave continues to own strict output parsing, evidence identifiers, IRT projection, and fail-closed domain validation.
+
+## Consequences
+
+A structured task may still be served by one model when the adaptive policy determines that it is sufficient. Harder requests may receive a deeper workflow without changing the LineageWeave API. Consumers must retain returned orchestration and usage evidence when the gateway exposes it.
+
+## References
+
+Omidvar, H., & Akhlaghi, V. (2026). *A communication-theoretic framework for LLM agents: Cost-aware adaptive reliability* [Preprint]. arXiv. https://doi.org/10.48550/arXiv.2605.09121
+
+Tang, Y., Cetin, E., Xu, J., Sun, Q., Nielsen, S., Richard, V., Goda, H., Tymchenko, I., Nguyen, N., Lee, H., Ashiga, M., Kotyan, S., Kuroki, S., & Clanuwat, T. (2026). *Sakana Fugu technical report* [Technical report]. arXiv. https://doi.org/10.48550/arXiv.2606.21228
diff --git a/lineageweave/commitment_extraction.py b/lineageweave/commitment_extraction.py
index 341eaa0c8..459376617 100644
--- a/lineageweave/commitment_extraction.py
+++ b/lineageweave/commitment_extraction.py
@@ -136,7 +136,7 @@ def parse_commitment_response(content: str) -> CustomerCommitment | None:
 
 
 class ContextualOrchestratorCommitmentExtractionClient:
-    """Calls ``POST {base_url}/v1/chat/completions`` with ``mode="route"``."""
+    """Calls ``POST {base_url}/v1/chat/completions`` with ``mode="auto"``."""
 
     available = True
 
@@ -156,7 +156,7 @@ def extract(self, post_title: str, post_body: str, reference_date: str) -> Custo
             f"{self._base_url}/v1/chat/completions",
             {
                 "messages": [{"role": "user", "content": prompt}],
-                "mode": "route",
+                "mode": "auto",
                 "reasoning_effort": self._reasoning_effort,
             },
             headers={"authorization": f"Bearer {self._api_key}"},
diff --git a/lineageweave/entity_relationship_classification.py b/lineageweave/entity_relationship_classification.py
index d1a2056ca..ad23e7d9a 100644
--- a/lineageweave/entity_relationship_classification.py
+++ b/lineageweave/entity_relationship_classification.py
@@ -157,7 +157,7 @@ def parse_classification_response(
 
 
 class ContextualOrchestratorEntityRelationshipClient:
-    """Calls ``POST {base_url}/v1/chat/completions`` with ``mode="route"``."""
+    """Calls ``POST {base_url}/v1/chat/completions`` with ``mode="auto"``."""
 
     available = True
 
@@ -183,7 +183,7 @@ def classify(
             f"{self._base_url}/v1/chat/completions",
             {
                 "messages": [{"role": "user", "content": prompt}],
-                "mode": "route",
+                "mode": "auto",
                 "reasoning_effort": self._reasoning_effort,
             },
             headers={"authorization": f"Bearer {self._api_key}"},
diff --git a/lineageweave/keyman_extraction.py b/lineageweave/keyman_extraction.py
index d7e8de952..5775c0f20 100644
--- a/lineageweave/keyman_extraction.py
+++ b/lineageweave/keyman_extraction.py
@@ -11,10 +11,10 @@
 contextual-orchestrator instance -- never a raw LLM API directly, per
 AGENTS.md -- because Keyman identification is a structured-extraction task
 that benefits from the orchestrator's reasoning-effort allocation, not a
-single confidence number, so it uses ``mode="route"`` (one worker call) at
-a ``"medium"`` reasoning effort by default rather than ``verify``'s
-worker-plus-checker pattern, which is reserved for adjudication's binary
-judgment calls.
+single confidence number, so it uses ``mode="auto"`` and lets the orchestration plane allocate
+quality-sufficient test-time compute before minimizing known cost. Explicit
+``verify`` remains reserved for adjudication's checked binary-judgment
+contract.
 """
 
 from __future__ import annotations
@@ -133,7 +133,7 @@ def parse_keyman_response(content: str) -> list[PersonMention]:
 
 
 class ContextualOrchestratorKeymanExtractionClient:
-    """Calls ``POST {base_url}/v1/chat/completions`` with ``mode="route"``."""
+    """Calls ``POST {base_url}/v1/chat/completions`` with ``mode="auto"``."""
 
     available = True
 
@@ -151,7 +151,7 @@ def extract(self, post_title: str, post_body: str) -> list[PersonMention]:
             f"{self._base_url}/v1/chat/completions",
             {
                 "messages": [{"role": "user", "content": prompt}],
-                "mode": "route",
+                "mode": "auto",
                 "reasoning_effort": self._reasoning_effort,
             },
             headers={"authorization": f"Bearer {self._api_key}"},
diff --git a/lineageweave/post_evaluation.py b/lineageweave/post_evaluation.py
index 09ce21fd2..2d3be6291 100644
--- a/lineageweave/post_evaluation.py
+++ b/lineageweave/post_evaluation.py
@@ -85,7 +85,7 @@ def __init__(self, base_url: str, api_key: str, *, timeout: float = 60.0) -> Non
         self._api_key = api_key
         self._timeout = timeout
 
