diff --git a/eslint-rules/require-safe-parse.mjs b/eslint-rules/require-safe-parse.mjs
new file mode 100644
index 000000000..4ab9dbd8a
--- /dev/null
+++ b/eslint-rules/require-safe-parse.mjs
@@ -0,0 +1,95 @@
+/**
+ * Custom ESLint rule: require `parseSourceSafe(parser, content, ...)` instead
+ * of direct `<parser>.parse(<content>, ...)` calls.
+ *
+ * Background: tree-sitter's Node.js native binding crashes with SIGSEGV on
+ * Windows when handed a JS string longer than 32 767 chars. The crash happens
+ * inside the binding's V8 string-to-buffer conversion and cannot be intercepted
+ * by JavaScript `try/catch`. `parseSourceSafe` (in
+ * `gitnexus/src/core/tree-sitter/safe-parse.ts`) routes large inputs through
+ * the chunked-callback overload of `parser.parse(input, ...)` which bypasses
+ * the broken conversion path. PR #1433 fixed every direct call site at the
+ * time; this rule prevents new direct calls from creeping in.
+ *
+ * The rule is auto-fixable for the call-site rewrite. It does NOT auto-add the
+ * import (computing the correct relative path per file is brittle); after the
+ * call rewrite runs, the consumer file's `tsc` will complain about an
+ * undefined identifier and the developer adds the import. This is the same
+ * tradeoff `unused-imports/no-unused-imports` makes in the opposite direction.
+ *
+ * False-positive suppression:
+ * - Skips calls whose receiver is a known non-tree-sitter library (`JSON`,
+ *   `URL`, `marked`, `Number`).
+ * - Skips calls whose first argument is a string-literal (grammar-load smoke
+ *   tests like `_testParser.parse('service X { rpc Y (R) returns (R); }')`).
+ * - Skips test files (`.test.ts`/`.test.tsx`/`.spec.ts`).
+ * - Skips the `safe-parse.ts` helper itself.
+ */
+
+const SKIPPED_RECEIVERS = new Set(['JSON', 'URL', 'marked', 'Number', 'Math']);
+
+export default {
+  meta: {
+    type: 'problem',
+    docs: {
+      description:
+        'Require parseSourceSafe instead of direct tree-sitter `<parser>.parse(content, ...)` calls (Windows SIGSEGV protection)',
+      recommended: true,
+    },
+    fixable: 'code',
+    schema: [],
+    messages: {
+      useSafeParse:
+        'Direct `{{receiver}}.parse(...)` can SIGSEGV on Windows for inputs > 32 767 chars (uncatchable from JS). Use `parseSourceSafe({{receiver}}, ...)` from `core/tree-sitter/safe-parse.js`. Auto-fix rewrites the call; add the missing import yourself.',
+    },
+  },
+  create(context) {
+    const filename = context.filename ?? context.getFilename();
+    // Don't lint the helper itself or test files.
+    if (filename.includes('safe-parse')) return {};
+    if (/[.](?:test|spec)\.tsx?$/.test(filename)) return {};
+
+    const sourceCode = context.sourceCode ?? context.getSourceCode();
+
+    return {
+      CallExpression(node) {
+        const callee = node.callee;
+        if (callee.type !== 'MemberExpression') return;
+        if (callee.computed) return;
+        if (callee.property.type !== 'Identifier') return;
+        if (callee.property.name !== 'parse') return;
+
+        // Skip known non-tree-sitter receivers.
+        if (callee.object.type === 'Identifier' && SKIPPED_RECEIVERS.has(callee.object.name)) {
+          return;
+        }
+
+        // Smoke tests pass a string literal directly; those are trivially safe.
+        const firstArg = node.arguments[0];
+        if (!firstArg) return;
+        if (firstArg.type === 'Literal' && typeof firstArg.value === 'string') return;
+        if (firstArg.type === 'TemplateLiteral' && firstArg.expressions.length === 0) return;
+
+        const receiverText = sourceCode.getText(callee.object);
+        // Receiver-text-shape skip: anything matching well-known JS APIs that
+        // happen to have a `.parse(<expr>)` shape but aren't tree-sitter.
+        if (
+          /^(JSON|URL|marked|Number|Math|Date|globalThis\.JSON)\b/.test(receiverText) ||
+          /\bjson\.parse\b/i.test(receiverText)
+        ) {
+          return;
+        }
+
+        context.report({
+          node,
+          messageId: 'useSafeParse',
+          data: { receiver: receiverText },
+          fix(fixer) {
+            const argsText = node.arguments.map((arg) => sourceCode.getText(arg)).join(', ');
+            return fixer.replaceText(node, `parseSourceSafe(${receiverText}, ${argsText})`);
+          },
+        });
+      },
+    };
+  },
+};
diff --git a/eslint.config.mjs b/eslint.config.mjs
index f377cba6c..e0779b71c 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -3,6 +3,15 @@ import tsParser from '@typescript-eslint/parser';
 import unusedImports from 'eslint-plugin-unused-imports';
 import reactHooks from 'eslint-plugin-react-hooks';
 import prettierConfig from 'eslint-config-prettier';
+import requireSafeParse from './eslint-rules/require-safe-parse.mjs';
+
+// Local plugin hosting custom rules that enforce GitNexus-specific invariants
+// (currently: the Windows-SIGSEGV-safe parser entrypoint).
+const gitnexusLocalPlugin = {
+  rules: {
+    'require-safe-parse': requireSafeParse,
+  },
+};
 
