feat(agent): cache control embedding index + auto-wire semantic pass (gated)

Item 2 of the semantic-mapping follow-ups.

Caching (2a): ControlIndex::load_or_build persists the embedded corpus to
snapshot_dir keyed by a corpus hash (control ids + requirement text). A later
scan reuses the embeddings unless the catalog changed, turning the per-scan
re-embed of the ~13.6k master-control corpus into a one-time cost. Atomic
write (temp + rename); self-invalidates on catalog change. ControlCheckSpec
gains Serialize/Deserialize to persist.

Auto-wire (2b): orchestrator Stage 5c runs semantic_stamp_findings after control
triage, gated on breakpilot.semantic_mapping (env BREAKPILOT_SEMANTIC_MAPPING,
default off). Stays off until verified live against a deployed master-controls
catalog; safe no-op meanwhile (the endpoint 400s pre-deploy and the pass warns +
returns 0).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

compliance-agent/src/api/handlers/oscal.rs

@@ -1,9 +1,9 @@
 //! OSCAL assessment endpoint.
 //!
-//! Assesses a target's findings against the breakpilot-compliance control
+//! Returns a standard OSCAL assessment-results document for a target's findings,
-//! catalog and returns a standard OSCAL assessment-results document. Ties
+//! driven by each finding's stamped `control_refs` (from the scan's control-triage
-//! together the ingest provider ([`OscalControlsProvider`]) and the assessment
+//! stage): mapped findings target their controls, unmapped findings are reported
-//! emitter (`compliance_core::models::oscal_assessment`).
+//! as-is. See `compliance_core::models::oscal_assessment`.
 
 use axum::extract::Extension;
 use axum::http::StatusCode;
@@ -12,45 +12,24 @@ use axum::Json;
 use mongodb::bson::doc;
 use serde::Deserialize;
 
-use compliance_core::models::onboarding::ComplianceFramework;
+use compliance_core::models::oscal_assessment::assess;
-use compliance_core::models::oscal_assessment::{assess, ControlLinker};
 use compliance_core::models::Finding;
 use compliance_core::tenant_ctx::TenantCtx;
 
 use super::dto::{collect_cursor_async, tenant_db, AgentExt};
-use crate::controls::OscalControlsProvider;
 
 #[derive(Debug, Deserialize)]
 pub struct AssessRequest {
     /// The target / repo id whose findings are assessed.
     pub target_id: String,
-    /// Frameworks to assess against; defaults to `[Cra]` when empty.
-    #[serde(default)]
-    pub frameworks: Vec<ComplianceFramework>,
 }
 
-/// `POST /api/v1/oscal/assess` — pull the catalog(s), load the target's findings,
+/// `POST /api/v1/oscal/assess` — OSCAL assessment-results for a target's findings.
-/// and emit an OSCAL assessment-results document linking findings to controls.
 pub async fn assess_target(
     Extension(agent): AgentExt,
     tenant: TenantCtx,
     Json(req): Json<AssessRequest>,
 ) -> Response {
-    let cfg = &agent.config.breakpilot;
-    let Some(base_url) = cfg.base_url.clone() else {
-        return (
-            StatusCode::SERVICE_UNAVAILABLE,
-            "breakpilot base URL not configured (set BREAKPILOT_BASE_URL)",
-        )
-            .into_response();
-    };
-
-    let frameworks = if req.frameworks.is_empty() {
-        vec![ComplianceFramework::Cra]
-    } else {
-        req.frameworks.clone()
-    };
-
     let db = match tenant_db(&agent, &tenant).await {
         Ok(db) => db,
         Err(code) => return code.into_response(),
@@ -65,25 +44,5 @@ pub async fn assess_target(
         }
     };
 
-    let provider = OscalControlsProvider::new(
+    Json(assess(&findings, chrono::Utc::now())).into_response()
-        agent.http.clone(),
-        base_url,
-        cfg.token.clone(),
-        &cfg.snapshot_dir,
-    );
-    let mut controls = Vec::new();
-    for framework in &frameworks {
-        match provider.load(*framework).await {
-            Ok(document) => controls.extend(document.to_controls()),
-            Err(e) => tracing::warn!(?framework, error = %e, "OSCAL catalog load failed"),
-        }
-    }
-
-    let assessment = assess(
-        &controls,
-        &findings,
-        &ControlLinker::cra_seed(),
-        chrono::Utc::now(),
-    );
-    Json(assessment).into_response()
 }

compliance-agent/src/config.rs

@@ -100,5 +100,8 @@ fn load_breakpilot_config() -> BreakpilotConfig {
         base_url: env_var_opt("BREAKPILOT_BASE_URL"),
         token: env_secret_opt("BREAKPILOT_TOKEN"),
         snapshot_dir: env_var_opt("BREAKPILOT_SNAPSHOT_DIR").unwrap_or(d.snapshot_dir),
+        semantic_mapping: env_var_opt("BREAKPILOT_SEMANTIC_MAPPING")
+            .map(|v| v == "1" || v.eq_ignore_ascii_case("true"))
+            .unwrap_or(d.semantic_mapping),
     }
 }

