fix: retire context-1m-2025-08-07 beta header for Sonnet 4.0 and 4.5 - #51
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Ken Chau (kenotron-ms) wants to merge 2 commits into
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fix: retire context-1m-2025-08-07 beta header for Sonnet 4.0 and 4.5#51Ken Chau (kenotron-ms) wants to merge 2 commits into
Ken Chau (kenotron-ms) wants to merge 2 commits into
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Retiring the `context-1m-2025-08-07` beta header for Sonnet 4.0 and 4.5: - Header was deprecated by Anthropic on 2026-04-30 - Those models now hard-cap at 200k context regardless - Updated `_should_add_context_1m_beta` to only send header for Sonnet 4.6+ and unknown versions (forward-compat) - Removed `claude-3-haiku-20240307` from `_DEPRECATED_MODELS` dict (retired 2026-04-19, no longer needs a warning) - Added clarifying comment confirming interleaved-thinking guard correctly prevents deprecated header on Opus 4.6+ adaptive - Updated 6 tests in test_opus_47.py and test_fallback.py to reflect new behavior - All 410 tests pass Fixes #42 Generated with Amplifier Co-Authored-By: Amplifier <240397093+microsoft-amplifier@users.noreply.github.com>
- Added enable_1m_context startup check in __init__ that fires for Sonnet/Opus <4.6 whose 1M beta was retired 2026-04-30. Warns user sessions are capped at 200k and suggests migration to 4.6+ - Moved Haiku 3 tombstone comment out of dict literal body to standalone comment above _DEPRECATED_MODELS for clarity - Added 8 new tests in TestEnable1mContextRetirementWarning covering: - warning fires for Sonnet 4.5 and Opus 4.5 - no warning for Sonnet/Opus 4.6+ - warning suppressed when enable_1m_context=False - no false positives for unknown versions Fixes microsoft-amplifier/amplifier-shared#42 Generated with Amplifier Co-Authored-By: Amplifier <240397093+microsoft-amplifier@users.noreply.github.com>
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Summary
Closes / related to: microsoft-amplifier/amplifier-shared#42
Anthropic retired the
context-1m-2025-08-07beta header for Sonnet 4.0 (claude-sonnet-4-20250514) and Sonnet 4.5 on 2026-04-30. The header now has no effect on those models; any context exceeding the 200k standard limit returns a400 INVALID_ARGUMENT. Previously, the provider was sending this retired header for all Sonnet ≥ 4.0.Changes
amplifier_module_provider_anthropic/__init__.py_should_add_context_1m_beta: Scoped the Sonnet branch from>= (4, 0)→>= (4, 6). Header now only sent for Sonnet 4.6+ (where 1M is GA) and unknown versions (forward-compat). Opus gate was already correctly at 4.6+._DEPRECATED_MODELS: Removedclaude-3-haiku-20240307(retirement date2026-04-19is past; the model is fully retired)._should_add_interleaved_beta: Added clarifying comment confirming Opus 4.6+ adaptive thinking already prevents theinterleaved-thinking-2025-05-14header from being sent (no logic change needed).Tests (
test_opus_47.py,test_fallback.py)test_sonnet_45_gets_1m_header→test_sonnet_45_no_1m_headerand flipped assertion toFalsetest_sonnet_40_no_1m_headerforclaude-sonnet-4-20250514claude-sonnet-4-20250514(Haiku 3 removed from dict)test_sonnet_45_still_adds_context_beta_header_when_enabled→test_sonnet_45_no_longer_gets_context_beta_headerTest evidence
issue-42-validation):_should_add_context_1m_beta("claude-sonnet-4-5-20250929", ...)→False✅_should_add_context_1m_beta("claude-sonnet-4-20250514", ...)→False✅_should_add_context_1m_beta("claude-sonnet-4-6-...", ...)→True✅_DEPRECATED_MODELSno longer containsclaude-3-haiku-20240307✅Check-in note
No dependent repo changes required.
amplifier-bundle-routing-matrixshould be reviewed separately to update any routing that sends long-context workloads to Sonnet 4.5 (tracked in microsoft-amplifier/amplifier-shared#42).