 // Selectors that protect MCP-reachable code from corrupting the JSON-RPC
 // stdio frame stream. The MCP-reachable block below uses these directly;
@@ -135,6 +144,23 @@ export default [
     },
   },
 
+  // Windows SIGSEGV protection: every tree-sitter parse in `core/` must route
+  // through parseSourceSafe. Direct `<parser>.parse(content, ...)` crashes on
+  // Windows for inputs > 32 767 chars (V8 string-conversion bug, uncatchable
+  // from JS). The rule auto-fixes the call site; the developer adds the
+  // missing import after the fix runs. Out of scope: tests (skipped by the
+  // rule), the helper itself (`safe-parse.ts`), and the `grpc-patterns/proto.ts`
+  // grammar-load smoke test (filtered by string-literal-arg skip in the rule).
+  {
+    files: ['gitnexus/src/core/**/*.ts'],
+    plugins: {
+      gitnexus: gitnexusLocalPlugin,
+    },
+    rules: {
+      'gitnexus/require-safe-parse': 'error',
+    },
+  },
+
   // React-specific rules for gitnexus-web
   {
     files: ['gitnexus-web/src/**/*.{ts,tsx}'],
diff --git a/gitnexus/src/core/embeddings/ast-utils.ts b/gitnexus/src/core/embeddings/ast-utils.ts
index 8456b249e..e4976d71e 100644
--- a/gitnexus/src/core/embeddings/ast-utils.ts
+++ b/gitnexus/src/core/embeddings/ast-utils.ts
@@ -10,6 +10,7 @@ import {
   isLanguageAvailable,
   resolveLanguageKey,
 } from '../tree-sitter/parser-loader.js';
+import { parseSourceSafe } from '../tree-sitter/safe-parse.js';
 
 const parserCache = new Map<string, any>();
 
@@ -29,7 +30,7 @@ export const ensureAndParse = async (content: string, filePath: string): Promise
     parserCache.set(parserKey, parserInstance);
   }
 
-  return parserInstance.parse(content);
+  return parseSourceSafe(parserInstance, content);
 };
 
