dsh-funnel

Every tool result is appended to the conversation and re-sent on every subsequent model request. A 500-line test run, a large file read, a web scrape — all of it rides along for the rest of the session, burning tokens, filling the window, and burying the one assertion error that actually matters. Existing truncation and compaction layers either only cover shell, fire only after the budget is blown, or perform a blind head-tail cut without preserving error lines.

dsh-funnel cures results at the moment they enter context: it keeps the head, the tail, and every error or warning line, then spills the middle to local disk with a path pointer. In a real headless session a 2001-line bash result reached the model as 370 characters — every later turn pays for 370 instead of 8,893. The spill file is not deletion; in testing the agent read the spill file on its own to recover an omitted middle line. Curation is pagination, not loss.

It fits developers running long agent workflows with heavy-output tools (tests, builds, scraping, batch file reads). Zero configuration, byte-identical passthrough under the threshold, error results never touched, and complementary to rather than replacing the official compaction layer.