Where we stand

State as of 2026-10-02 (v2.0.0). This page answers five questions in one place:

1. How far is detection from its gates?
2. How does the project now try to close that gap?
3. How does the model work run on ax?
4. What did the tokens cost before and after that move?
5. What is still open?

Every figure is quoted from a committed record. The record's path stands next to the figure. Detail tables stay on the pages linked from each section.

The goal has not changed. The tool should be a safety net on repositories it has never seen. It should say BLOCK or ADVISORY about the code a push would change. It should stay silent on fixes and on benign commits.

Two independent populations have been spent against that goal. An independent population is a set of cases frozen before any scan. Engine recall was 1 of 11 and then 0 of 17. The hand edits that closed misses on the first population did not carry to the second. So the question is no longer which rule to add next. The question is this: how can a change to detection be shown to work on code it was not tuned on? And can that be done at a cost per candidate that can be paid for every push?

The answer this page records:

• The pre-push safety net is NO-GO against every M4 gate.
• The project has stopped trying to reach the gates by hand.
• Every detection change now has to win a controlled measurement on held-out repositories. The measurement runs on an agentic plane whose cost per candidate is known.
• The pieces of that method exist and have been measured. None of them has produced a BLOCK decision yet.

1. Detection capability and goals: NO-GO, measured

No M4 gate is met on an independent population. M4 is the qualification milestone for the pre-push safety net. It requires all of these together:

• at least 95% actionable precision;
• at least 90% supported recall;
• at least 95% supported-check completion;
• the runtime gates;
• zero fixed-side or benign false alerts.

A population is frozen before any case is scanned. It is scored once under a pre-registered protocol, then spent. After that it can inform changes but can qualify nothing (Evaluation).

Gate	Required	Latest independent result	Record
Supported recall	>= 90%	engine 0 of 17 declared sites on population v2	benchmarks/independent/results-v2.json
Actionable precision	>= 95%	engine 0 of 17 (precision); the tool hunter on the same population 2 of 14	results-v2.json, results-v2-hunter.json
Supported-check completion	>= 95%	13,206 of 108,374	results-v2.json
Fixed-side and benign alerts	zero	0 fixed-side, which the record calls met trivially since nothing was detected; 3 benign alerts	results-v2.json

Three later measurements narrow the picture. They do not change the verdict.

• The plane reproduces the script pipeline's agreement at a known cost. The test used the model-driven pipeline's validation set: 46 candidates, 15 cases of v2, 20 declared vulnerable sites. The plane ran verify passes a and b, plus a tie-break on the 10 disputed candidates. It agreed on 16 of 20 declared sites. The script reference agreed on 16 as well. The cost was $0.0205 per candidate (benchmarks/independent/plane-increment-2.json). The record carries two caveats:
• The tie-break was chosen after seeing the first measurement on the same set. So this compares plane with script and qualifies nothing.
• The passes flag fewer declared sites than the reference in any pass: 17 against 19 (passes against reference). That count is a correction in plane-increment-1.json. Its first reading took agree's declared_sites_matched (19, coverage by candidates) to mean "found in either pass".
• The learned decision engine ranks, but may not block. It was evaluated on six families, on repositories the compiled program was not shown.
• The pooled AUC (area under the ROC curve) of its score runs from 0.77 (injection) to 0.96 (access control).
• The stricter reading is the within-pair AUC. It asks whether the vulnerable side of a fix scores above its own fixed side: 0.72 to 0.93.
• BLOCK is offered for no family. Calibration holds only for output encoding. There, no fold reaches the required precision (benchmarks/measurements/2026-10-02-decision-engine-slice-2/record.json).
• The per-family table is on Decision engine.
• PHP coverage is in-sample. The PHP quick rules were written and tightened while looking at the pins and fixtures they are scored on. The record says so itself (provenance.in_sample in benchmarks/measurements/2026-09-30-php-quick-rules/measurement.json). It is a development check, not a recall estimate. On real PHP code, the Joern engine is the instrument.

What has not been touched: population v3, 15 PHP cases, frozen as the one-time final check.

• No development or analysis work reads its cases.
• A test fails when anything in the tree names one of its repositories.
• It runs once, after a prediction is committed.

