The snapshot replay config duplicated most of base.yml + the acp tail just to
swap llm-deepseek → llm-replay. Factor the shared pieces:
- examples/base-core.yml: the providerless provider/tool core (llm, sessions,
system-prompt, tools, agents, invariants, bash-local, tool-bash). base.yml is
now base-core + the llm-deepseek adapter; the snapshot replay config is
base-core + llm-replay. The replay config no longer hand-copies the core.
- examples/acp-agent/acp-tail.yml: agent-loop (no pre-created agents) +
persistence + the ACP bridge/system-prompt, shared by cordis.yml and the
replay config so the three acp-agent configs can't drift. Its persistence root
is `$DSH_SNAPSHOT_SESSIONS_ROOT ?? ./.sessions`.
- Deleted cordis.snapshot-record.yml: recording now reuses the normal cordis.yml
(real adapter), with the harness redirecting the persistence root via env.
start.ts maps DSH_SNAPSHOT=record → cordis.yml.
Verified: snapshot replay 8/8 keyless; record path works through cordis.yml;
ACP e2e no-key boot green through the doubly-nested include (cordis.yml →
base.yml → base-core.yml); coding-agent boots clean; all gates pass.
The goldens now mirror the shape of the surfaces they capture — one compact
JSON record per line — matching the wire (NDJSON stdout) and disk (JSONL
session log) formats, renamed *.golden.jsonl. They stay grep/jq-able and
faithful to what the agent emits, where the prior pretty-printed .txt was a
reformatted representation. Both normalizers drop the 2-space indent; the
normalizer spec asserts the compact form. All 11 goldens regenerated; replay
remains deterministic (8/8 across runs).
Per a design revision, the per-scenario snapshot fixture becomes EXACTLY the
persisted session JSONL (<scenario>/session.jsonl) rather than a hand-authored
llm.json. The log already holds all LLM behavior (assistant/chunk carries every
StreamChunk) AND all harness behavior (tool/call, tool/result, turn/*, usage),
so one artifact drives replay and doubles as a behavioral golden.
llm-replay becomes replay-only (the record-tee is removed; recording is now
"run the real agent once and harvest the .jsonl", done by the harness in a
later commit). deriveReplayScript(events) groups assistant/chunk by (turn,step)
in log order — exact because the loop makes one ctx.llm.stream() call per step
and tags each chunk with the current (turn,step). The two failure modes the log
can't express (a thrown stream — no terminal finish; cancel/hang — timing) use
an optional replay.override.json sidecar.
Hardens against a Codex review finding: a derived group is only valid if it
ends in a `finish` chunk. A group without one is the fingerprint of a thrown
stream() and is NOT silently replayed as a clean stop — deriveReplayScript
throws, naming the (turn,step), so a missing sidecar override fails loud.
Updates the unit tests (parse/derive/load helpers, sidecar override, finish-
terminated grouping, HMR), the example README, and the RFC prose to the JSONL
format. Two goldens (stdout transcript + re-persisted JSONL) and the harness
wiring land in the next commit.
Records the decision to add a third test tier: snapshot tests that boot the
real acp-agent subprocess over ACP stdio, record the LLM's streamed responses
once against the real API, then replay them deterministically so the full
stdout transcript can be diffed against a committed golden — keyless in CI.
Captures the design choices hardened in a Codex (xhigh) review: record at the
provider-neutral llm/stream waterfall; a discriminated fixture entry schema
(chunks/throw/hang) that honors both LLM failure branches; positional replay
with a one-in-flight-stream constraint; per-stream atomic fixture flush (the
subprocess is SIGKILLed, so dispose-time flush would never run); a providerless
replay config; normalize-then-snapshot parsed frames; normalization over an OS
sandbox now with the rootless bwrap/sandbox-exec tier reserved via the
BashExecutor capability seam. Cross-links the proposed determinism RFC
(complementary: internal history invariant vs external protocol contract).
Tianyi Cui