-    def complete(self, messages: list[dict[str, Any]], mode: str = "route") -> dict[str, Any]:
+    def complete(self, messages: list[dict[str, Any]], mode: str = "auto") -> dict[str, Any]:
         body = post_json(
             f"{self._base_url}/v1/chat/completions",
             {"messages": messages, "mode": mode, "reasoning_effort": "medium"},
@@ -107,7 +107,7 @@ class ContextualOrchestratorPostEvaluationClient:
     def __init__(self, base_url: str, api_key: str, *, timeout: float = 60.0) -> None:
         self._judge = ContextualOrchestratorJudge(
             _OrchestratorCompleteAdapter(base_url, api_key, timeout=timeout),
-            mode="route",
+            mode="auto",
         )
 
     def evaluate(self, post_title: str, post_body: str) -> LLMJudgeResult:
diff --git a/lineageweave/post_summary.py b/lineageweave/post_summary.py
index 4974268c2..eac051fda 100644
--- a/lineageweave/post_summary.py
+++ b/lineageweave/post_summary.py
@@ -152,7 +152,7 @@ def parse_summary_response(content: str) -> PostSummary | None:
 
 
 class ContextualOrchestratorPostSummaryClient:
-    """Calls ``POST {base_url}/v1/chat/completions`` with ``mode="route"``."""
+    """Calls ``POST {base_url}/v1/chat/completions`` with ``mode="auto"``."""
 
     available = True
 
@@ -170,7 +170,7 @@ def summarize(self, post_title: str, post_body: str) -> PostSummary:
             f"{self._base_url}/v1/chat/completions",
             {
                 "messages": [{"role": "user", "content": prompt}],
-                "mode": "route",
+                "mode": "auto",
                 "reasoning_effort": self._reasoning_effort,
             },
             headers={"authorization": f"Bearer {self._api_key}"},
diff --git a/tests/test_adaptive_orchestration_defaults.py b/tests/test_adaptive_orchestration_defaults.py
new file mode 100644
index 000000000..aa84ad30a
--- /dev/null
+++ b/tests/test_adaptive_orchestration_defaults.py
@@ -0,0 +1,131 @@
+"""Adaptive contextual-orchestrator defaults remain explicit at every consumer boundary."""
+
+from __future__ import annotations
+
+import json
+
+import pytest
+
+from lineageweave.commitment_extraction import (
+    ContextualOrchestratorCommitmentExtractionClient,
+)
+from lineageweave.entity_relationship_classification import (
+    ContextualOrchestratorEntityRelationshipClient,
+)
+from lineageweave.keyman_extraction import (
+    ContextualOrchestratorKeymanExtractionClient,
+)
+from lineageweave.post_evaluation import ContextualOrchestratorPostEvaluationClient
+from lineageweave.post_summary import ContextualOrchestratorPostSummaryClient
+
+
+@pytest.mark.parametrize(
+    ("module_name", "client_factory", "invoke", "content"),
+    [
+        (
+            "lineageweave.post_summary",
+            lambda: ContextualOrchestratorPostSummaryClient("https://orchestrator.test", "token"),
+            lambda client: client.summarize("Title", "Body"),
+            json.dumps(
+                {
+                    "korean_summary": "요약",
+                    "key_events": [],
+                    "roles_and_responsibilities": [],
+                }
+            ),
+        ),
+        (
+            "lineageweave.keyman_extraction",
+            lambda: ContextualOrchestratorKeymanExtractionClient(
+                "https://orchestrator.test", "token"
+            ),
+            lambda client: client.extract("Title", "Body"),
+            "[]",
+        ),
+        (
+            "lineageweave.commitment_extraction",
+            lambda: ContextualOrchestratorCommitmentExtractionClient(
+                "https://orchestrator.test", "token"
+            ),
+            lambda client: client.extract("Title", "Body", "2026-08-16"),
+            json.dumps(
+                {
+                    "has_commitment": False,
+                    "commitment_summary": None,
+                    "due_date": None,
+                }
+            ),
+        ),
+        (
+            "lineageweave.entity_relationship_classification",
+            lambda: ContextualOrchestratorEntityRelationshipClient(
+                "https://orchestrator.test", "token"
+            ),
+            lambda client: client.classify("Title", "Body", ["Example Corp"]),
+            json.dumps(
+                [
+                    {
+                        "organization_name": "Example Corp",
+                        "relationship_type_code": "rel_voc",
+                    }
+                ]
+            ),
+        ),
+    ],
+)
+def test_structured_consumers_request_auto_mode(
+    monkeypatch, module_name, client_factory, invoke, content
+) -> None:
+    observed: dict[str, object] = {}
+
+    def fake_post_json(url, payload, *, headers, timeout):
+        observed["url"] = url
+        observed["payload"] = payload
+        observed["headers"] = headers
+        observed["timeout"] = timeout
+        return {"choices": [{"message": {"content": content}}]}
+
+    module = __import__(module_name, fromlist=["post_json"])
+    monkeypatch.setattr(module, "post_json", fake_post_json)
+
+    invoke(client_factory())
+
+    assert observed["payload"]["mode"] == "auto"
+
+
+def test_post_evaluation_judge_defaults_to_auto(monkeypatch) -> None:
+    observed: dict[str, object] = {}
+
+    def fake_post_json(url, payload, *, headers, timeout):
+        observed["payload"] = payload
+        return {
+            "choices": [
+                {
+                    "message": {
+                        "content": json.dumps(
+                            {
+                                "score": 1.0,
+                                "accepted": True,
+                                "rationale": "Evidence supports each criterion.",
+                                "criterion_categories": {
+                                    "general_sentiment_negative": 4,
+                                    "general_sentiment_positive": 4,
+                                    "sales_lead_specificity": 4,
+                                },
+                            }
+                        )
+                    }
+                }
+            ]
+        }
+
+    import lineageweave.post_evaluation as module
+
+    monkeypatch.setattr(module, "post_json", fake_post_json)
+    client = ContextualOrchestratorPostEvaluationClient(
+        "https://orchestrator.test", "token"
+    )
+
+    client.evaluate("Title", "Body")
+
+    assert observed["payload"]["mode"] == "auto"