2. Our approach to detection, step by step

The path changed because hand edits did not transfer. Every gain before 2026-09-30 was a hand edit after a miss: a rule, a taint vocabulary entry, a guard, a prompt line, a tie-break. Each was tuned on the cases that exposed it. The tuning measured on population v1 did not carry to v2 (1 of 11, then 0 of 17).

The conclusions drawn:

• Hand edits do not transfer.
• The data that could teach a better decision cannot be produced by hand at the scale needed. It has to be harvested and labelled by machinery with a boundary around it.
• Framework knowledge (which function is a sink in which framework) is useful as a prior. But it must stay optional. Otherwise the engine learns the vocabulary instead of the code.

A reader might object that a classifier is slower to show gains than the next rule. It is. The difference is where its gains are measured: on repositories it never saw. Rules were not measured there.

The chain has one job per step. The design is on Memory and detection. This list is the order of operations.

1. Instruments produce signals, never verdicts. Each instrument writes one block of a candidate's record. None decides alone. The instruments are:
2. quick rules;
3. the Joern engine;
4. model sink classification;
5. the plane's verify passes a and b, with the tie-break c;
6. repository facts (callers, spans);
7. model source/sink/sanitizer roles.
8. Feature records are allow-listed, and missing is not zero. A candidate is (path, function, family) of one repository and pin.
9. An instrument that did not run, had no coverage or failed records that state. "Silent" and "did not look" stay distinguishable.
10. Input profile v1 withholds the engine block and the function length. A leak audit found that they separate the two sides of a pair by construction (benchmarks/measurements/2026-10-01-decision-engine-leak-audit/).
11. Since 2026-10-02 it also withholds the plane's verify.flag_b and ms.operation. The audit of the plane profile flagged them the same way (2026-10-02-decision-engine-harvest-advisory/record.json, src/openultrasast/learn/schema.py).
12. Labels come from ground truth only. A fail-closed allow-list (src/openultrasast/learn/sources.toml) names the sources:
13. the spent populations' declared sites and fix ranges;
14. the vulnerable and fixed sides of pairs, including the 97 real public fixes in benchmarks/pairs/advisory-fixes/;
15. benign controls;
16. recorded adjudications.

Assumed-benign commits are their own source. They are weighted 0.5 and reported separately. A plane verdict is a feature, never a label. "Rejected by the plane" is not a negative. Otherwise the engine would learn to reproduce the plane's mistakes. 4. Retrieval finds similar labelled cases. It uses a Gower distance (a distance for mixed numeric and categorical data) over the signal profile. Results are re-ranked by cosine similarity of code embeddings. The embeddings are OpenAI text-embedding-3-small through OpenRouter, cached by excerpt hash. The evaluation boundary is the only door into a prompt. It never admits the candidate's own repository group, or a group the fold evaluates. 5. A classifier compiled in house, DSPy-style. The program is retrieve -> classify(k). The prompt holds, in order: - an instruction and compiled demonstrations (a fixed prefix, so the provider's cache hits); - the retrieved examples; - the candidate's excerpt and signals.

The model answers vulnerable, not vulnerable or unsure, with a rationale that cites a line. k samples give a score. One program is compiled per profile and family, on a compile split that is never evaluated. 6. Calibration on held-out repositories. Platt scaling (a logistic fit) maps the score to a probability. It is cross-fitted by repository group, so no map is checked on the fold that fitted it. Calibration holds when three conditions are met: the slope interval contains 1, the intercept interval contains 0 and ECE <= 0.05. 7. Two operating points. BLOCK applies only where calibration holds and a fold reaches the required precision. Otherwise the point is ADVISORY. An unsure majority can never BLOCK. 8. A/B experiments are the only way a change is adopted. Prompts, models, pass counts, features and sampling are compared under a pre-registered manifest. The manifest fixes frozen units, paired arms, a repository bootstrap and two looks. exp-002 is the first to finish: - It compared a retrieval ensemble (five samples over disjoint example sets at temperature 0) with today's temperature sampling. - It raised re-run agreement a little (0.906 against 0.875, interval spanning zero). - It lowered the within-pair AUC from 0.815 to 0.741 and cost 2.4 times as much per candidate ($0.0051 against $0.0021). - Decision: REJECTED (benchmarks/experiments/exp-002-retrieval-ensemble/result.json). 9. Extrapolation with intervals. Every number carries a 95% repository-cluster bootstrap interval. Both the pooled and the within-pair readings are reported. The stricter one is named. 10. The one-time v3 check. It happens when a program is adopted and a prediction is committed. Then population v3 is scored once under benchmarks/independent/protocol-v3.md.

