The two get_model_context_length() fallback callsites in api/streaming.py
(session save + SSE usage payload) were calling the resolver with only
model + base_url. When the agent's compressor reports 0 (fresh/cached/
transitioning agent), resolution fell through to the 256K DEFAULT_FALLBACK
even when users had set model.context_length: 1048576 in config.yaml.
For LCM users on 1M-context models, the wrong window cascaded into a
session-killing failure: auto-compression triggered at ~25% of the wrong
value, floods of compress requests, 429s, credential pool exhaustion,
fallback 429s, then 'API call failed after 3 retries'.
Reported by @AvidFuturist on Discord with deepseek-v4-flash. Reproduced 5x.
Both callsites now pass config_context_length, provider, and
custom_providers. The resolver consults these BEFORE probing, so the
config override wins. Both are wrapped in except TypeError blocks that
retry with the legacy 2-arg form for older hermes-agent builds whose
get_model_context_length signature pre-dates these kwargs.
Tests: 7 source-string regressions guarding both call shapes, the safe
config parse, the legacy fallback, and the per-profile config source.
Also bumped the line-distance assertion in test_pr1341 (the test
explicitly invites bumping when a new pre-save mutation block is added).
Closes#1896
Co-authored-by: Hermes Agent <agent@hermes.local>