compliance-agent/src/controls/index.rs

@@ -0,0 +1,245 @@
+//! In-memory embedding index over the control corpus, for region → control
+//! retrieval.
+//!
+//! At master-control scale (~13.6k) findings can't be mapped by CWE (the master
+//! controls carry none), so we map by *similarity*: embed each control's
+//! requirement text once, then for a code region pull the top-K nearest controls
+//! to hand to the grounded judge. This is the retrieval half of the semantic path.
+
+use std::path::Path;
+
+use serde::{Deserialize, Serialize};
+use sha2::{Digest, Sha256};
+
+use compliance_core::control_check::ControlCheckSpec;
+use compliance_core::error::CoreError;
+
+use crate::llm::LlmClient;
+
+/// A control spec paired with its requirement-text embedding.
+pub struct ControlIndex {
+    entries: Vec<(ControlCheckSpec, Vec<f64>)>,
+}
+
+/// On-disk form of the index: the corpus identity hash plus every spec+embedding.
+/// The hash lets a later scan reuse the embeddings only if the corpus is unchanged.
+#[derive(Serialize, Deserialize)]
+struct PersistedIndex {
+    corpus_hash: String,
+    entries: Vec<PersistedEntry>,
+}
+
+#[derive(Serialize, Deserialize)]
+struct PersistedEntry {
+    spec: ControlCheckSpec,
+    embedding: Vec<f64>,
+}
+
+/// Stable hash of the corpus identity (each control's id + requirement text, in
+/// order). Same catalog → same hash → the cached embeddings are reused instead of
+/// re-embedding the whole corpus.
+fn corpus_hash(specs: &[ControlCheckSpec]) -> String {
+    let mut hasher = Sha256::new();
+    for s in specs {
+        hasher.update(s.control_id.as_bytes());
+        hasher.update([0u8]);
+        hasher.update(s.requirement.as_bytes());
+        hasher.update([0u8]);
+    }
+    format!("{:x}", hasher.finalize())
+}
+
+impl ControlIndex {
+    /// Build directly from precomputed embeddings (used by tests + callers that
+    /// already embedded the corpus).
+    pub fn from_embeddings(entries: Vec<(ControlCheckSpec, Vec<f64>)>) -> Self {
+        Self { entries }
+    }
+
+    /// Load the index from `cache_path` if it still matches the current corpus,
+    /// otherwise embed the corpus and persist it there. This turns the per-scan
+    /// re-embed of the whole (~13.6k) master-control corpus into a one-time cost
+    /// that survives across scans; the cache self-invalidates when the catalog
+    /// changes (its [`corpus_hash`] no longer matches).
+    pub async fn load_or_build(
+        llm: &LlmClient,
+        specs: Vec<ControlCheckSpec>,
+        cache_path: &Path,
+    ) -> Result<Self, CoreError> {
+        let hash = corpus_hash(&specs);
+        if let Some(index) = Self::load_cache(cache_path, &hash).await {
+            tracing::debug!(
+                controls = index.len(),
+                "reusing cached control embedding index"
+            );
+            return Ok(index);
+        }
+        let index = Self::build(llm, specs).await?;
+        if let Err(e) = index.write_cache(cache_path, &hash).await {
+            tracing::warn!(error = %e, "failed to persist control embedding index");
+        }
+        Ok(index)
+    }
+
+    /// Read a persisted index, returning it only if its corpus hash matches.
+    async fn load_cache(path: &Path, hash: &str) -> Option<Self> {
+        let raw = tokio::fs::read(path).await.ok()?;
+        let persisted: PersistedIndex = serde_json::from_slice(&raw).ok()?;
+        if persisted.corpus_hash != hash {
+            return None;
+        }
+        Some(Self {
+            entries: persisted
+                .entries
+                .into_iter()
+                .map(|e| (e.spec, e.embedding))
+                .collect(),
+        })
+    }
+
+    /// Persist the index atomically (temp file + rename) keyed by corpus hash.
+    async fn write_cache(&self, path: &Path, hash: &str) -> Result<(), CoreError> {
+        if let Some(parent) = path.parent() {
+            tokio::fs::create_dir_all(parent).await?;
+        }
+        let persisted = PersistedIndex {
+            corpus_hash: hash.to_string(),
+            entries: self
+                .entries
+                .iter()
+                .map(|(spec, emb)| PersistedEntry {
+                    spec: spec.clone(),
+                    embedding: emb.clone(),
+                })
+                .collect(),
+        };
+        let raw = serde_json::to_vec(&persisted)?;
+        let tmp = path.with_extension("json.tmp");
+        tokio::fs::write(&tmp, &raw).await?;
+        tokio::fs::rename(&tmp, path).await?;
+        Ok(())
+    }
+
+    /// Build by embedding each control's requirement text.
+    pub async fn build(llm: &LlmClient, specs: Vec<ControlCheckSpec>) -> Result<Self, CoreError> {
+        if specs.is_empty() {
+            return Ok(Self {
+                entries: Vec::new(),
+            });
+        }
+        let texts: Vec<String> = specs.iter().map(|s| s.requirement.clone()).collect();
+        let embeddings = llm
+            .embed(texts)
+            .await
+            .map_err(|e| CoreError::Llm(e.to_string()))?;
+        Ok(Self {
+            entries: specs.into_iter().zip(embeddings).collect(),
+        })
+    }
+
+    pub fn len(&self) -> usize {
+        self.entries.len()
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.entries.is_empty()
+    }
+
+    /// The top-`k` control specs whose embedding is nearest (cosine) to `query`.
+    pub fn nearest(&self, query: &[f64], k: usize) -> Vec<ControlCheckSpec> {
+        let mut scored: Vec<(f64, &ControlCheckSpec)> = self
+            .entries
+            .iter()
+            .map(|(spec, emb)| (cosine(query, emb), spec))
+            .collect();
+        scored.sort_by(|a, b| b.0.total_cmp(&a.0));
+        scored.into_iter().take(k).map(|(_, s)| s.clone()).collect()
+    }
+}
+
+/// Cosine similarity; 0.0 for length-mismatched, empty, or zero vectors.
+fn cosine(a: &[f64], b: &[f64]) -> f64 {
+    if a.len() != b.len() || a.is_empty() {
+        return 0.0;
+    }
+    let dot: f64 = a.iter().zip(b).map(|(x, y)| x * y).sum();
+    let na: f64 = a.iter().map(|x| x * x).sum();
+    let nb: f64 = b.iter().map(|x| x * x).sum();
+    if na == 0.0 || nb == 0.0 {
+        return 0.0;
+    }
+    dot / (na.sqrt() * nb.sqrt())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use compliance_core::models::finding::Severity;
+
+    fn spec(id: &str) -> ControlCheckSpec {
+        ControlCheckSpec {
+            control_id: id.into(),
+            title: id.into(),
+            requirement: id.into(),
+            default_cwe: None,
+            severity: Severity::Medium,
+        }
+    }
+
+    #[test]
+    fn nearest_ranks_by_cosine() {
+        let index = ControlIndex::from_embeddings(vec![
+            (spec("a"), vec![1.0, 0.0]),
+            (spec("b"), vec![0.0, 1.0]),
+            (spec("c"), vec![0.7, 0.7]),
+        ]);
+        let hits = index.nearest(&[0.9, 0.1], 2);
+        assert_eq!(hits.len(), 2);
+        assert_eq!(hits[0].control_id, "a"); // closest to [0.9,0.1]
+    }
+
+    #[test]
+    fn cosine_edges_are_zero() {
+        assert_eq!(cosine(&[1.0], &[1.0, 2.0]), 0.0); // length mismatch
+        assert_eq!(cosine(&[0.0, 0.0], &[1.0, 1.0]), 0.0); // zero vector
+        assert!((cosine(&[1.0, 0.0], &[1.0, 0.0]) - 1.0).abs() < 1e-9); // identical
+    }
+
+    #[test]
+    fn corpus_hash_is_stable_and_identity_sensitive() {
+        let a = corpus_hash(&[spec("x"), spec("y")]);
+        assert_eq!(a, corpus_hash(&[spec("x"), spec("y")])); // same corpus → same hash
+        assert_ne!(a, corpus_hash(&[spec("y"), spec("x")])); // reorder → different
+        assert_ne!(a, corpus_hash(&[spec("x")])); // fewer controls → different
+    }
+
+    #[tokio::test]
+    #[allow(clippy::unwrap_used)]
+    async fn cache_round_trips_and_misses_on_corpus_change() {
+        let dir = std::env::temp_dir().join(format!("cidx-{}", uuid::Uuid::new_v4()));
+        let path = dir.join("control-index.json");
+        let specs = [spec("a"), spec("b")];
+        let hash = corpus_hash(&specs);
+        let index = ControlIndex::from_embeddings(vec![
+            (spec("a"), vec![1.0, 0.0]),
+            (spec("b"), vec![0.0, 1.0]),
+        ]);
+        index.write_cache(&path, &hash).await.unwrap();
+
+        // matching corpus hash → hit
+        let loaded = ControlIndex::load_cache(&path, &hash).await.unwrap();
+        assert_eq!(loaded.len(), 2);
+        assert_eq!(loaded.nearest(&[0.9, 0.1], 1)[0].control_id, "a");
+        // corpus changed → miss (forces a rebuild)
+        assert!(ControlIndex::load_cache(&path, "differenthash")
+            .await
+            .is_none());
+        // absent file → miss, not an error
+        assert!(
+            ControlIndex::load_cache(dir.join("nope.json").as_path(), &hash)
+                .await
+                .is_none()
+        );
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+}

