fix(extraction): index TypeScript interface members (#1638) (#1780)

Land upstream #1686 (maxmilian + bompus kernel/CG-28 follow-ups)
onto current main. tree-sitter-typescript interface members
(method_signature / property_signature) were never listed in the
TS extractor, so platform .d.ts APIs had no declaration nodes for
call edges. Mirrors on the Rust kernel path; keeps CG-28 damping
for pure-interface declaration files; filters damped files from
the explore RWR seed set.

Co-authored-by: Colby McHenry <colbymchenry@users.noreply.github.com>

CHANGELOG.md

@@ -213,6 +213,7 @@ and adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 #### Symbols, tests and the viewer
 
+- TypeScript interface methods and properties are now indexed, so `node`, `callers` and impact can find platform `.d.ts` APIs while declaration-only files keep their lower ranking on flow queries; re-index TypeScript projects after upgrading. (#1638)
 - Lua and Luau function expressions assigned to locals, table members, or keyed table fields are now indexed as callable nodes. Calls from `local f = function() ... end`, `M.f = function() ... end`, and callback tables such as `M.handlers = { onClick = function() ... end }` are attributed to the named function or method instead of collapsing onto the file node, so callers and impact no longer omit these handlers. Re-index after upgrading. (#1616, #1650)
 - **Functions bound with `const` inside another function are symbols now.** `const handleClear = () => {…}` inside a React component — every handler that skips `useCallback` — was invisible to `callers`, `callees` and impact, answering "Symbol not found" exactly the way a function with no callers would. It is indexed like its module-level twin, contained by the enclosing function, with its own calls. Re-index after upgrading. (#1669)
 - `codegraph callers`, `callees`, and `query` now clearly report when their result limit hides additional matches, including exact totals in callers/callees JSON output; the `codegraph_callers` and `codegraph_callees` MCP answers carry the same "showing N of M" note. (#1639, #1674)

__tests__/explore-declaration-only.test.ts

@@ -96,15 +96,36 @@ describe('CG-28 — a declaration-only file does not outrank implementation on a
     if (testDir && fs.existsSync(testDir)) fs.rmSync(testDir, { recursive: true, force: true });
   });
 
+  /**
+   * Type-level for the purposes of this gate: a type declaration, or a member
+   * an interface declares.
+   *
+   * The second half is not a loosening. Since #1638 a `method_signature` /
+   * `property_signature` is indexed as a `method` / `property` node, so a file
+   * of nothing but interfaces no longer reads as nothing but `interface` kinds
+   * — but a bodiless signature is on the same side of the line as the interface
+   * that owns it, which is exactly how `getAmbientDeclarationPathsAmong` counts
+   * it. What this still catches, and is here to catch, is a `function` or a
+   * `class` creeping into the fixture: that would silently exempt the file and
+   * make every assertion below vacuous.
+   */
+  const isTypeLevel = (n: { id: string; kind: string }, filePath: string): boolean => {
+    if (n.kind === 'interface' || n.kind === 'type_alias') return true;
+    if (n.kind !== 'method' && n.kind !== 'property') return false;
+    const interfaceIds = new Set(
+      cg.getNodesInFile(filePath).filter((x) => x.kind === 'interface').map((x) => x.id),
+    );
+    return cg.getIncomingEdges(n.id)
+      .some((e) => e.kind === 'contains' && interfaceIds.has(e.source));
+  };
+
   describe('fixture shape — if this rots, the gate below means nothing', () => {
     it('holds two declaration-only files that differ only in the banner', () => {
       for (const p of [HANDWRITTEN_DECL, GENERATED_DECL]) {
         const nodes = cg.getNodesInFile(p).filter((n) => n.kind !== 'file' && n.kind !== 'import');
         expect(nodes.length, `${p} declares nothing`).toBeGreaterThan(10);
-        // Every symbol type-level, nothing with a body — the structural test the
-        // penalty keys on. A `function`/`class` creeping in would silently exempt
-        // the file and make every assertion below vacuous.
-        expect(nodes.every((n) => n.kind === 'interface' || n.kind === 'type_alias'), `${p} has a non-type symbol`).toBe(true);
+        // Nothing with a body — the structural test the penalty keys on.
+        expect(nodes.every((n) => isTypeLevel(n, p)), `${p} has a non-type symbol`).toBe(true);
       }
       // Only one of them announces itself, so the CG-25 penalty is the ONLY
       // difference between the two — that is what makes them comparable.
@@ -119,7 +140,7 @@ describe('CG-28 — a declaration-only file does not outrank implementation on a
       // structure of any answer about that code.
       const nodes = cg.getNodesInFile(SHARED_TYPES).filter((n) => n.kind !== 'file' && n.kind !== 'import');
       expect(nodes.length).toBeGreaterThan(0);
-      expect(nodes.every((n) => n.kind === 'interface' || n.kind === 'type_alias')).toBe(true);
+      expect(nodes.every((n) => isTypeLevel(n, SHARED_TYPES))).toBe(true);
       expect(cg.getFile(SHARED_TYPES)?.generated).toBeFalsy();
     });
 