 const FUNCTION_LIKE_TYPES = new Set([
diff --git a/gitnexus/src/core/group/extractors/grpc-extractor.ts b/gitnexus/src/core/group/extractors/grpc-extractor.ts
index c08ba7c36..56107d8ee 100644
--- a/gitnexus/src/core/group/extractors/grpc-extractor.ts
+++ b/gitnexus/src/core/group/extractors/grpc-extractor.ts
@@ -5,6 +5,7 @@ import { createIgnoreFilter } from '../../../config/ignore-service.js';
 import type { ContractExtractor, CypherExecutor } from '../contract-extractor.js';
 import type { ExtractedContract, RepoHandle } from '../types.js';
 import { readSafe } from './fs-utils.js';
+import { parseSourceSafe } from '../../tree-sitter/safe-parse.js';
 import { logger } from '../../logger.js';
 import {
   GRPC_SCAN_GLOB,
@@ -428,7 +429,7 @@ export class GrpcExtractor implements ContractExtractor {
       let detections: GrpcDetection[] = [];
       try {
         parser.setLanguage(plugin.language);
-        const tree = parser.parse(content);
+        const tree = parseSourceSafe(parser, content);
         detections = plugin.scan(tree);
       } catch {
         continue;
diff --git a/gitnexus/src/core/group/extractors/http-route-extractor.ts b/gitnexus/src/core/group/extractors/http-route-extractor.ts
index d989876a8..898a22c38 100644
--- a/gitnexus/src/core/group/extractors/http-route-extractor.ts
+++ b/gitnexus/src/core/group/extractors/http-route-extractor.ts
@@ -5,6 +5,7 @@ import { createIgnoreFilter } from '../../../config/ignore-service.js';
 import type { ContractExtractor, CypherExecutor } from '../contract-extractor.js';
 import type { ExtractedContract, RepoHandle } from '../types.js';
 import { readSafe } from './fs-utils.js';
+import { parseSourceSafe } from '../../tree-sitter/safe-parse.js';
 import { getPluginForFile, HTTP_SCAN_GLOB, type HttpDetection } from './http-patterns/index.js';
 
 /**
@@ -172,7 +173,7 @@ export class HttpRouteExtractor implements ContractExtractor {
       }
       try {
         parser.setLanguage(plugin.language);
-        const tree = parser.parse(content);
+        const tree = parseSourceSafe(parser, content);
         const detections = plugin.scan(tree);
         cachedDetections.set(rel, detections);
         return detections;
diff --git a/gitnexus/src/core/group/extractors/include-extractor.ts b/gitnexus/src/core/group/extractors/include-extractor.ts
index 7bbfd61ed..98cbd371f 100644
--- a/gitnexus/src/core/group/extractors/include-extractor.ts
+++ b/gitnexus/src/core/group/extractors/include-extractor.ts
@@ -10,6 +10,7 @@ import { readSafe } from './fs-utils.js';
 import { buildSuffixIndex, type SuffixIndex } from '../../ingestion/import-resolvers/utils.js';
 import { createIgnoreFilter } from '../../../config/ignore-service.js';
 import { getMaxFileSizeBytes } from '../../ingestion/utils/max-file-size.js';
+import { parseSourceSafe } from '../../tree-sitter/safe-parse.js';
 import { logger } from '../../logger.js';
 
 /**
@@ -505,7 +506,7 @@ export class IncludeExtractor implements ContractExtractor {
       let extractionSource: 'tree_sitter' | 'regex_fallback';
       try {
         parser.setLanguage(lang);
-        const tree = parser.parse(content);
+        const tree = parseSourceSafe(parser, content);
         let matches: Parser.QueryMatch[];
         try {
           matches = query.matches(tree.rootNode);
diff --git a/gitnexus/src/core/group/extractors/thrift-extractor.ts b/gitnexus/src/core/group/extractors/thrift-extractor.ts
index 709968790..7d23e19cc 100644
--- a/gitnexus/src/core/group/extractors/thrift-extractor.ts
+++ b/gitnexus/src/core/group/extractors/thrift-extractor.ts
@@ -3,6 +3,7 @@ import Parser from 'tree-sitter';
 import type { ContractExtractor, CypherExecutor } from '../contract-extractor.js';
 import type { ExtractedContract, RepoHandle } from '../types.js';
 import { readSafe } from './fs-utils.js';
+import { parseSourceSafe } from '../../tree-sitter/safe-parse.js';
 import {
   getPluginForFile,
   THRIFT_SCAN_GLOB,
@@ -311,7 +312,7 @@ export class ThriftExtractor implements ContractExtractor {
       let detections: ThriftDetection[] = [];
       try {
         parser.setLanguage(plugin.language);
-        const tree = parser.parse(content);
+        const tree = parseSourceSafe(parser, content);
         detections = plugin.scan(tree);
       } catch {
         continue;
diff --git a/gitnexus/src/core/group/extractors/tree-sitter-scanner.ts b/gitnexus/src/core/group/extractors/tree-sitter-scanner.ts
index cd50456aa..0463e8f0c 100644
--- a/gitnexus/src/core/group/extractors/tree-sitter-scanner.ts
+++ b/gitnexus/src/core/group/extractors/tree-sitter-scanner.ts
@@ -1,4 +1,5 @@
 import Parser from 'tree-sitter';
+import { parseSourceSafe } from '../../tree-sitter/safe-parse.js';
 
