dpskh/dsh-rewind

One package, one entry plugin. Mounting @dpskh/tool-rewind provides ctx.rewind (a service that folds everything since the most recent checkpoint mark into an auto-generated report) and the model-facing rewind tool over it. The fold shadows the exploration's surface range with the report — the same surfaceOp: { op: 'replace' } mechanism the DeepSeek Harness compaction seam uses — so subsequent requests no longer carry the exploration's intermediate steps (reads, searches, experiments), while the durable log keeps the full exploration for audit. The report is produced by ctx.llm (auto-generated); the mark is owned and served by the sibling @dpskh/tool-checkpoint plugin (ctx.checkpoint.latestMark / hasActive / completeFold). This plugin writes no session events of its own — the fold commits only the core-vocabulary user/message replacement, so the durable session log stays readable by any harness. No upstream package is modified.

Configuration

- id: tool-rewind
  name: '@dpskh/tool-rewind'
  config:
    toolName: rewind                # model-facing tool name (default rewind)
    maxTokens: 1024                 # summarization output budget
    maxSummarizationRetries: 2      # empty-completion retries before failing
    summarizationProvider: deepseek # optional override of the routed provider
    summarizationModel: deepseek-chat
    reportLanguage: en              # en | zh (report instruction language)

Provider/model resolution order for the report call: configured overrides, then the session's last routed request/header config, then the agent's options. Missing all three fails loud.

The report call runs with thinking disabled when the route exposes an off reasoning effort — condensing an exploration is mechanical, and a reasoning model's thinking tokens otherwise compete with the report text under maxTokens (thinking can exhaust the budget before any text starts, leaving an empty completion). Empty completions retry up to maxSummarizationRetries; an exhausted budget rejects with a message carrying the finish reason and token usage, which the rejection message preserves.