@@ -176,6 +197,23 @@ describe('CG-28 — a declaration-only file does not outrank implementation on a
       expect(isAmbient(SHARED_TYPES)).toBe(false);
       expect(isAmbient(HANDWRITTEN_DECL)).toBe(true);
     });
+
+    it('still flags a shim whose interfaces now contribute method/property nodes', () => {
+      // The silent-failure guard for #1638. Interface members are indexed, so a
+      // pure-interface `.d.ts` no longer holds only `interface` kinds — and the
+      // ambient rule is spelled as "EVERY declared symbol is type-level". Read
+      // literally that stops flagging the moment the extractor improves, and
+      // nothing else fails: the file just quietly ranks undamped again.
+      //
+      // Pinned from both ends on purpose. The `toBeGreaterThan(0)` half is what
+      // keeps the other half honest — assert only the flag and this test would
+      // still pass on an index where the members were never extracted at all,
+      // which is precisely the state it exists to detect a regression FROM.
+      const members = cg.getNodesInFile(HANDWRITTEN_DECL)
+        .filter((n) => n.kind === 'method' || n.kind === 'property');
+      expect(members.length, 'interface members are not indexed — see #1638').toBeGreaterThan(0);
+      expect(cg.ambientDeclarationFilePredicate([HANDWRITTEN_DECL])(HANDWRITTEN_DECL)).toBe(true);
+    });
   });
 
   describe('the counter-case — a query that NAMES a declared type', () => {

__tests__/extraction.test.ts

@@ -566,6 +566,55 @@ interface Hprops {
     expect(refs.some((r) => r.referenceName === 'IOrderField')).toBe(true);
   });
 
+  it('indexes interface members, not just the interface itself', () => {
+    // tree-sitter-typescript spells interface members `method_signature` /
+    // `property_signature`, distinct from the class-member types the extractor
+    // listed, so they were never captured (#1638). Java/C# are unaffected —
+    // their grammars reuse `method_declaration`, already in their methodTypes.
+    // The cost lands on `.d.ts` platform APIs: with no declaration node, call
+    // sites through the interface have nothing to attach an edge to.
+    const code = `
+export interface PlatformApi {
+  fetchPage(id: string): Promise<string>;
+  version: string;
+}
+`;
+    const result = extractFromSource('api.d.ts', code);
+
+    const iface = result.nodes.find((n) => n.kind === 'interface' && n.name === 'PlatformApi');
+    const method = result.nodes.find((n) => n.kind === 'method' && n.name === 'fetchPage');
+    const prop = result.nodes.find((n) => n.kind === 'property' && n.name === 'version');
+    expect(iface).toBeDefined();
+    expect(method).toBeDefined();
+    expect(prop).toBeDefined();
+
+    // Attached to the interface, not merely present. A member the graph holds
+    // but hangs off the file is not a declaration a call edge can be resolved
+    // through, which is the whole point of extracting it.
+    const contained = result.edges
+      .filter((e) => e.kind === 'contains' && e.source === iface!.id)
+      .map((e) => e.target);
+    expect(contained).toContain(method!.id);
+    expect(contained).toContain(prop!.id);
+  });
+
+  it('does not mint a top-level function from a type literal method signature', () => {
+    // The failure mode the class-like guard on `method_signature` exists for
+    // (#1638). `extractMethod` treats a method node with no class-like parent
+    // as a free function — right for `method_definition`, wrong for a bodiless
+    // signature, whose only home outside an interface is a type literal. Those
+    // members are already extracted onto the alias (#359), so without the guard
+    // the file gains a phantom `function stop` beside the real `Handle::stop`.
+    const result = extractFromSource('t.ts', `
+export type Handle = { stop(): void; label: string };
+`);
+
+    const alias = result.nodes.find((n) => n.kind === 'type_alias' && n.name === 'Handle');
+    expect(alias).toBeDefined();
+    expect(result.nodes.find((n) => n.kind === 'method' && n.name === 'stop')).toBeDefined();
+    expect(result.nodes.filter((n) => n.kind === 'function' && n.name === 'stop')).toEqual([]);
+  });
+
   it('should extract type references from interface method signatures', () => {
     const code = `
 import type { IPage } from '../PromoterList';
@@ -899,10 +948,20 @@ export type Names = ['alpha', 'beta'];
 `;
     const result = extractFromSource('noise.ts', code);
 
