Long-running work accumulates material: the original goal, later constraints, attempted routes, failed experiments and current progress. Sending everything again on each continuation repeats more and more content; keeping only a summary can make the original basis of a decision difficult to recover.
-LoopX's context delivery separates these jobs: preserve complete sources, read the facts needed for the current decision, expand supporting material around questions, and reuse unchanged structures exactly within a valid compaction cycle.
-Results first: progressive reading, deltas and task ablation
-Eight tasks: progressive reading and in-cycle deltas
-This section recalculates the published eight-task Four-Arm Context ON 18h aggregates to distinguish Progressive and in-cycle Delta transport costs. The source reports 213 model-facing wakes: 101 new-session or post-compaction baseline reads and 112 in-cycle continuations. Per-task cells retain the published values; totals are recomputed from those cells. Raw per-wake logs are not included here.
+Context delivery
An Agent needs a way to look things up, too
Read necessary facts first, reuse verified structures within a compaction cycle, and recover the complete baseline when continuity is lost.
Long-running work accumulates material: the original goal, later constraints, attempted routes, failed experiments and current progress. Sending everything again on each continuation repeats more and more content; keeping only a summary can make the original basis of a decision difficult to recover.
+Selective JSON Pointer lookup by itself is straightforward—it folds long-tail history not needed for the immediate decision. The core mechanism in LoopX's context delivery is compaction-cycle-bounded structured delta context: complete sources are saved first, unchanged typed subtrees are reused exactly against a verified baseline within the active context_epoch, and any host compaction or digest mismatch atomically resets to a fresh complete baseline rather than chaining dangling deltas.
Evidence: separate context comparisons, cycle deltas and task ablation
+Four mechanisms, with separate measurement baselines
+Complete capture, Progressive views, compaction-cycle structured Delta and a bounded --initial-read are composable mechanisms, but their bytes do not decrease monotonically for every input. Delta requires a verified same-cycle baseline; a new epoch, mismatch or smaller full representation uses complete delivery. The archived tutorial below measures three independent comparisons, not a same-source four-stage cascade.
Separate tutorial comparisons and 18h compaction-cycle Delta observations
measurements.json: the necessary view is 5,107 / 57,014 B (9.0%); the next capture's Delta file is 2,164 / 5,543 B of its full Progressive delivery file (39.0%); manually selecting three paths from the separate 51,547 B capture.json returns 674 B (1.3% body), or 1,362 B including CLI metadata (2.6%). The 674 B is not a measured --initial-read after Progressive + Delta. These saved observations belong to the revision recorded in measurements.json; output size may change with source revision and reader paths. B1: ANN's archived 18h pairs compare Delta against selected packets, with 38.54% reduction across 46 events and 74.25% across 24 in-cycle Delta events. B2: Eight-task aggregates retain the separate 213-wake and 112-continuation denominators; their percentages cannot be chained into this tutorial.Eight tasks: single-layer payloads (Progressive / lossless Delta file) vs stacked first-read
+When reading the published eight-task Four-Arm Context ON 18h table below, separate single-layer file payloads from the stacked first-read entrypoint. Across 213 model-facing wakes (101 new-session or post-compaction baseline reads and 112 in-cycle continuations), the published “In-cycle Delta payload” column (4.49 MB / ≈ 12.53 MB = 35.8%) measures the unprojected lossless delivery.json file on disk (All → Delta)—a parallel single-layer cut alongside “Progressive projection” (7.29 / 22.41 MB = 32.5%, All → Progressive), not stacked Progressive + Delta. Both mechanisms stack in the final column, Prog+Delta first-screen (3.0% body / 5.0% CLI). Per-task cells retain the published values; totals are recomputed from those cells without raw per-wake logs.
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- Progressive reading: across all 213 wakes, full packets fall from 22.41 MB to 7.29 MB (−67.5%). The projection retains 32.5% of original bytes, with a per-task range of 26.5%–39.0%; unselected candidates and historical detail remain available on demand. -
- In-cycle deltas: across 112 continuations, corresponding full packets fall from approximately 12.53 MB to 4.49 MB (−64.2%). Deltas retain 35.8% of same-wake full bytes, with a per-task range of 20.7%–47.1%. -
- Progressive + delta first read: for those same 112 continuations, the
--initial-readbody carries 3.0% of original bytes, or 5.0% including the CLI JSON envelope (−97.0% / −95.0%). First-read size is not whole-episode model input.
+ - Single-layer progressive view (All → Progressive): across all 213 wakes, full packets fall from 22.41 MB to 7.29 MB (−67.5%), retaining 32.5% of original bytes (26.5%–39.0% per task) while keeping unselected candidates and historical detail expandable on demand. +
- Single-layer lossless delta file (All → Delta): across 112 continuations, unprojected lossless delta files fall from approximately 12.53 MB to 4.49 MB (−64.2%), retaining 35.8% of same-wake full bytes (20.7%–47.1% per task). +
- Stacked entrypoint (Progressive + Delta First Read): for those same 112 continuations, stacking progressive selection with compaction-cycle deltas brings the
--initial-readbody to 3.0% of original bytes, or 5.0% including the CLI JSON envelope (−97.0% / −95.0%). First-read size is not whole-episode model input.
8-task Four-Arm Context ON byte ratios (N = 213 wakes, 112 in-cycle Deltas)
8-task Four-Arm Context ON byte audit (N = 213 wakes, 112 in-cycle continuations)