3. AI integration: ax on the server

All model work runs as Tasks on google/ax over Agent Substrate. They run in a single-node kind cluster on the maintainer's host. Each Task runs in its own gVisor sandbox. There is no local subprocess path.

The reconciler (ousast plane run) is a host process. It does five things:

1. applies a Run's Workspaces and Tasks;
2. resumes each Task;
3. sends its start signal;
4. collects its artifacts;
5. records state.

Flow and contract: The plane on ax. Bring-up and the host's lessons: ax on this host.

What each Run guarantees:

• One Model and one budget per Task. A Task binds at most one ax Model and budget: {usd, calls}. The Models are deepseek-flash for chat and openrouter-embedding for embeddings. The metered client refuses the next call at the ceiling. The task ends unfinished and resumes on a rerun. Model-free tasks run with a zero budget, so a stray call fails loudly.
• Credentials exist only in the start request. Agent Substrate boots each template once as a golden actor. So the runner never starts by itself. It waits for POST /ousast/v1/start. The reconciler sends that request through atenet-router to that actor alone.
• The key is read from the operator's environment or .env.
• The runner keeps it in memory and passes it to the command.
• It is redacted from echoed stderr.
• No manifest, rendered Task or file carries it.
• Per-task egress. Each actor gets one EgressPolicy through the atenet-egress gateway. It is deny by default and uses hostnames only. It allows plain HTTP to the artifact receiver. It allows TLS passthrough to the Workspaces' Git hosts and the Model's declared hosts. It is deleted with the actor.
• Artifacts come back through the gateway. The runner posts its output directory as a tar to the receiver. The receiver is an HTTP server inside the reconciler process on the host. It is reached through a Service with an EndpointSlice to the host. That delivery is the task's completion; ax has no Completed phase.
• Memory on S3-compatible RustFS. The setting is OUSAST_MEMORY=s3://sast-memory on a RustFS server.
• The store verifies the bucket at every start: versioning, lifecycle, tags, S3 Select.
• It refuses to start when anything is missing. There is no local or fetch-and-filter fallback.
• Each row kind has a fixed set of queryable fields, enforced at write time (Memory, RustFS setup).

Lessons the host taught, each from a failed live run (the full list is on ax on this host):

• Substrate installs no WorkerPool, and actor images must be pinned by digest.
• A release ax CLI skews from the server. Build it from the deployed checkout.
• ax has no Completed phase, so completion is our artifact delivery.
• The golden boot means the runner must wait for a start request.
• The egress gateway dials the address the actor connected to. So the receiver is a Service, dialled by ClusterIP with its name as Host.
• ax's snapshot bucket must exist in your S3 server. When it did not, deleted golden actors piled up in DELETING. They filled the disk during a 600-task harvest on 2026-10-01.

Deployment status uses two words, as Deployment does, strictly.

Implemented:

• ax as the only executor;
• per-task EgressPolicy;
• credentials only in the start request;
• per-task budgets and attribution;
• the S3 store verified at startup;
• local bring-up, doctor and smoke Run;
• re-pinning generated Tasks to another registry.

Planned, not done:

• deployment to any cluster other than this host's kind cluster;
• a configurable kube context (kind- is hard-coded in doctor.py, egress.py, router.py);
• the receiver as an in-cluster Deployment;
• the reconciler in-cluster with Secrets injected;
• presigned-URL delivery to the store.

4. Token economics, before and after

Before the plane, two costs stood out:

• The script pipeline cost $0.022 per candidate for two verify passes (benchmarks/independent/verifier-batched-check-2026-09-29.json).
• The maintainers' own coding sessions spent about 90% of their tokens on tool input and output rather than reasoning.

After it, the per-candidate costs below are what the records show. The mechanisms are on Token ergonomics: one budget per Task, pay-once reuse, cheap-before-expensive ordering and replay at $0. This table is the before and after.

