A max-tokens response that included a tool call persisted assembler-transformed content next to replay metadata projected from the untransformed native message, so the next request died in history reconstruction with INVALID_REPLAY_STATE and the session stayed permanently stuck. Write side: the finish chunk's replayState becomes a typed ReplayEnvelope — opaque response-level metadata plus optional per-block entries aligned with the emitted block sequence. BlockAssembler computes one keep/drop decision for blocks and entries together, so stored metadata always describes stored content and retained blocks keep their signatures. pi-ai splits its state into a version-2 response half and per-block signature entries. Read side: durable content is authoritative. toPiAssistant degrades any unusable state — foreign kind, other versions (including the flat v1 form already on disk), malformed metadata, or content/block mismatches — to the existing provider-neutral conversion with an onReplayDegrade diagnostic instead of failing the request, which un-bricks sessions poisoned before this change. Covered by assembler and replay unit tests, an agent-loop continuation regression, keyless real-composition continuation tests (native pruned-envelope replay and legacy flat-state degrade), and the authored keyless snapshot scenario max-tokens-continue through the assembled ACP app.
llm/ — LLM capability family
English | 中文
The LLM seam and its provider adapters. The llm package owns both the Service Definition and Consumer roles: the abstract service, content-block vocabulary, and stream-chunk assembler. Provider adapters register on ctx.llm. All product packages.
| Package | Role | ctx key |
|---|---|---|
llm/ |
LLM service and shared streaming vocabulary | ctx.llm |
token-meter/ |
Replay-aware token measurement | ctx.tokenMeter |
llm-retry/ |
Provider-scoped retry policy | listens to agent/request-error |
llm-deepseek/ |
Direct DeepSeek adapter | registers on ctx.llm |
llm-pi-ai/ |
Multi-provider pi-ai adapter | registers on ctx.llm |
Adapters register provider routes on the seam; retry and token measurement remain separate consumers. The child READMEs own routing, metadata, replay, and provider-wire details; the LLM architecture decisions own the rationale.
The subsystem reference — messages and blocks, the model request, the StreamChunk protocol, the adapter contract — is docs/subsystems/llm-streaming.md (token measurement: token-meter.md); see the twin adapters, replay token meter, and routed model context Agent Notes.