+    // Since #1638 the fixture's own interfaces legitimately declare `id` / `name`
+    // (`User::id`, `User::name`, `Service::name`), so membership in the name list
+    // no longer implies a leak. What #634 guards is the *source*: a node minted
+    // from a string literal in `Pick<User, 'id'>` or a tuple has no declaring
+    // interface, so exclude anything a `contains` edge ties to one.
+    const ifaceIds = new Set(result.nodes.filter((n) => n.kind === 'interface').map((n) => n.id));
+    const declaredInInterface = new Set(
+      result.edges.filter((e) => e.kind === 'contains' && ifaceIds.has(e.source)).map((e) => e.target)
+    );
     const leaked = result.nodes.filter(
       (n) =>
         (n.kind === 'method' || n.kind === 'property') &&
-        ['id', 'name', 'foo', 'bar', 'alpha', 'beta'].includes(n.name)
+        ['id', 'name', 'foo', 'bar', 'alpha', 'beta'].includes(n.name) &&
+        !declaredInInterface.has(n.id)
     );
     expect(leaked).toEqual([]);
   });

__tests__/object-literal-methods.test.ts

@@ -53,7 +53,11 @@ describe('object-literal method extraction', () => {
 
     // Each action's body was walked: fetchUser references its sibling `reset`,
     // so an in-store calls edge will resolve once the pipeline runs.
-    const fetchUser = result.nodes.find((n) => n.name === 'fetchUser')!;
+    // By KIND as well as name: the fixture's `Store` interface declares a
+    // `fetchUser` too, and since #1638 that signature is a node of its own —
+    // one that appears FIRST in the file, so a name-only lookup finds the
+    // declaration and reads its return type where the action's body was meant.
+    const fetchUser = result.nodes.find((n) => n.kind === 'function' && n.name === 'fetchUser')!;
     const fetchUserRefs = result.unresolvedReferences.filter((r) => r.fromNodeId === fetchUser.id);
     // `get().reset()` keeps its call receiver (#1683): the ref is the chain
     // `get().reset`, which the resolver binds to the store's own `reset`.

codegraph-kernel/src/tsjs/extractors.rs

@@ -302,8 +302,33 @@ impl<'t> Walker<'t> {
         let name = self.text(name_node).to_string();
 
         // TS/JS field definitions carry an explicit `type` field; the generic
-        // scan is for other languages (#808).
-        let type_text = node.child_by_field_name("type").map(|t| {
+        // scan is for other languages (#808). A `property_signature` (an
+        // interface member, #1638) carries a `type` field and no value, so it
+        // reads the type field too: the generic scan's exclusion list covers
+        // `identifier` but not the `property_identifier` an interface member is
+        // named with, so it would stop on the name and make the signature repeat
+        // it (`counts counts`) instead of naming the type. Mirrors
+        // extractProperty's isTsJsField.
+        let is_ts_js_field = matches!(
+            node.kind(),
+            "public_field_definition" | "field_definition" | "property_signature"
+        );
+        let type_node = if is_ts_js_field {
+            node.child_by_field_name("type")
+        } else {
+            (0..node.named_child_count()).filter_map(|i| node.named_child(i)).find(|c| {
+                !matches!(
+                    c.kind(),
+                    "modifier"
+                        | "modifiers"
+                        | "identifier"
+                        | "accessor_list"
+                        | "accessors"
+                        | "equals_value_clause"
+                )
+            })
+        };
+        let type_text = type_node.map(|t| {
             let raw = self.text(t);
             raw.strip_prefix(':').unwrap_or(raw).trim_start().to_string()
         });

codegraph-kernel/src/tsjs/mod.rs

@@ -55,10 +55,32 @@ impl Variant {
 /// typescriptExtractor.methodTypes / javascriptExtractor.methodTypes.
 fn is_method_type(v: Variant, kind: &str) -> bool {
     kind == "method_definition"
-        || (v.is_ts() && kind == "public_field_definition")
+        || (v.is_ts() && matches!(kind, "public_field_definition" | "method_signature"))
         || (!v.is_ts() && kind == "field_definition")
 }
 
