Description
Anyone running a coding agent for hours knows where the bill comes from. An edit is almost always followed by a predictable validation command — two model round trips for one intention. A 40 KB log read once gets replayed verbatim on every subsequent request. Finished subtasks sit in active context refusing to leave. And sometimes a whole frontier-model call is spent reading a log to find the three lines that matter next.
SoL-Pi is an NVIDIA research extension that installs on top of the Pi coding agent to deal with exactly those four. Its origin is unusual: the team was working on scaling auto-research loops when a question surfaced — before scaling the loop, could an agent first make the harness it runs on cheaper? Search over 535 executable environments left four mechanisms standing, and this open-source release is those four.
They act at different points. Action Fusion lets an edit carry its follow-up validation command in the same tool call. ObservationPack turns repeated large results into stable handles with exact paged recall. Evidence-Preserving Reducer compacts long diagnostic logs into short receipts, but only when every retained quotation matches the archived source word for word. Online Context Compact marks completed plan steps as candidates for Pi native compaction.
A few design rules are worth stating. No Pi patches and no vendored Pi source — only public extension APIs. Every mechanism is disabled by default, so a missing config file means nothing is on. Original observations stay available locally, and a failed reduction leaves the result untouched. What is saved is repeated turns and replayed context, not verification, evidence or finishing the job. MIT licensed; needs Node.js 22.19 or newer and the matching Pi release.
Action Fusion: An edit or write can run its follow-up validation command inside the same tool call, removing a round trip that was always going to happen.
ObservationPack: Repeated large text results become a stable handle plus a short excerpt, with the full output archived locally and recalled exactly by id and offset when needed.
Evidence-Preserving Reducer: Long diagnostic logs compact into short receipts only if every retained quotation verifies against the archived source; a failed reduction leaves the original untouched.
Online Context Compact: Completed plan steps become compaction candidates subject to cost and window-pressure checks, handed to Pi native compaction, after which the task continues in a new turn.
Opt-in by default: Nothing is enabled without explicit configuration, and project-level config takes precedence over user-level without merging the two.
No changes to Pi: Built entirely on public extension APIs, with authentication, provider URLs, the main model and shell behaviour left under Pi control.
Local archives: ObservationPack and the reducer keep their archives under the session directory; remote reduction is a separate decision to make before enabling it on sensitive logs.
SoL-Pi is an NVIDIA research extension that installs on top of the Pi coding agent to deal with exactly those four. Its origin is unusual: the team was working on scaling auto-research loops when a question surfaced — before scaling the loop, could an agent first make the harness it runs on cheaper? Search over 535 executable environments left four mechanisms standing, and this open-source release is those four.
They act at different points. Action Fusion lets an edit carry its follow-up validation command in the same tool call. ObservationPack turns repeated large results into stable handles with exact paged recall. Evidence-Preserving Reducer compacts long diagnostic logs into short receipts, but only when every retained quotation matches the archived source word for word. Online Context Compact marks completed plan steps as candidates for Pi native compaction.
A few design rules are worth stating. No Pi patches and no vendored Pi source — only public extension APIs. Every mechanism is disabled by default, so a missing config file means nothing is on. Original observations stay available locally, and a failed reduction leaves the result untouched. What is saved is repeated turns and replayed context, not verification, evidence or finishing the job. MIT licensed; needs Node.js 22.19 or newer and the matching Pi release.
Features
Action Fusion: An edit or write can run its follow-up validation command inside the same tool call, removing a round trip that was always going to happen.
ObservationPack: Repeated large text results become a stable handle plus a short excerpt, with the full output archived locally and recalled exactly by id and offset when needed.
Evidence-Preserving Reducer: Long diagnostic logs compact into short receipts only if every retained quotation verifies against the archived source; a failed reduction leaves the original untouched.
Online Context Compact: Completed plan steps become compaction candidates subject to cost and window-pressure checks, handed to Pi native compaction, after which the task continues in a new turn.
Opt-in by default: Nothing is enabled without explicit configuration, and project-level config takes precedence over user-level without merging the two.
No changes to Pi: Built entirely on public extension APIs, with authentication, provider URLs, the main model and shell behaviour left under Pi control.
Local archives: ObservationPack and the reducer keep their archives under the session directory; remote reduction is a separate decision to make before enabling it on sensitive logs.