compliance-agent/src/controls/mod.rs

@@ -6,13 +6,17 @@
 //! and snapshots it locally.
 
 mod checker;
+mod index;
 mod judge;
 mod oscal_provider;
 mod scan_triage;
+mod semantic;
 mod triage;
 
 pub use checker::GroundedControlChecker;
+pub use index::ControlIndex;
 pub use judge::{ControlJudge, LlmControlJudge, PROMPT_VERSION};
 pub use oscal_provider::OscalControlsProvider;
-pub use scan_triage::triage_repo_findings;
+pub use scan_triage::{semantic_stamp_findings, triage_repo_findings};
+pub use semantic::SemanticControlChecker;
 pub use triage::{ControlTriage, TriageOutcome};

compliance-agent/src/controls/oscal_provider.rs

@@ -43,20 +43,20 @@ impl OscalControlsProvider {
         }
     }
 
-    fn catalog_url(&self, framework: ComplianceFramework) -> String {
+    fn catalog_url(&self, framework: &str) -> String {
         format!(
             "{}/api/compliance/v1/oscal/catalog?framework={framework}",
             self.base_url.trim_end_matches('/')
         )
     }
 
-    fn snapshot_path(&self, framework: ComplianceFramework) -> PathBuf {
+    fn snapshot_path(&self, framework: &str) -> PathBuf {
         self.snapshot_dir
             .join(format!("oscal-catalog-{framework}.json"))
     }
 
-    /// Fetch the raw catalog bytes for a framework over HTTP.
+    /// Fetch the raw catalog bytes for a framework token over HTTP.
-    async fn fetch_raw(&self, framework: ComplianceFramework) -> Result<Vec<u8>, CoreError> {
+    async fn fetch_raw(&self, framework: &str) -> Result<Vec<u8>, CoreError> {
         let mut req = self.http.get(self.catalog_url(framework));
         if let Some(token) = &self.token {
             req = req.bearer_auth(token.expose_secret());
@@ -78,11 +78,7 @@ impl OscalControlsProvider {
     }
 
     /// Write a catalog snapshot atomically (temp file + rename).
-    async fn write_snapshot(
+    async fn write_snapshot(&self, framework: &str, raw: &[u8]) -> Result<(), CoreError> {
-        &self,
-        framework: ComplianceFramework,
-        raw: &[u8],
-    ) -> Result<(), CoreError> {
         tokio::fs::create_dir_all(&self.snapshot_dir).await?;
         let path = self.snapshot_path(framework);
         let tmp = path.with_extension("json.tmp");
@@ -92,10 +88,7 @@ impl OscalControlsProvider {
     }
 
     /// Read a previously written snapshot, if one exists.
-    async fn read_snapshot(
+    async fn read_snapshot(&self, framework: &str) -> Result<Option<OscalDocument>, CoreError> {
-        &self,
-        framework: ComplianceFramework,
-    ) -> Result<Option<OscalDocument>, CoreError> {
         match tokio::fs::read(self.snapshot_path(framework)).await {
             Ok(raw) => Ok(Some(serde_json::from_slice(&raw)?)),
             Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(None),
@@ -103,21 +96,21 @@ impl OscalControlsProvider {
         }
     }
 