+/// typescriptExtractor.propertyTypes. The interface counterpart of
+/// `public_field_definition`: it carries no value, so it is always a property
+/// and never goes through classify_ts_class_member (#1638).
+fn is_property_type(v: Variant, kind: &str) -> bool {
+    v.is_ts() && kind == "property_signature"
+}
+
+/// Method node types that spell a SIGNATURE — a declaration with no body (#1638).
+///
+/// They are a method of whatever type declares them and nothing on their own, so
+/// they must not take `extract_method`'s "no class-like parent, so treat it as a
+/// free function" fallback. The other method types can: a `method_definition`
+/// outside a class really is a function. This one appears outside a class only
+/// inside a type literal (`type Handle = { stop(): void }`), whose members
+/// `extract_ts_type_alias_members` already extracts and attaches to the alias
+/// (#359) — take the fallback and the file gains a phantom top-level
+/// `function stop` beside the real `Handle::stop`. Mirrors the TS extractor's
+/// SIGNATURE_METHOD_NODE_TYPES (extraction/tree-sitter.ts).
+fn is_signature_method_type(kind: &str) -> bool {
+    kind == "method_signature"
+}
+
 fn is_function_type(kind: &str) -> bool {
     matches!(kind, "function_declaration" | "generator_function_declaration" | "arrow_function" | "function_expression" | "generator_function")
 }
@@ -622,7 +644,9 @@ impl<'t> Walker<'t> {
         } else if is_class_type(self.variant, kind) {
             self.extract_class(node);
             skip_children = true;
-        } else if is_method_type(self.variant, kind) {
+        } else if is_method_type(self.variant, kind)
+            && (!is_signature_method_type(kind) || self.inside_class_like())
+        {
             if classify_ts_class_member(node) == Member::Property {
                 let prop = self.extract_property(node);
                 if let (Some((row, name)), Some(value)) = (prop, node.child_by_field_name("value")) {
@@ -664,12 +688,22 @@ impl<'t> Walker<'t> {
             self.extract_call(node);
         } else if kind == "new_expression" {
             self.extract_instantiation(node);
-        } else if self.variant.is_ts()
-            && matches!(kind, "property_signature" | "method_signature")
-            && self.inside_class_like()
-        {
-            let parent = self.top_row();
-            self.extract_type_annotations(node, parent);
+        } else if is_property_type(self.variant, kind) && self.inside_class_like() {
+            // NOTE: `property_signature` / `method_signature` used to be handled
+            // here together, hanging their type annotations off the ENCLOSING
+            // INTERFACE — the only anchor available while the members themselves
+            // went unextracted. Since #1638 `method_signature` is a method type
+            // and `property_signature` a property type, so the method branch
+            // above claims the first (under the same inside_class_like guard
+            // this branch had) and this one extracts the second as a real node.
+            // The `references` edges survive — extract_method and
+            // extract_property each call extract_type_annotations — but now hang
+            // off the member, the more precise anchor: `Api::fetch → PageId`
+            // says which member wants the type, where `Api → PageId` only said
+            // the file did.
+            self.extract_property(node);
+            self.scan_fn_ref_subtree(node, 0);
+            skip_children = true;
         }
 
         if !skip_children {

src/db/queries.ts

@@ -55,6 +55,24 @@ function isLowValueFile(filePath: string, generated?: ReadonlySet<string>): bool
 
 const SQLITE_PARAM_CHUNK_SIZE = 500;
 
