AgentCore 0.14.0

Added

• AnthropicClient and build_protocol_client accept prompt_cache_ttl (5m, the API default, or 1h), which sets the lifetime of both prompt-cache breakpoints the adapter places. Blank and 5m omit the field, so an unconfigured consumer's requests are byte-identical to before; ANTHROPIC_PROMPT_CACHE_TTL provides a deployment-wide default for construction sites a profile does not reach, and a client's own value outranks it. Unsupported values (30m, numbers, a stray unit) raise ValueError at construction rather than silently reverting to five minutes, which would only surface as a cache-hit-rate regression. The existing ANTHROPIC_PROMPT_CACHE=0 kill switch still wins, and 1h writes were already counted by the adapter's cache-write accounting.

  Consumers should set this per model, not globally: an hour costs 2x base input to write against 1.25x for five minutes, and it pays off only when one TURN can take longer than the shorter window — a cached entry expires relative to its last use. In ApodexHarness's 2026-10-05 GDPval batch, 12.9% of claude-opus-5-5 turn gaps at effort=max exceeded 300s and those calls missed the cache 35.7% of the time against 9.5% for the rest, rewriting a median 81k tokens each; a fast model has no such rewrites to avoid and would only pay the higher write rate. A gateway has to forward the field: llm-hub was verified on 2026-10-05 (HTTP 200, write billed to the 1h bucket, a read at 548s still hitting while the 5m control had expired), and the extended-cache-ttl-2025-04-11 beta header was not required.

• LoopConfig.stream_llm_tokens (None by default) overrides the loop's own choice of transport: True streams the turn, False does not, None keeps the existing automatic selection (the reasoning-only watchdog or an observer's wants_llm_delta). It exists because the transport can be the reason to stream rather than any observer — a gateway that abandons a non-streaming request while waiting for response headers leaves no alternative, and for native Anthropic those headers arrive only when generation finishes. Measured on llm-hub's "Claude Code" channel on 2026-10-05, an identical claude-opus-5-5 request at effort=max returned 502 upstream_unreachable — first byte timeout after 76s non-streaming and HTTP 200 when streamed (first byte 3.9s, generation 242s); concurrency was ruled out.

  Behaviour change in automatic mode: anthropic now streams when deltas are requested, where all three native protocols were previously suppressed unconditionally. That suppression predated, by one day, the provider substrate work that made AnthropicClient.stream rebuild the verbatim block list (trailing signature_delta, redacted_thinking) so a streamed turn replays like its non-streaming twin — test_anthropic_latest_models.py has covered it parametrized over streaming ever since. responses and bedrock keep the old behaviour as UNVERIFIED_STREAM_PROTOCOLS (exported) until a test proves their streamed replay; removing one from that set is that test's job. Consumers whose Anthropic-protocol profiles set reasoning_only_* or register a wants_llm_delta observer will now actually stream — their client must implement stream, since there is no fallback to chat.

  The suppression is also no longer silent: when automatic mode drops deltas something asked for, the loop warns. ApodexHarness's tests/contract/test_streaming_deltas.py documents the old selection expression verbatim in its docstring and should be updated when the pin moves.