rea/experiments/atomic-codemode/path-query-study.md

Recovered graph paths as composable evidence

The frozen controller question already completes correctly in both adapters. However, answering four path-witness subquestions makes the model read many neighbourhoods or the entire 1,229-block inventory. The missing query is graph reachability under explicit exclusions, not a SQLite-specific investigation.

path({snapshot,from,target:{kind:"block",id}|{kind:"exit"},avoid,offset,limit}) returns one shortest edge-count witness. Equal-length choices keep native edge order. An exit is a zero-successor recovered block. Rows retain their original edge identity, native successor index, source operation, condition and polarity; step_index separately identifies the position in this path. Snapshot-local IDs plus Evidence identify the source. Complete native Evidence remains accessible. This derived view composes identified blocks/edges; it is not a runtime execution or a proof that predicates are jointly satisfiable.

The validated graph owner supplies its existing block/outgoing indexes to a provider-independent reader. Shared session contracts expose the same method through SDK, CLI, direct MCP and Code Mode. There are sixteen fact methods, nineteen direct tools and four Code Mode tools. No native exporter change is needed. Projection-only/malformed graphs keep their typed recovered-IR failure and retained Evidence. Unknown start, destination or excluded identities return unknown, an explicit missing selection and a null total. A known excluded endpoint gives not-found under that exclusion. A zero-edge found path and an empty page remain distinct from absence.

Iterative BFS uses O(V+E) time and O(V) transient state. The graph is already admitted at at most 12,000 blocks and 50,000 edges; the avoidance selection shares that block bound. One last-query cache per resident immutable graph includes start, target and normalized exclusions, independent of paging. It replaces on query change, disappears with graph eviction/lease close, and does not retain arbitrary missing-query keys. The existing owner retains at most two graphs.

Executed correctness and local costs

An independent Floyd-Warshall oracle checks all 512 three-node directed graphs, all eight exclusion sets and all start/block-or-exit requests: 49,152 queries. Separate cases cover parallel edges/native ordinals, loops/no exits, missing identities, exclusions, zero-edge paths, paging, immutable rows, cache replacement, fresh owners and a 12,000-block chain. The atomic JS suite passes 74 tests. Native-boundary tests preserve code/facet errors for malformed/projection-only captures. Both actual SDK-converted MCP catalogs/schema sets pass Draft 2020-12 compilation and good/bad named path inputs; every declared tool is advertised. Lint has no warnings and formatting passes.

Both real SQLite MCP adapters return the four expected witnesses in the unchanged question/oracle, including both bypasses that avoid block 1159. Every returned edge field equals the retained native graph; the complete function equals the previous compressed-graph golden. Paging, zero-edge success, graph-relative absence and unknown exclusions pass. This establishes producer fidelity and recovered-graph correctness, not full machine flow, feasibility, termination, memory aliases or provider parity.

Same-capture phase	Direct wall / CPU ms	Code Mode wall / CPU ms
First four path queries	64.00 / 64.01	60.73 / 60.77
Repeat all four (last-query cache churn)	9.54 / 9.50	26.58 / 26.50
Same-query cached page	2.70 / 2.71	10.79 / 10.80
Historical all-block read + consumer composition	27.67 / 27.66	47.40 / 47.39

The historical verifier completes the same four witnesses with ten fact reads; the new method needs four. Direct MCP returns 271,535 bytes across ten calls for the baseline and 9,309 bytes across four for the new queries. Code Mode composes each group in one MCP call; its old witness-only result is 1,031 bytes versus 7,539 for the new complete path/provenance replies. Fields/envelopes differ, and bytes are not tokens. First-query/JIT effects and fixed execution order are not controlled. In particular the first new-query group is slower than the later baseline in both lanes: these observations do not establish a speedup.

Fresh native captures take 38.499 seconds in Code Mode and 42.556 direct; this query does not accelerate native analysis. Entire verifier families cost 40.406 wall / 40.185 CPU seconds / 656.4 MiB and 44.419 / 40.033 / 653.7 MiB, respectively. Final 74 tests cost 8.376 wall / 4.098 CPU seconds / 83.5 MiB; metadata verification costs 1.730 / 1.560 / 135.9 MiB. All have OOM/kill zero and verified cleanup. Family kernel peaks include charged file cache, not RSS.

Main was refreshed to 8116dc065 before this feature. Its cached runtime build passes (39.075 wall / 37.676 CPU seconds, 3,073.9 MiB kernel peak, OOM/kill zero, verified cleanup); the peak includes charged cache and crossed the soft memory high watermark under the 4 GiB hard bound. An earlier unpinned Node 20 build attempt failed on node:sqlite before this pinned build; it is not counted as a passing check. Full repository/native gates were not run. Raw evidence remains local as path-* under .cache/atomic-codemode/; no binaries are committed.

Frozen model protocol

Reuse the exact controller question/oracle frozen at 8d13c67e7, the same SQLite artifact and a9ca8a8a... engine, requested model/client/settings and common non-answer-bearing discovery/wait guidance. Freeze the complete runtime before both isolated model calls. Generate both enabled-tool manifests from the actual catalog, including the new direct method. Run Code Mode then direct with fresh leases/caches. Preserve prior pairs and every attempt; review full answers and source/witness identity before interpreting cumulative/cached/uncached tokens, output, reasoning, elapsed time, CPU and family peak memory. OS/model caches and host contention remain uncontrolled. The new shared method may help either lane; no preferred adapter or broad complex-software superiority is presumed.