+/**
+ * A SQL predicate: is the node aliased `alias` a member an INTERFACE declares?
+ *
+ * `method_signature` / `property_signature` enter the graph as `method` /
+ * `property` nodes hung off their interface by a `contains` edge (#1638). They
+ * have no body and originate no behaviour, so for a structural judgement about
+ * a FILE they are the interface restated, not an extra thing the file declares.
+ * See {@link QueryBuilder.getAmbientDeclarationPathsAmong}, the one caller, for
+ * why treating them as opaque would break that rule in three places at once.
+ *
+ * Seeks `idx_edges_target_kind`, so it costs a key lookup per row rather than a
+ * join over the whole edge table.
+ */
+const IS_INTERFACE_MEMBER = (alias: string): string => `EXISTS (
+  SELECT 1 FROM edges ce JOIN nodes owner ON owner.id = ce.source
+   WHERE ce.target = ${alias}.id AND ce.kind = 'contains' AND owner.kind = 'interface'
+)`;
+
 /**
  * How much of the exact-name bonus a `deprioritize`d path keeps (#982). Damped
  * rather than zeroed: a query that genuinely targets that tree must still rank
@@ -2736,6 +2754,29 @@ export class QueryBuilder {
    *      restricted to the candidate list: the file that imports it is usually
    *      not itself a candidate.
    *
+   * ### Interface MEMBERS are transparent to all four conditions
+   *
+   * A `method_signature` / `property_signature` inside an interface enters the
+   * graph as a `method` / `property` node (#1638). Read literally that would
+   * break every condition here at once: condition 2 sees non-type kinds and
+   * stops flagging, and — worse, because it is silent — condition 4 starts
+   * seeing inbound `calls` edges the moment a call site through the shim's API
+   * finally has a signature to land on. An ambient `.d.ts` would quietly lose
+   * its damping precisely BECAUSE the platform API it declares is widely used.
+   *
+   * So an interface-owned member is treated the way `parameter` already is: it
+   * neither qualifies, disqualifies, nor counts as inbound dependency. That is
+   * not a new judgement call, it is what keeps the rule measuring what it was
+   * measured on — before #1638 these nodes did not exist, so excluding them
+   * reproduces the 0–4% flag rate the thresholds above were tuned against. It
+   * is also the semantically right answer: a signature with no body is on the
+   * same side of the line as the interface that owns it, and a call edge
+   * landing on one is still not a file that can answer a flow question.
+   *
+   * The interface ITSELF is untouched: the `references` edges an importing
+   * module aims at `UploadStorage` still disqualify the file under (4), which
+   * is what keeps a depended-on `types.ts` out of the flag.
+   *
    * Bounded-lookup like {@link getGeneratedPathsAmong}: callers hold a ranked
    * candidate list, so this is a partial-index probe over a handful of paths.
    */
@@ -2751,14 +2792,15 @@ export class QueryBuilder {
       // things the file declares, so they neither qualify nor disqualify.
       const rows = this.db
         .prepare(`
-          SELECT file_path,
-                 SUM(CASE WHEN kind NOT IN ('file','import','export','parameter')
+          SELECT n.file_path AS file_path,
+                 SUM(CASE WHEN n.kind NOT IN ('file','import','export','parameter')
+                           AND NOT ${IS_INTERFACE_MEMBER('n')}
                           THEN 1 ELSE 0 END) AS declared,
-                 SUM(CASE WHEN kind IN ('interface','type_alias','enum','enum_member','namespace')
+                 SUM(CASE WHEN n.kind IN ('interface','type_alias','enum','enum_member','namespace')
                           THEN 1 ELSE 0 END) AS typeDeclared
-          FROM nodes
-          WHERE file_path IN (${placeholders})
-          GROUP BY file_path
+          FROM nodes n
+          WHERE n.file_path IN (${placeholders})
+          GROUP BY n.file_path
         `)
         .all(...chunk) as Array<{ file_path: string; declared: number; typeDeclared: number }>;
       let candidates = rows
@@ -2775,17 +2817,22 @@ export class QueryBuilder {
         );
         candidates = candidates.filter((p) => !hit.has(p));
       };
-      // (3) originates behaviour
+      // (3) originates behaviour — a signature has no body to originate from,
+      // so an edge attributed to one is not evidence about this file.
       disqualify(`
         SELECT DISTINCT n.file_path AS file_path
         FROM edges e JOIN nodes n ON n.id = e.source
         WHERE e.kind IN ('calls','instantiates') AND n.file_path IN ($IN$)
+          AND NOT ${IS_INTERFACE_MEMBER('n')}
       `);
-      // (4) something outside the file depends on it
+      // (4) something outside the file depends on it — but a call that lands on
+      // an interface's own signature is a use of the API, not a dependency on
+      // this file's structure. The edges aimed at the interface still count.
       disqualify(`
         SELECT DISTINCT t.file_path AS file_path
         FROM edges e JOIN nodes t ON t.id = e.target JOIN nodes s ON s.id = e.source
         WHERE t.file_path IN ($IN$) AND s.file_path <> t.file_path
+          AND NOT ${IS_INTERFACE_MEMBER('t')}
       `);
       for (const path of candidates) found.add(path);
     }