-    /// Load the catalog for a framework: fetch fresh + snapshot the exact bytes;
+    /// Load the catalog for a framework token: fetch fresh + snapshot the exact
-    /// on network failure, fall back to the last snapshot so scans still run.
+    /// bytes; on network failure, fall back to the last snapshot so scans run.
-    pub async fn load(&self, framework: ComplianceFramework) -> Result<OscalDocument, CoreError> {
+    async fn load_token(&self, framework: &str) -> Result<OscalDocument, CoreError> {
         match self.fetch_raw(framework).await {
             Ok(raw) => {
                 let doc: OscalDocument = serde_json::from_slice(&raw)?;
                 if let Err(e) = self.write_snapshot(framework, &raw).await {
-                    tracing::warn!(%framework, error = %e, "failed to write OSCAL snapshot");
+                    tracing::warn!(framework, error = %e, "failed to write OSCAL snapshot");
                 }
                 Ok(doc)
             }
             Err(fetch_err) => match self.read_snapshot(framework).await? {
                 Some(doc) => {
                     tracing::warn!(
-                        %framework, error = %fetch_err,
+                        framework, error = %fetch_err,
                         "OSCAL catalog fetch failed; falling back to snapshot"
                     );
                     Ok(doc)
@@ -126,6 +119,17 @@ impl OscalControlsProvider {
             },
         }
     }
+
+    /// Load the OSCAL catalog for a compliance framework.
+    pub async fn load(&self, framework: ComplianceFramework) -> Result<OscalDocument, CoreError> {
+        self.load_token(&framework.to_string()).await
+    }
+
+    /// Load the code-checkable master-controls catalog
+    /// (`?framework=master-controls`).
+    pub async fn load_master_controls(&self) -> Result<OscalDocument, CoreError> {
+        self.load_token("master-controls").await
+    }
 }
 
 /// Order controls whose title/text mention the query context first (stable), then
@@ -181,11 +185,11 @@ mod tests {
     fn builds_catalog_url_and_snapshot_path() {
         let p = provider(std::path::Path::new("/snap"));
         assert_eq!(
-            p.catalog_url(ComplianceFramework::Cra),
+            p.catalog_url("cra"),
             "http://unused/api/compliance/v1/oscal/catalog?framework=cra"
         );
         assert_eq!(
-            p.snapshot_path(ComplianceFramework::Cra),
+            p.snapshot_path("cra"),
             std::path::Path::new("/snap/oscal-catalog-cra.json")
         );
     }
@@ -213,19 +217,11 @@ mod tests {
     async fn snapshot_round_trip_and_offline_fallback() {
         let dir = std::env::temp_dir().join(format!("oscal-test-{}", uuid::Uuid::new_v4()));
         let p = provider(&dir);
-        assert!(p
+        assert!(p.read_snapshot("cra").await.unwrap().is_none());
-            .read_snapshot(ComplianceFramework::Cra)
+        p.write_snapshot("cra", MINI_CATALOG.as_bytes())
-            .await
-            .unwrap()
-            .is_none());
-        p.write_snapshot(ComplianceFramework::Cra, MINI_CATALOG.as_bytes())
             .await
             .unwrap();
-        let doc = p
+        let doc = p.read_snapshot("cra").await.unwrap().unwrap();
-            .read_snapshot(ComplianceFramework::Cra)
-            .await
-            .unwrap()
-            .unwrap();
         assert_eq!(doc.to_controls().len(), 1);
         assert_eq!(doc.framework(), Some(ComplianceFramework::Cra));
         let _ = std::fs::remove_dir_all(&dir);

compliance-agent/src/controls/scan_triage.rs

@@ -16,9 +16,15 @@ use compliance_core::models::onboarding::ComplianceFramework;
 use compliance_core::AgentConfig;
 use control_map::ControlMap;
 
-use super::{ControlTriage, LlmControlJudge, OscalControlsProvider, TriageOutcome};
+use super::{
+    ControlIndex, ControlTriage, LlmControlJudge, OscalControlsProvider, SemanticControlChecker,
+    TriageOutcome,
+};
 use crate::llm::LlmClient;
 
+/// Nearest master controls judged per code region in the semantic pass.
+const SEMANTIC_TOP_K: usize = 5;
+
 /// Lines of context to read on each side of a finding's line.
 const REGION_WINDOW: usize = 6;
 
@@ -116,6 +122,107 @@ fn fetch_region(repo_path: &Path, file: &str, line: u32) -> Option<CandidateRegi
     })
 }
 
