fix(gateway): default request_overrides to {} to avoid NoneType crash

[xiaoyuervae]

Summary

The gateway's per-turn agent reuse path assigns agent.request_overrides = turn_route.get(\"request_overrides\") at gateway/run.py:6974. dict.get() returns None when the key is absent, so request_overrides becomes None on the running agent. The next turn crashes inside _build_api_kwargs at:

fast_mode=self.request_overrides.get(\"speed\") == \"fast\",

with AttributeError: 'NoneType' object has no attribute 'get'.

The retry loop classifies this as a non-retryable API error and fast-fails into the fallback provider chain, so in practice every gateway turn silently falls back from the primary model to the first fallback (e.g. `openai-codex`) without ever issuing an HTTP request to the primary provider. The primary model is never actually tried.

Root cause

All 7 other call sites pass request_overrides through the AIAgent constructor, which normalizes the value via dict(request_overrides or {}) at run_agent.py:678. This direct attribute-assignment branch in gateway/run.py is the only path that bypassed that normalization.

Fix

One-line change — mirror the constructor's defensive default:

-            agent.request_overrides = turn_route.get(\"request_overrides\")
+            agent.request_overrides = turn_route.get(\"request_overrides\") or {}

Reproduction (before the fix)

1. Run hermes --profile <p> gateway with a primary provider that does not set `request_overrides` in its turn routing (e.g. a basic Discord DM flow through a custom provider).
2. Send a message. Gateway log shows:

   Fallback activated: <primary_model> → <fallback_model> (<fallback_provider>)
   

   with no HTTP request logged for the primary model and no `request_dump_*.json` written for the primary call.
3. Enabling DEBUG + a traceback in the error handler at `run_agent.py:8296` reveals:

   File \"run_agent.py\", line 5522, in _build_api_kwargs
       fast_mode=self.request_overrides.get(\"speed\") == \"fast\",
   AttributeError: 'NoneType' object has no attribute 'get'
   

After applying the fix, the primary model is invoked normally.

Test plan

• Manually verified on a `wechat-investment` profile with a custom Anthropic-Messages provider — primary model now handles Discord DMs correctly instead of fast-failing to the fallback.
• No existing tests covered the direct-attribute-assignment path; happy to add a regression test if maintainers would like one (simplest shape would assert that `_build_api_kwargs` works after `agent.request_overrides = None`).

[teknium1]

Thanks for the detailed write-up and repro steps, @xiaoyuervae! This crash was fixed on main the same day this PR was opened.

Automated hermes-sweeper review.

• The AttributeError: 'NoneType' object has no attribute 'get' in _build_api_kwargs was addressed by commit 0bea60351 (PR fix: handle NoneType request_overrides in fast_mode check #7350), which added the (self.request_overrides or {}).get("speed") guard in run_agent.py.
• That fix shipped in v2026.4.13 and is on current main at run_agent.py:7481.
• Your PR's approach (fixing the assignment in gateway/run.py:9964) is arguably cleaner since it addresses the root cause rather than the symptom. If you'd like to reopen with a revised scope, feel free — but the crash itself is resolved.