src/extraction/languages/typescript.ts

@@ -41,8 +41,15 @@ export function classifyTsClassMember(node: SyntaxNode): 'method' | 'property' {
 export const typescriptExtractor: LanguageExtractor = {
   functionTypes: ['function_declaration', 'generator_function_declaration', 'arrow_function', 'function_expression', 'generator_function'],
   classTypes: ['class_declaration', 'abstract_class_declaration'],
-  methodTypes: ['method_definition', 'public_field_definition'],
+  // `method_signature` is the interface/type-literal form of a method; without it
+  // an interface's members never enter the graph, so a `.d.ts` platform API has
+  // no declaration node for call sites to attach to (#1638). Java/C# don't need
+  // an equivalent — their grammars reuse `method_declaration`.
+  methodTypes: ['method_definition', 'public_field_definition', 'method_signature'],
   classifyMethodNode: classifyTsClassMember,
+  // The interface counterpart of `public_field_definition`. It carries no value,
+  // so it is always a property and never needs classifyMethodNode.
+  propertyTypes: ['property_signature'],
   interfaceTypes: ['interface_declaration'],
   structTypes: [],
   enumTypes: ['enum_declaration'],

src/extraction/tree-sitter.ts

@@ -52,6 +52,20 @@ const RTK_HOOK_NAME_RE = /^use[A-Z][A-Za-z0-9]*(?:Query|Mutation)$/;
  *  initialized with one of these is a component, not a constant (#841). */
 const REACT_COMPONENT_HOCS = new Set(['forwardRef', 'memo', 'React.forwardRef', 'React.memo']);
 
+/**
+ * Method node types that spell a SIGNATURE — a declaration with no body (#1638).
+ *
+ * They are a method of whatever type declares them and nothing on their own, so
+ * they must not take `extractMethod`'s "no class-like parent, so treat it as a
+ * free function" fallback. The other `methodTypes` can: a `method_definition`
+ * outside a class really is a function. This one appears outside a class only
+ * inside a type literal (`type Handle = { stop(): void }`), whose members
+ * `extractTypeAlias` already extracts and attaches to the alias (#359) — take
+ * the fallback and the file gains a phantom top-level `function stop` beside
+ * the real `Handle::stop`.
+ */
+const SIGNATURE_METHOD_NODE_TYPES = new Set(['method_signature']);
+
 /** Vue store collections whose object-literal members are the symbols an agent
  *  looks for. Extracted as function nodes so `actions`/`mutations`/`getters` are
  *  findable + readable (the foundation under any later dispatch-bridge synth). */
@@ -1073,8 +1087,13 @@ export class TreeSitterExtractor {
       this.extractClass(node);
       skipChildren = true;
     }
-    // Check for method declarations (only if not already handled by functionTypes)
-    else if (this.extractor.methodTypes.includes(nodeType)) {
+    // Check for method declarations (only if not already handled by functionTypes).
+    // A bodiless SIGNATURE only counts as one where a type declares it — see
+    // SIGNATURE_METHOD_NODE_TYPES for what falling through would otherwise mint.
+    else if (
+      this.extractor.methodTypes.includes(nodeType)
+      && (!SIGNATURE_METHOD_NODE_TYPES.has(nodeType) || this.isInsideClassLikeNode())
+    ) {
       // TS/JS class fields parse as a methodTypes node; only function-valued
       // fields are methods — a plain field (`public fonts: Fonts;`) is a
       // property (#808). C++ lists `field_declaration` so pure-virtual methods
@@ -1335,22 +1354,16 @@ export class TreeSitterExtractor {
     else if (nodeType === 'impl_item') {
       this.extractRustImplItem(node);
     }
-    // TypeScript interface members: property_signature (`foo: T`, `foo?: T`)
-    // and method_signature (`foo(arg: A): R`) both carry type annotations the
-    // interface walker would otherwise drop. Extract them as `references`
-    // edges from the interface so resolvers can wire callers/impact for
-    // types that only appear in interface members.
-    else if (
-      (nodeType === 'property_signature' || nodeType === 'method_signature') &&
-      this.isInsideClassLikeNode() &&
-      this.TYPE_ANNOTATION_LANGUAGES.has(this.language)
-    ) {
-      const parentId = this.nodeStack[this.nodeStack.length - 1];
-      if (parentId) {
-        this.extractTypeAnnotations(node, parentId);
-      }
-      // don't skipChildren — nested signatures still need traversal
-    }
+    // NOTE: `property_signature` / `method_signature` used to be handled here,
+    // hanging their type annotations off the ENCLOSING INTERFACE — the only
+    // anchor available while the members themselves went unextracted. Since
+    // #1638 they are in the TS extractor's `methodTypes` / `propertyTypes`, so
+    // the branches above claim them first (under the same `isInsideClassLikeNode`
+    // guard this branch had, so nothing it used to reach is now missed) and this
+    // one was dead. The `references` edges survive — `extractMethod` and
+    // `extractProperty` each call `extractTypeAnnotations` — but now hang off
+    // the member, which is the more precise anchor: `Api::fetch → PageId` says
+    // which member wants the type, where `Api → PageId` only said the file did.
 