+/// Master-controls **semantic** pass: for each finding's code region, retrieve the
+/// top-K nearest master controls by embedding, have the grounded judge confirm,
+/// and stamp the confirmed control ids onto the finding — the scale path for the
+/// ~13.6k master-control corpus (which has no CWE to LUT on). Returns the number
+/// of findings that gained a master-control ref.
+///
+/// Gated: the orchestrator runs this only when `breakpilot.semantic_mapping` is
+/// set (default off, flipped on once the master-controls catalog is live). The
+/// control embedding index is built once and cached to `snapshot_dir` keyed by
+/// corpus hash ([`ControlIndex::load_or_build`]), so only the first scan after a
+/// catalog change pays the embedding cost.
+pub async fn semantic_stamp_findings(
+    config: &AgentConfig,
+    llm: Arc<LlmClient>,
+    repo_path: &Path,
+    findings: &mut [Finding],
+) -> usize {
+    let Some(base_url) = config.breakpilot.base_url.clone() else {
+        return 0;
+    };
+    let provider = OscalControlsProvider::new(
+        reqwest::Client::new(),
+        base_url,
+        config.breakpilot.token.clone(),
+        &config.breakpilot.snapshot_dir,
+    );
+    let doc = match provider.load_master_controls().await {
+        Ok(d) => d,
+        Err(e) => {
+            tracing::warn!(error = %e, "master-controls catalog unavailable; skipping semantic pass");
+            return 0;
+        }
+    };
+    let specs: Vec<ControlCheckSpec> = doc
+        .to_controls()
+        .into_iter()
+        .map(|c| ControlCheckSpec {
+            control_id: c.id,
+            title: c.title,
+            requirement: c.text,
+            default_cwe: None,
+            severity: Severity::Medium,
+        })
+        .collect();
+    let cache_path =
+        Path::new(&config.breakpilot.snapshot_dir).join("control-index-master-controls.json");
+    let index = match ControlIndex::load_or_build(&llm, specs, &cache_path).await {
+        Ok(i) if !i.is_empty() => i,
+        Ok(_) => return 0,
+        Err(e) => {
+            tracing::warn!(error = %e, "failed to embed master-controls corpus");
+            return 0;
+        }
+    };
+    let checker = SemanticControlChecker::new(LlmControlJudge::new(llm.clone()));
+
+    let mut tagged = 0;
+    for finding in findings.iter_mut() {
+        if finding.status == FindingStatus::FalsePositive {
+            continue;
+        }
+        let (Some(file), Some(line)) = (finding.file_path.clone(), finding.line_number) else {
+            continue;
+        };
+        let Some(region) = fetch_region(repo_path, &file, line) else {
+            continue;
+        };
+        let region_emb = match llm.embed(vec![region.content.clone()]).await {
+            Ok(mut embs) => match embs.pop() {
+                Some(v) => v,
+                None => continue,
+            },
+            Err(e) => {
+                tracing::warn!(error = %e, "region embed failed; skipping finding");
+                continue;
+            }
+        };
+        let confirmed = checker
+            .check(
+                &index,
+                &region,
+                &region_emb,
+                SEMANTIC_TOP_K,
+                &finding.repo_id,
+            )
+            .await;
+        let before = finding.control_refs.len();
+        for f in confirmed {
+            for cref in f.control_refs {
+                if !finding.control_refs.contains(&cref) {
+                    finding.control_refs.push(cref);
+                }
+            }
+        }
+        if finding.control_refs.len() > before {
+            tagged += 1;
+        }
+    }
+    tagged
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

compliance-agent/src/controls/semantic.rs

@@ -0,0 +1,119 @@
+//! Semantic control mapping: retrieve the top-K controls nearest a code region,
+//! then confirm each with the grounded judge.
+//!
+//! The `region → controls` direction (vs. the CWE-LUT's `finding → control`) is
+//! what scales to the full master-control corpus: the LLM only ever judges a
+//! handful of retrieved candidates, and every surviving verdict is still anchored
+//! to real code by the grounding gate.
+
+use compliance_core::control_check::{ground, CandidateRegion};
+use compliance_core::models::Finding;
+
+use super::index::ControlIndex;
+use super::judge::ControlJudge;
+
+/// Retrieve → judge → ground, generic over the judge so tests use a stub.
+pub struct SemanticControlChecker<J> {
+    judge: J,
+}
+
+impl<J: ControlJudge> SemanticControlChecker<J> {
+    pub fn new(judge: J) -> Self {
+        Self { judge }
+    }
+
+    /// Map a code region to the controls it violates. `region_embedding` is the
+    /// region's embedding (the caller computes it via the LLM); the top-`k`
+    /// nearest controls in `index` are judged and grounded.
+    pub async fn check(
+        &self,
+        index: &ControlIndex,
+        region: &CandidateRegion,
+        region_embedding: &[f64],
+        k: usize,
+        repo_id: &str,
+    ) -> Vec<Finding> {
+        let candidates = index.nearest(region_embedding, k);
+        let mut findings = Vec::new();
+        for spec in &candidates {
+            let verdict = self.judge.judge(spec, region).await;
+            if let Some(finding) = ground(spec, region, &verdict, repo_id) {
+                findings.push(finding);
+            }
+        }
+        findings
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use compliance_core::control_check::{ControlCheckSpec, LlmVerdict};
+    use compliance_core::models::finding::Severity;
+
+    struct StubJudge {
+        verdict: LlmVerdict,
+    }
+    impl ControlJudge for StubJudge {
+        async fn judge(&self, _s: &ControlCheckSpec, _r: &CandidateRegion) -> LlmVerdict {
+            self.verdict.clone()
+        }
+    }
+
+    fn spec(id: &str) -> ControlCheckSpec {
+        ControlCheckSpec {
+            control_id: id.into(),
+            title: id.into(),
+            requirement: id.into(),
+            default_cwe: None,
+            severity: Severity::Medium,
+        }
+    }
+
+    #[tokio::test]
+    async fn retrieves_then_grounds_the_nearest_control() {
+        let index = ControlIndex::from_embeddings(vec![
+            (spec("mc-near"), vec![1.0, 0.0]),
+            (spec("mc-far"), vec![0.0, 1.0]),
+        ]);
+        let checker = SemanticControlChecker::new(StubJudge {
+            verdict: LlmVerdict {
+                violates: true,
+                snippet: "PASSWORD = \"admin\"".into(),
+                cwe: None,
+                confidence: 0.9,
+            },
+        });
+        let region = CandidateRegion {
+            file: "src/auth.py".into(),
+            start_line: 1,
+            content: "PASSWORD = \"admin\"\n".into(),
+        };
+        // Query embedding nearest to mc-near; k=1 → only mc-near is judged.
+        let findings = checker
+            .check(&index, &region, &[0.95, 0.05], 1, "repo")
+            .await;
+        assert_eq!(findings.len(), 1);
+        assert_eq!(findings[0].control_refs, vec!["mc-near".to_string()]);
+    }
+
+    #[tokio::test]
+    async fn ungrounded_verdict_is_dropped() {
+        let index = ControlIndex::from_embeddings(vec![(spec("mc-near"), vec![1.0, 0.0])]);
+        let checker = SemanticControlChecker::new(StubJudge {
+            verdict: LlmVerdict {
+                violates: true,
+                snippet: "not in the region".into(),
+                cwe: None,
+                confidence: 0.9,
+            },
+        });
+        let region = CandidateRegion {
+            file: "f".into(),
+            start_line: 1,
+            content: "real code\n".into(),
+        };
+        let findings = checker.check(&index, &region, &[1.0, 0.0], 1, "repo").await;
+        assert!(findings.is_empty());
+    }
+}

compliance-agent/src/pipeline/orchestrator.rs

@@ -230,6 +230,28 @@ impl PipelineOrchestrator {
             tracing::info!("[{repo_id}] Control triage tagged {tagged} findings with control refs");
         }
 
