d6da8ca29a
Codex round 1 CBR-001: a head-anchored compaction checkpoint was mis-classified by the log-position step-alignment scan, so a second auto-compaction over a checkpoint-headed surface silently failed. Root cause: `isStepAlignedStart/End` scanned the LOG by seq, but a `replace` op lands a checkpoint at a high log seq whose SURFACE position is the head — its log neighbours (the open step's assistant/message) are not its surface neighbours, so the forward scan wrongly reported mid-step. Fix, per the agreed direction: - Replace the two log-position predicates with one surface-anchored helper `isToolPairingBalanced(nodes, events, beforeSeq)` in `dsh-session` (renamed step-boundary.ts → tool-pairing.ts). A cut is balanced when no unanswered tool-call precedes it on the surface; a region is collapsible iff both edges are balanced cuts. The open-tail and free-node cases fall out of the same counter. It also throws on a corrupt surface (a tool/result with no matching call). - Move compaction off the in-step seam to a new "pre-step" seam fired after turn/start and before step/start, so a compaction's log-only compact/* records and its replacement node land cleanly OUTSIDE any step (the honest structure crash-safety relies on). Renamed the event agent/pre-request → agent/pre-step and switched its dispatch from parallel → serial (listeners mutate the surface as a side effect; serial isolates them so concurrent appends can't interleave). Extended the catalog generator to accept @mode serial. Regression coverage: a real-loop test driving an auto-compaction asserts the landed checkpoint is a balanced cut on both sides; unit tests pin the checkpoint case, the mid-step injection case, multi-call steps, and the corrupt-surface guard. Proven red on the old log-position logic.
core/ — product API spine
The packages every harness build is assembled from: the session log, the system-prompt assembly, the tool registry, the agent vocabulary, and the one concrete loop that drives them. These are product packages — the stable surface plugins and consumers build against.
| Package | Role | ctx key |
|---|---|---|
session/ |
Event-sourced session log + in-memory store | ctx.sessions |
system-prompt/ |
Prompt-section + tool-schema assembly registry | ctx.systemPrompt |
tools/ |
Tool registry + tools/execute waterfall |
ctx.tools |
agent/ |
Agent interface, registry, agent/* event vocabulary |
ctx.agents |
agent-loop/ |
The concrete loop plugin: ReactLoopAgent + the loop driver |
ctx.agentLoop |
agent-core/ |
Bundle plugin: the providerless/executor-less/UI-less spine as code | (loads the spine) |
agent-loop is the one concrete implementation of the agent seam and lives here because it is the harness's default product loop; everything else in core/ is interface/vocabulary. Plugins depend on the agent vocabulary, never on agent-loop directly, so the loop stays swappable.
agent-core is the composition counterpart: one bundle plugin that loads the whole providerless spine (timer + llm + sessions + system-prompt + tools + agents + invariants + tool-bash + agent-loop) and forwards agent-loop's agents list as its own config. App packages (ui/stdio-agent, ui/acp-agent) consume it and add only a front door; a leaf adds only the swappable backends. It lives in core/ because it composes exclusively core/ + interface packages and ships no provider, executor, or UI of its own.