     // Visit children (unless the extract method already visited them)
     if (!skipChildren) {
@@ -2096,8 +2109,18 @@ export class TreeSitterExtractor {
     // and the initializer VALUE, which the generic finder below would
     // wrongly pick — so fields use the type field only (#808). Other
     // languages (C# property_declaration) keep the generic scan.
+    //
+    // A `property_signature` (an interface member, #1638) carries a `type`
+    // field and no value, so it reads the type field too. It cannot take the
+    // generic scan: that scan's exclusion list covers `identifier` but not the
+    // `property_identifier` an interface member is named with, so it stops on
+    // the name and `interface Stats { counts: Record<string, number> }` yields
+    // `signature: "counts counts"` instead of the type. Named explicitly
+    // rather than folded into the field test so no other language's
+    // `property_declaration` moves off the generic scan.
     const isTsJsField =
-      node.type === 'public_field_definition' || node.type === 'field_definition';
+      node.type === 'public_field_definition' || node.type === 'field_definition'
+      || node.type === 'property_signature';
     const typeNode = isTsJsField
       ? getChildByField(node, 'type')
       : node.namedChildren.find(

src/mcp/tools.ts

@@ -358,6 +358,14 @@ export const RELEVANCE_KIND_WEIGHT: Readonly<Record<string, number>> = {
 };
 const DEFAULT_RELEVANCE_KIND_WEIGHT = 0.5;
 
+/**
+ * The "member of a type" tier of the table above, named so the one kind that
+ * cannot be read off `node.kind` can be placed on it: an interface's
+ * `method_signature` (#1638). Same value as `property`/`field`, deliberately —
+ * it is the same tier, not a new one.
+ */
+const TYPE_MEMBER_RELEVANCE_WEIGHT = 0.5;
+
 /**
  * Kinds whose evidentiary value depends on whether anything USES them. An
  * exported `const DEFAULTS` that half the codebase references is a real
@@ -3465,6 +3473,35 @@ export class ToolHandler {
     // substantive definition (skip empty stubs + test files, same relevance the
     // trace endpoint picker uses) and inject it as an entry, so every symbol the
     // agent explicitly named is in the subgraph and its file is scored.
+    /**
+     * Is this a member an INTERFACE declares — a signature with no body (#1638)?
+     *
+     * It arrives as an ordinary `method` node, so without asking, every ranking
+     * stage reads a `.d.ts` full of `method_signature`s as a file full of
+     * callables. Two stages below ask, for the same reason: a signature is the
+     * declaration of behaviour, never behaviour, and the rank a file earns must
+     * not grow just because its interfaces spell their members out.
+     *
+     * Cached; reached only for `method` nodes on paths that already probe the
+     * graph per node, so it adds a key lookup, not a pass.
+     */
+    const interfaceMemberCache = new Map<string, boolean>();
+    const isInterfaceOwnedMethod = (node: Node): boolean => {
+      if (node.kind !== 'method') return false;
+      const cached = interfaceMemberCache.get(node.id);
+      if (cached !== undefined) return cached;
+      let owned = false;
+      try {
+        owned = cg.getIncomingEdges(node.id).some(
+          (e) => e.kind === 'contains' && cg.getNode(e.source)?.kind === 'interface',
+        );
+      } catch {
+        owned = false; // a probe failure must not manufacture a penalty
+      }
+      interfaceMemberCache.set(node.id, owned);
+      return owned;
+    };
+
     const namedSeedIds = new Set<string>();
     // The subset of named seeds that earns the named-FIRST sort tier. We still
     // SEED every ≤3-def name (so RWR / flow ranking is unchanged), but only the
@@ -3635,7 +3672,21 @@ export class ToolHandler {
           // so a named symbol FTS already gathered never sorted to the top.)
           namedSeedIds.add(n.id);
         }
-        for (const n of tierPicks) tierSeedIds.add(n.id);
+        // An interface's `method_signature` seeds (so RWR and the flow ranking
+        // still see it, and a query that names it still reaches its file) but
+        // never earns the named-FIRST tier (#1638). That tier means "the agent
+        // asked for the symbol DEFINED here", and this seeding says as much —
+        // it resolves a token to its substantive definition and sorts bodies
+        // first. A declaration is the stub that sort demotes, not the answer.
+        // Without this the tier is reachable by prose: `body`, `stream` and
+        // `metadata` are member names in any platform `.d.ts`, and each one
+        // corroborates the next through `coNamedInFile`, so an ambient shim
+        // walks past the NL-stopword guard and lands above every implementation
+        // file — the exact inversion CG-28 exists to prevent, arriving on a key
+        // that sorts above the CG-28 penalty.
+        for (const n of tierPicks) {
+          if (!isInterfaceOwnedMethod(n)) tierSeedIds.add(n.id);
+        }
       }
     }
 