+        // Stage 5c: semantic control mapping — scale path for the master-controls
+        // corpus (no CWE to LUT on): embed each finding's region, retrieve the
+        // nearest master controls, grounded-judge, and stamp confirmed refs. Gated
+        // (default off) as the corpus embedding + per-finding judging is the heavy
+        // path; enabled once verified live against a deployed master-controls catalog.
+        if self.config.breakpilot.semantic_mapping {
+            self.update_phase(scan_run_id, "semantic_control_mapping")
+                .await;
+            let sem = crate::controls::semantic_stamp_findings(
+                &self.config,
+                self.llm.clone(),
+                &repo_path,
+                &mut all_findings,
+            )
+            .await;
+            if sem > 0 {
+                tracing::info!(
+                    "[{repo_id}] Semantic mapping tagged {sem} findings with master-control refs"
+                );
+            }
+        }
+
         // Dedup against existing findings and insert new ones
         let mut new_count = 0u32;
         let mut new_findings: Vec<Finding> = Vec::new();

compliance-core/src/config.rs

@@ -75,6 +75,11 @@ pub struct BreakpilotConfig {
     pub token: Option<SecretString>,
     /// Directory for catalog snapshots.
     pub snapshot_dir: String,
+    /// Enable the master-controls **semantic** mapping pass (embed regions,
+    /// retrieve nearest controls, grounded-judge). Off by default: it is the
+    /// scale path and stays gated until verified live against a deployed
+    /// master-controls catalog.
+    pub semantic_mapping: bool,
 }
 
 impl Default for BreakpilotConfig {
@@ -83,6 +88,7 @@ impl Default for BreakpilotConfig {
             base_url: None,
             token: None,
             snapshot_dir: "/data/compliance-scanner/oscal".to_string(),
+            semantic_mapping: false,
         }
     }
 }

compliance-core/src/control_check.rs

@@ -14,13 +14,14 @@
 //! The LLM supplies cross-language / cross-stack pattern recognition; this module
 //! supplies the determinism.
 
+use serde::{Deserialize, Serialize};
 use sha2::{Digest, Sha256};
 
 use crate::models::finding::{Finding, Severity};
 use crate::models::scan::ScanType;
 
 /// A control rendered as a check the LLM judges code against.
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct ControlCheckSpec {
     /// Stable control id, e.g. `"cra-ai-8"`.
     pub control_id: String,

compliance-core/src/models/oscal_assessment.rs

@@ -15,8 +15,7 @@ use chrono::{DateTime, Utc};
 use serde::Serialize;
 use uuid::Uuid;
 
-use crate::models::finding::Finding;
+use crate::models::finding::{Finding, FindingStatus};
-use crate::traits::Control;
 
 const OSCAL_VERSION: &str = "1.1.2";
 /// Same namespace as the catalog exporter, so ids are stable and correlatable.
@@ -83,22 +82,23 @@ impl ControlLinker {
     }
 }
 
-/// Assess `findings` against `controls`: link findings to control-ids and build a
+/// Build a standard OSCAL assessment-results document from `findings`, using each
-/// standard OSCAL assessment-results document. `at` is the assessment timestamp.
+/// finding's stamped `control_refs` for control linkage. EVERY non-false-positive
-pub fn assess(
+/// finding is emitted as an observation — mapped findings additionally produce a
-    controls: &[Control],
+/// per-control `not-satisfied` finding; **unmapped findings are reported as-is**
-    findings: &[Finding],
+/// (an observation carrying their CWE/tool/severity, with no control target) so
-    linker: &ControlLinker,
+/// nothing is lost. `at` is the assessment timestamp.
-    at: DateTime<Utc>,
+pub fn assess(findings: &[Finding], at: DateTime<Utc>) -> AssessmentResultsDoc {
-) -> AssessmentResultsDoc {
     let ts = at.to_rfc3339();
 
     let mut observations = Vec::new();
     let mut obs_by_control: HashMap<String, Vec<String>> = HashMap::new();
+    let mut mapped = 0usize;
+    let mut unmapped = 0usize;
+
     for finding in findings {
-        let targets = linker.controls_for(finding);
+        if finding.status == FindingStatus::FalsePositive {
-        if targets.is_empty() {
+            continue; // flagged tool false positive — excluded from the report
-            continue;
         }
         let obs_uuid = det_uuid(&format!("obs:{}", finding.fingerprint));
         let location = match (&finding.file_path, finding.line_number) {
@@ -106,58 +106,67 @@ pub fn assess(
             (Some(f), None) => Some(f.clone()),
             _ => None,
         };
+        let is_mapped = !finding.control_refs.is_empty();
+        if is_mapped {
+            mapped += 1;
+        } else {
+            unmapped += 1;
+        }
+        let mut props = vec![
+            ObsProp::new("tool", &finding.scanner),
+            ObsProp::new("severity", &finding.severity.to_string()),
+            ObsProp::new("mapping", if is_mapped { "mapped" } else { "unmapped" }),
+        ];
+        if let Some(cwe) = &finding.cwe {
+            props.push(ObsProp::new("cwe", cwe));
+        }
         observations.push(Observation {
             uuid: obs_uuid.clone(),
-            description: finding.title.clone(),
+            title: finding.title.clone(),
+            description: finding.description.clone(),
             methods: vec!["TEST".to_string()],
             collected: ts.clone(),
+            props,
             relevant_evidence: vec![RelevantEvidence {
                 href: location.map(|l| format!("file://{l}")),
                 description: format!("[{}] {}", finding.scanner, finding.title),
             }],
         });
-        for control_id in targets {
+        for control_id in &finding.control_refs {
             obs_by_control
-                .entry(control_id)
+                .entry(control_id.clone())
                 .or_default()
                 .push(obs_uuid.clone());
         }
     }
 
