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Bedrock Converse: skip sampling params for Opus 4.7/4.8

NousResearch/hermes-agent · cluster 36151 · agent

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Nothing open on GitHub. Fix merged in #45675. Check it covers your case.

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0open issues
0open PRs
6items grouped
Known?
Yes. 6 related items grouped here, 1 issue already closed.
Fix event
A fix was merged to main in PR #45675. Check it covers your case. No release data is tracked.
Tracker
The maintainers' tracker marks this resolved, deciding PR #45675. That is separate from the fix event.
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Nothing open on GitHub.

Multiple fixes and a bug report addressing that temperature and top_p must be omitted for Claude Opus 4.7 and 4.8 on the AWS Bedrock Converse API, which rejects those parameters with a 400 error.

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No open issues.

Open PRs0

No open pull requests.

Fixes on record

Merged to main. A stamp counts the issues a fix is linked to.

  • #45675 fix(bedrock): omit sampling params for restricted Claude models

    merged to main

    files: agent/bedrock_adapter.py, tests/agent/test_bedrock_adapter.py

    Show the diff
    • agent/bedrock_adapter.py
      @@ -935,11 +935,14 @@ def build_converse_kwargs(
     if system_prompt:
         kwargs["system"] = system_prompt
 
-    if temperature is not None:
-        kwargs["inferenceConfig"]["temperature"] = temperature
+    from agent.anthropic_adapter import _forbids_sampling_params
 
-    if top_p is not None:
-        kwargs["inferenceConfig"]["topP"] = top_p
+    if not _forbids_sampling_params(model):
+        if temperature is not None:
+            kwargs["inferenceConfig"]["temperature"] = temperature
+
+        if top_p is not None:
+            kwargs["inferenceConfig"]["topP"] = top_p
 
     if stop_sequences:
         kwargs["inferenceConfig"]["stopSequences"] = stop_sequences
    • tests/agent/test_bedrock_adapter.py
      @@ -605,6 +605,74 @@ def test_includes_temperature_and_top_p(self):
         assert kwargs["inferenceConfig"]["temperature"] == 0.7
         assert kwargs["inferenceConfig"]["topP"] == 0.9
 
+    def test_omits_sampling_params_for_bedrock_opus_4_7(self):
+        from agent.bedrock_adapter import build_converse_kwargs
+
+        for model_id in (
+            "anthropic.claude-opus-4-7-20260101-v1:0",
+            "us.anthropic.claude-opus-4-7",
+        ):
+            kwargs = build_converse_kwargs(
+                model=model_id,
+                messages=[{"role": "user", "content": "Hi"}],
+                temperature=0.7,
+                top_p=0.9,
+            )
+
+            assert "temperature" not in kwargs["inferenceConfig"]
+            assert "topP" not in kwargs["inferenceConfig"]
+
+    def test_omits_sampling_params_for_bedrock_opus_4_8_variants(self):
+        from agent.bedrock_adapter import build_converse_kwargs
+
+        for model_id in (
+            "anthropic.claude-opus-4-8-20270101-v1:0",
+            "us.anthropic.claude-opus-4-8",
+            "anthropic.claude-opus-4.8",
+        ):
+            kwargs = build_converse_kwargs(
+                model=model_id,
+                messages=[{"role": "user", "content": "Hi"}],
+                temperature=0.5,
+                top_p=0.95,
+            )
+
+            assert "temperature" not in kwargs["inferenceConfig"]
+            assert "topP" not in kwargs["inferenceConfig"]
+
+    def test_keeps_sampling_params_for_bedrock_non_restricted_models(self):
+        from agent.bedrock_adapter import build_converse_kwargs
+
+        for model_id in (
+            "anthropic.claude-sonnet-4-6-20250514-v1:0",
+            "anthropic.claude-haiku-4-5",
+            "test-model",
+        ):
+            kwargs = build_converse_kwargs(
+                model=model_id,
+                messages=[{"role": "user", "content": "Hi"}],
+                temperature=0.7,
+                top_p=0.9,
+            )
+
+            assert kwargs["inferenceConfig"].get("temperature") == 0.7
+            assert kwargs["inferenceConfig"].get("topP") == 0.9
+
+    def test_bedrock_opus_strips_sampling_params_but_keeps_stop_sequences(self):
+        from agent.bedrock_adapter import build_converse_kwargs
+
+        kwargs = build_converse_kwargs(
+            model="us.anthropic.claude-opus-4-8",
+            messages=[{"role": "user", "content": "Hi"}],
+            temperature=0.7,
+            top_p=0.9,
+            stop_sequences=["END"],
+        )
+
+        assert "temperature" not in kwargs["inferenceConfig"]
+        assert "topP" not in kwargs["inferenceConfig"]
+        assert kwargs["inferenceConfig"]["stopSequences"] == ["END"]
+
     def test_includes_guardrail_config(self):
         from agent.bedrock_adapter import build_converse_kwargs
         guardrail = {

4 PRs closed without merging

From the close comments: done elsewhere 2 · merged via another change 2

  • #36175 fix(bedrock): guard temperature/top_p for Opus 4.7/4.8 on Converse · done elsewhere → 957a8ff, #45675
  • #36257 fix(bedrock): guard temperature/top_p for Opus 4.7/4.8 on Converse API (#36151) · merged via another change → #45675, #38717
  • #37912 fix(bedrock): skip temperature/top_p for Opus 4.7+ on Converse API · done elsewhere → 957a8ff, #36151, #45675
  • #38717 fix(agent): skip temperature/topP for Opus 4.7/4.8 on Bedrock (#36151) · merged via another change → 957a8ff, #45675, #36257
Closed issues · 1
  • Closed#36151bedrock_adapter: Opus 4.8 (and 4.7) on Bedrock Converse 400s with "temperature is deprecated" — _forbids_sampling_params guard never applied to Bedrock path
How this cluster was grouped
  • Link evidence (structural links throughout): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.
  • Pairwise link density 0.33: the share of item pairs that carry a link, counting a structural link in full and a relevance-only link at 0.36. 1.00 means every pair is linked.

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Subsystem
agent
Merged PRs
#45675
Closed issues
1
Attempts
4 PRs closed without merging
Fix link checked
13 Jun 2026

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