@@ -3686,9 +3737,21 @@ export class ToolHandler {
       isolationCache.set(node.id, isolated);
       return isolated;
     };
+    /**
+     * A `method_signature` reaches here as a `method`, which the kind table
+     * rates 1.0: "a callable — the unit an architecture question is about". It
+     * is not that. It is the row below on the same scale, "a member of a type",
+     * and rating it as a callable is how a 28-interface `.d.ts` doubled its
+     * score the moment its members became indexable (#1638). Only `method`
+     * needs correcting; `property` already sits in the member tier whoever
+     * declares it.
+     */
     const relevanceWeight = (node: Node, probeIsolation: boolean): number => {
-      const weight = RELEVANCE_KIND_WEIGHT[node.kind] ?? DEFAULT_RELEVANCE_KIND_WEIGHT;
-      if (!probeIsolation || !WEAK_RELEVANCE_KINDS.has(node.kind)) return weight;
+      const signatureOnly = isInterfaceOwnedMethod(node);
+      const weight = signatureOnly
+        ? TYPE_MEMBER_RELEVANCE_WEIGHT
+        : RELEVANCE_KIND_WEIGHT[node.kind] ?? DEFAULT_RELEVANCE_KIND_WEIGHT;
+      if (!probeIsolation || !(signatureOnly || WEAK_RELEVANCE_KINDS.has(node.kind))) return weight;
       return isUsageIsolated(node) ? ISOLATED_WEAK_KIND_WEIGHT : weight;
     };
 
@@ -3916,8 +3979,33 @@ export class ToolHandler {
     // (org-user.storage.ts, call-connected to the matches) accrues mass; a lone
     // text match (LensSwitcher.swift, matched "switch" but calls nothing in the
     // flow) gets only its restart probability → ~0, and is dropped by the gate.
+    //
+    // A file the ambient-declaration penalty has already damped is a candidate,
+    // but not a place a walk STARTS. The restart vector is uniform over seeds,
+    // so every seed divides the restart mass the implementation files compete
+    // for — and since #1638 a platform `.d.ts` contributes one seed per member,
+    // whose names (`body`, `stream`, `metadata`) are exactly what a prose flow
+    // query matches. That is what halves an implementation file's graph mass
+    // while the shim's holds steady: dilution of the restart vector, not
+    // connectivity. `contains` is not a RANK_EDGE, so these members carry almost
+    // no walk mass of their own; seeding is the whole of their effect on rank.
+    //
+    // `isDampedDeclaration` and not a bare ambient test: it already exempts a
+    // file whose declared type the query NAMED, so a query genuinely about the
+    // declared type keeps its seeds and the shim still ranks first. Damped files
+    // stay in the candidate set, stay reachable, and keep their `score`
+    // contribution — this changes only where the walk starts.
+    const rwrSeedIds = new Set<string>();
+    for (const id of entryNodeIds) {
+      const seed = subgraph.nodes.get(id);
+      if (seed && isDampedDeclaration(seed.filePath)) continue;
+      rwrSeedIds.add(id);
+    }
     const nodeRwr = this.computeGraphRelevance(
-      [...subgraph.nodes.keys()], subgraph.edges, entryNodeIds,
+      // Fall back to the unfiltered seeds when EVERY seed is damped: the walk
+      // must not lose its restart vector and return all-uniform.
+      [...subgraph.nodes.keys()], subgraph.edges,
+      rwrSeedIds.size > 0 ? rwrSeedIds : entryNodeIds,
     );
     //
     // Carries `rankPenalty` too, so generated/low-value files are demoted on the