-    let titles: HashMap<&str, &str> = controls
-        .iter()
-        .map(|c| (c.id.as_str(), c.title.as_str()))
-        .collect();
     let mut hit_controls: Vec<&String> = obs_by_control.keys().collect();
     hit_controls.sort();
     let ar_findings: Vec<ArFinding> = hit_controls
-        .into_iter()
+        .iter()
-        .map(|control_id| {
+        .map(|control_id| ArFinding {
-            let title = titles.get(control_id.as_str()).copied().unwrap_or("");
+            uuid: det_uuid(&format!("finding:{control_id}")),
-            ArFinding {
+            title: format!("Findings affect {control_id}"),
-                uuid: det_uuid(&format!("finding:{control_id}")),
+            target: FindingTarget {
-                title: format!("Findings affect {control_id}: {title}"),
+                target_type: "statement-id".to_string(),
-                target: FindingTarget {
+                target_id: format!("{control_id}_smt"),
-                    target_type: "statement-id".to_string(),
+                status: TargetStatus {
-                    target_id: format!("{control_id}_smt"),
+                    state: "not-satisfied".to_string(),
-                    status: TargetStatus {
-                        state: "not-satisfied".to_string(),
-                    },
                 },
-                related_observations: obs_by_control[control_id]
+            },
-                    .iter()
+            related_observations: obs_by_control[*control_id]
-                    .map(|u| RelatedObservation {
+                .iter()
-                        observation_uuid: u.clone(),
+                .map(|u| RelatedObservation {
-                    })
+                    observation_uuid: u.clone(),
-                    .collect(),
+                })
-            }
+                .collect(),
         })
         .collect();
 
-    let include_controls = controls
+    let include_controls: Vec<SelectControlById> = hit_controls
         .iter()
         .map(|c| SelectControlById {
-            control_id: c.id.clone(),
+            control_id: (*c).clone(),
         })
         .collect();
 
@@ -165,9 +174,9 @@ pub fn assess(
         uuid: det_uuid("result:cra"),
         title: "Automated code-compliance assessment".to_string(),
         description: format!(
-            "{} finding-linked observation(s) across {} reviewed control(s)",
+            "{} observation(s): {mapped} control-linked, {unmapped} unmapped (as-is); {} control(s) affected",
             observations.len(),
-            controls.len()
+            include_controls.len()
         ),
         start: ts.clone(),
         reviewed_controls: ReviewedControls {
@@ -262,13 +271,33 @@ pub struct SelectControlById {
 #[derive(Debug, Clone, Serialize)]
 pub struct Observation {
     pub uuid: String,
+    pub title: String,
     pub description: String,
     pub methods: Vec<String>,
     pub collected: String,
+    #[serde(skip_serializing_if = "Vec::is_empty")]
+    pub props: Vec<ObsProp>,
     #[serde(rename = "relevant-evidence", skip_serializing_if = "Vec::is_empty")]
     pub relevant_evidence: Vec<RelevantEvidence>,
 }
 
+/// A name/value observation property (cwe, tool, severity, mapping status). Lets an
+/// unmapped finding be reported fully as-is.
+#[derive(Debug, Clone, Serialize)]
+pub struct ObsProp {
+    pub name: String,
+    pub value: String,
+}
+
+impl ObsProp {
+    fn new(name: &str, value: &str) -> Self {
+        Self {
+            name: name.to_string(),
+            value: value.to_string(),
+        }
+    }
+}
+
 #[derive(Debug, Clone, Serialize)]
 pub struct RelevantEvidence {
     #[serde(skip_serializing_if = "Option::is_none")]
@@ -310,20 +339,9 @@ pub struct RelatedObservation {
 mod tests {
     use super::*;
     use crate::models::finding::Severity;
-    use crate::models::onboarding::ComplianceFramework;
     use crate::models::scan::ScanType;
 
-    fn control(id: &str, title: &str) -> Control {
+    fn finding(fp: &str, cwe: Option<&str>, refs: &[&str]) -> Finding {
-        Control {
-            id: id.into(),
-            framework: ComplianceFramework::Cra,
-            title: title.into(),
-            text: String::new(),
-            source: None,
-        }
-    }
-
-    fn finding(fp: &str, cwe: Option<&str>) -> Finding {
         let mut f = Finding::new(
             "repo".into(),
             fp.into(),
@@ -336,6 +354,7 @@ mod tests {
         f.cwe = cwe.map(Into::into);
         f.file_path = Some("src/auth.rs".into());
         f.line_number = Some(42);
+        f.control_refs = refs.iter().map(|s| s.to_string()).collect();
         f
     }
 
@@ -346,57 +365,60 @@ mod tests {
     }
 
     #[test]
-    fn links_cwe_finding_to_control_not_satisfied() {
+    fn mapped_finding_becomes_control_finding() {
-        let controls = vec![
+        let doc = assess(&[finding("f1", Some("CWE-798"), &["cra-ai-8"])], at());
-            control("cra-ai-8", "No default passwords"),
-            control("cra-ai-13", "Crypto"),
-        ];
-        let findings = vec![finding("f1", Some("CWE-798"))];
-        let doc = assess(&controls, &findings, &ControlLinker::cra_seed(), at());
         let r = &doc.assessment_results.results[0];
         assert_eq!(r.observations.len(), 1);
         assert_eq!(r.findings.len(), 1);
         assert_eq!(r.findings[0].target.target_id, "cra-ai-8_smt");
         assert_eq!(r.findings[0].target.status.state, "not-satisfied");
-        assert_eq!(r.findings[0].related_observations.len(), 1);
         assert_eq!(
             r.reviewed_controls.control_selections[0]
                 .include_controls
                 .len(),
-            2
+            1
         );
     }
 
