OpenClaw Connector Hardening

Three targeted improvements to the OpenClaw runtime plugin identified by Ant (Discord agent) from production use patterns.

Problem 1 — Temporal Index Content Previews

Change: buildSynthesisIndexBlock (hooks.ts) now appends a summary: <preview> line under each temporal index entry, using the existing trimContent(node.content, 120) helper.

The synthesis prompt’s “do not rewrite” instruction was updated to cover the two-line format.

Problem 2 — Type Safety and Backwards Compatibility

Change: openclaw-types.ts now mirrors the upstream typed hook interfaces (PluginHookAgentContext, PluginHookBeforePromptBuildEvent, etc.) with & Record<string, unknown> intersections that preserve access to undocumented extra fields from older OpenClaw builds.

resolveCtx() replaces six ad-hoc field resolution functions with a single dual-source resolver: typed ctx fields preferred, legacy event extras as fallback.

Legacy dedup: when both before_prompt_build and before_agent_start fire on the same turn without the messages field (older OpenClaw), generation counters (bpbGen/basGen Maps) ensure only one of the pair increments the turn counter. Generation-based tracking avoids the stale-flag problem a Set approach has when before_agent_start misses a turn.

Problem 3 — Mid-Session Extraction for Long-Lived Sessions

Change: New POST /api/hooks/session-checkpoint-extract endpoint. The OpenClaw adapter tracks turns per session; after 20 turns it fire-and-forgets a checkpoint extract without releasing the session claim.

Delta tracking via session_extract_cursors table (migration 049 in TS daemon, 033 in Rust daemon). The cursor is advanced AFTER enqueueSummaryJob succeeds so a crash causes redundant re-extraction rather than a silent data-loss window.

Rust daemon reads cursor and transcript, checks the delta threshold, and returns {queued: false} when a valid delta is found (cursor NOT advanced — no job to pair it with). Summary job queueing and cursor advance are Phase 5 (same TODO in Rust session_end). The {queued: false} response is a documented API variant meaning “delta found, job deferred”; callers treat it the same as {skipped: true} for retry.

Delivered

PR #369 (ant/openclaw-hardening).