Item	Before	After	Record
Verification, two passes per candidate	$0.022 (script pipeline)	$0.0205 over 46 candidates with the recorded triage, including the tie-break pass on 10 disputed; 2,385,152 of 3,820,395 prompt tokens were cache hits in increment 1 (62%)	verifier-batched-check-2026-09-29.json, plane-increment-1.json, plane-increment-2.json
Decision per candidate (classifier, k = 5)	none existed	$0.0032 per evaluated candidate on the injection slice; $0.0027 to $0.0032 across six families	2026-10-01-decision-engine-injection-slice/record.json, 2026-10-02-decision-engine-slice-2/record.json
An A/B arm, per candidate	none existed	$0.0021 (temperature sampling) against $0.0051 (retrieval ensemble); the cheaper arm won	benchmarks/experiments/exp-002-retrieval-ensemble/result.json
Harvest of plane signals for the engine	none existed	verify $2.5373 over 1,961 calls and 474 tasks; roles $1.4036 over 1,034 calls and 151 tasks	2026-10-01-decision-engine-harvest/record.json
Development transcript, tool I/O share	90%	85.5% over 2,701 tool calls (dev_token_report)	plane-increment-1.json

Two notes from the records:

1. The meter prices every call at the Model's list price (plane/models/deepseek-flash.yaml). The DeepSeek account moved less: about one third of the metered amount on the injection slice ($0.30 for $0.91 metered). Budgets and gates are set against the meter, never against the balance.
2. The development share barely moved: 90 to 85.5 is a small gain. The remedies are a read guard, a bulk reader and scripts in files. They target file contents, because that is where the tokens go.

5. Open items

There are five groups. Each item has its record. The groups are the engine's own gates, data, measurement debt, infrastructure, and instrument gaps.

The engine's gates.

• BLOCK is reachable for no family. Calibration fails for five (ECE 0.071 to 0.119). The sixth reaches no fold with a Wilson lower bound of 0.95 on precision (slice-2 record).
• Re-run agreement is below 0.9 for three families: injection 0.77, access control 0.83, untrusted destination 0.87. exp-002 tried the obvious variance fix and lost on the ranking.

Data.

• Positives-only groups: 98 (family, group) pairs in the 904-example memory hold positive examples and no negative.
• 94 of them exist because the fixed side no longer has the function (the vibe-py pairs).
• No advisory-fixes group is among them (benchmarks/measurements/2026-10-02-decision-engine-negatives-gap/record.json).
• There are no single-label negatives. So every family's pooled AUC is inflated by positives that never had to be told apart from their own fix (slice-2 record, paired_groups_check).
• The model has seen public fixes. A verify pass named the advisory's CVE id for a public fix. The engine's design specification (maintainer tooling) records this as visible memorisation. Excerpts now redact advisory ids and security-worded comments (src/openultrasast/learn/excerpt.py). But labels drawn from public advisories are partly in the model's training data, and the within-pair numbers carry that.
• PHP is covered by the engine on real code and by in-sample quick rules. The population that would measure it (v3) is reserved.

Measurement debt.

• exp-001 (known callers) is registered and has not run. Its units need model-free candidate generation on the 41 development repositories. That generation is not built (benchmarks/experiments/exp-001-known-callers/registration.json).
• Leave-one-source-out, leave-one-framework-out and the memory-size curve points (0, 25, 50%) have not run. One paired point exists (724 against 904 examples, injection, AUC 0.76 against 0.77).
• The plane-profile leak audit flagged verify.flag_b and ms.operation. They are withheld from profile v1. Before any plane-profile program runs, someone must decide whether they track the label on unseen code (2026-10-02-decision-engine-harvest-advisory/record.json).
• Population v3 waits for benchmarks/independent/prediction-v3.json, which does not exist. It is written only after a program is adopted.

Infrastructure.

• Deployment to a separate Kubernetes cluster is planned, not done. The code changes it needs are listed with file paths on Deployment.

Instrument gaps.

• A missing provider key is a quiet path in a scan.
• The plane refuses to start a Task whose Model names an unset variable (plane/router.py, StartError).
• A scan without a key asks the model nothing and reports only the graph's entailed findings. It records learning_endpoint_unavailable in manifest.json (cli.py, after resolve_chat_endpoint returns nothing).
• report.md has no line for that reason yet. So the report does not say the model layer was skipped.