     #[test]
-    fn unlinked_finding_yields_no_control_finding() {
+    fn unmapped_finding_is_reported_as_is() {
-        let controls = vec![control("cra-ai-8", "x")];
+        let doc = assess(&[finding("f1", Some("CWE-319"), &[])], at());
-        let findings = vec![finding("f1", Some("CWE-99999"))];
-        let doc = assess(&controls, &findings, &ControlLinker::cra_seed(), at());
         let r = &doc.assessment_results.results[0];
-        assert!(r.observations.is_empty());
+        assert_eq!(r.observations.len(), 1); // still emitted...
-        assert!(r.findings.is_empty());
+        assert!(r.findings.is_empty()); // ...but no control finding
+        assert!(r.reviewed_controls.control_selections[0]
+            .include_controls
+            .is_empty());
+        let props: Vec<(&str, &str)> = r.observations[0]
+            .props
+            .iter()
+            .map(|p| (p.name.as_str(), p.value.as_str()))
+            .collect();
+        assert!(props.contains(&("mapping", "unmapped")));
+        assert!(props.contains(&("cwe", "CWE-319")));
     }
 
     #[test]
-    fn output_is_deterministic_and_valid_oscal() {
+    fn false_positive_is_excluded() {
-        let controls = vec![control("cra-ai-8", "x")];
+        let mut f = finding("f1", Some("CWE-798"), &["cra-ai-8"]);
-        let findings = vec![finding("f1", Some("798"))];
+        f.status = FindingStatus::FalsePositive;
-        let a = serde_json::to_string(&assess(
+        let doc = assess(&[f], at());
-            &controls,
+        assert!(doc.assessment_results.results[0].observations.is_empty());
-            &findings,
+    }
-            &ControlLinker::cra_seed(),
+
-            at(),
+    #[test]
-        ))
+    fn deterministic_and_valid_oscal() {
-        .unwrap();
+        let mk = || {
-        let b = serde_json::to_string(&assess(
+            vec![
-            &controls,
+                finding("f1", Some("CWE-798"), &["cra-ai-8"]),
-            &findings,
+                finding("f2", Some("CWE-319"), &[]),
-            &ControlLinker::cra_seed(),
+            ]
-            at(),
+        };
-        ))
+        let a = serde_json::to_string(&assess(&mk(), at())).unwrap();
-        .unwrap();
+        let b = serde_json::to_string(&assess(&mk(), at())).unwrap();
         assert_eq!(a, b);
         assert!(a.contains("\"oscal-version\":\"1.1.2\""));
         assert!(a.contains("\"not-satisfied\""));
+        assert!(a.contains("\"mapping\""));
     }
 }

compliance-mcp/src/server.rs

@@ -4,7 +4,7 @@ use rmcp::{
 
 use crate::auth::current_tenant_id;
 use crate::database::{Database, DatabasePool};
-use crate::tools::{dast, findings, pentest, sbom};
+use crate::tools::{dast, findings, oscal, pentest, sbom};
 
 pub struct ComplianceMcpServer {
     pool: DatabasePool,
@@ -68,6 +68,17 @@ impl ComplianceMcpServer {
         findings::findings_summary(&db, params).await
     }
 
+    #[tool(
+        description = "Emit an OSCAL 1.1 assessment-results document for a repo's findings (mapped findings target their compliance controls; unmapped findings are reported as-is)"
+    )]
+    async fn oscal_assessment(
+        &self,
+        Parameters(params): Parameters<oscal::OscalAssessmentParams>,
+    ) -> Result<CallToolResult, rmcp::ErrorData> {
+        let db = self.tenant_db()?;
+        oscal::oscal_assessment(&db, params).await
+    }
+
     // ── SBOM ──────────────────────────────────────────────
 
     #[tool(

compliance-mcp/src/tools/mod.rs

@@ -1,4 +1,5 @@
 pub mod dast;
 pub mod findings;
+pub mod oscal;
 pub mod pentest;
 pub mod sbom;

compliance-mcp/src/tools/oscal.rs

@@ -0,0 +1,51 @@
+//! OSCAL assessment MCP tool.
+//!
+//! Emits a standard OSCAL assessment-results document for a repo's findings —
+//! what breakpilot's scanner MCP client pulls. Mapped findings target their
+//! compliance controls (via the stamped `control_refs`); unmapped findings are
+//! reported as-is, so nothing is lost.
+
+use mongodb::bson::doc;
+use rmcp::{model::*, ErrorData as McpError};
+use schemars::JsonSchema;
+use serde::Deserialize;
+
+use compliance_core::models::oscal_assessment::assess;
+use compliance_core::models::Finding;
+
+use crate::database::Database;
+
+#[derive(Debug, Deserialize, JsonSchema)]
+pub struct OscalAssessmentParams {
+    /// Repository / target id to assess.
+    pub repo_id: String,
+}
+
+pub async fn oscal_assessment(
+    db: &Database,
+    params: OscalAssessmentParams,
+) -> Result<CallToolResult, McpError> {
+    let mut cursor = db
+        .findings()
+        .find(doc! { "repo_id": &params.repo_id })
+        .await
+        .map_err(|e| McpError::internal_error(format!("DB error: {e}"), None))?;
+
+    let mut findings: Vec<Finding> = Vec::new();
+    while cursor
+        .advance()
+        .await
+        .map_err(|e| McpError::internal_error(format!("cursor error: {e}"), None))?
+    {
+        findings.push(
+            cursor
+                .deserialize_current()
+                .map_err(|e| McpError::internal_error(format!("deserialize error: {e}"), None))?,
+        );
+    }
+
+    let document = assess(&findings, chrono::Utc::now());
+    let json = serde_json::to_string_pretty(&document)
+        .map_err(|e| McpError::internal_error(format!("json error: {e}"), None))?;
+    Ok(CallToolResult::success(vec![Content::text(json)]))
+}