 /**
  * Shared, language-agnostic tree-sitter scanning utilities used by group
@@ -155,7 +156,7 @@ export function scanFile<TMeta>(
   let tree: Parser.Tree;
   try {
     parser.setLanguage(plugin.language);
-    tree = parser.parse(content);
+    tree = parseSourceSafe(parser, content);
   } catch {
     return [];
   }
diff --git a/gitnexus/src/core/ingestion/call-processor.ts b/gitnexus/src/core/ingestion/call-processor.ts
index bf0206057..9fa6c1ae5 100644
--- a/gitnexus/src/core/ingestion/call-processor.ts
+++ b/gitnexus/src/core/ingestion/call-processor.ts
@@ -40,6 +40,7 @@ import { getLanguageFromFilename, SupportedLanguages } from 'gitnexus-shared';
 import { isRegistryPrimary } from './registry-primary-flag.js';
 import { isVerboseIngestionEnabled } from './utils/verbose.js';
 import { yieldToEventLoop } from './utils/event-loop.js';
+import { parseSourceSafe } from '../tree-sitter/safe-parse.js';
 import {
   FUNCTION_NODE_TYPES,
   findEnclosingClassId,
@@ -771,7 +772,7 @@ export const processCalls = async (
     if (!tree) {
       const parseContent = provider.preprocessSource?.(file.content, file.path) ?? file.content;
       try {
-        tree = parser.parse(parseContent, undefined, {
+        tree = parseSourceSafe(parser, parseContent, undefined, {
           bufferSize: getTreeSitterBufferSize(parseContent),
         });
       } catch (parseError) {
@@ -3283,7 +3284,7 @@ export const extractFetchCallsFromFiles = async (
     if (!tree) {
       const parseContent = provider.preprocessSource?.(file.content, file.path) ?? file.content;
       try {
-        tree = parser.parse(parseContent, undefined, {
+        tree = parseSourceSafe(parser, parseContent, undefined, {
           bufferSize: getTreeSitterBufferSize(parseContent),
         });
       } catch {
diff --git a/gitnexus/src/core/ingestion/heritage-processor.ts b/gitnexus/src/core/ingestion/heritage-processor.ts
index f8628e651..c223bd286 100644
--- a/gitnexus/src/core/ingestion/heritage-processor.ts
+++ b/gitnexus/src/core/ingestion/heritage-processor.ts
@@ -22,6 +22,7 @@ import { generateId } from '../../lib/utils.js';
 import { getLanguageFromFilename, type NodeLabel, type SupportedLanguages } from 'gitnexus-shared';
 import { isVerboseIngestionEnabled } from './utils/verbose.js';
 import { yieldToEventLoop } from './utils/event-loop.js';
+import { parseSourceSafe } from '../tree-sitter/safe-parse.js';
 import { getProvider } from './languages/index.js';
 import { getTreeSitterBufferSize } from './constants.js';
 import type {
@@ -224,7 +225,7 @@ export const processHeritage = async (
       // re-parses see the same input as the cached AST.
       const parseContent = provider.preprocessSource?.(file.content, file.path) ?? file.content;
       try {
-        tree = parser.parse(parseContent, undefined, {
+        tree = parseSourceSafe(parser, parseContent, undefined, {
           bufferSize: getTreeSitterBufferSize(parseContent),
         });
       } catch (parseError) {
@@ -419,7 +420,7 @@ export async function extractExtractedHeritageFromFiles(
     if (!tree) {
       const parseContent = provider.preprocessSource?.(file.content, file.path) ?? file.content;
       try {
-        tree = parser.parse(parseContent, undefined, {
+        tree = parseSourceSafe(parser, parseContent, undefined, {
           bufferSize: getTreeSitterBufferSize(parseContent),
         });
       } catch {
diff --git a/gitnexus/src/core/ingestion/import-processor.ts b/gitnexus/src/core/ingestion/import-processor.ts
index 6f0b40b6f..f7742faa1 100644
--- a/gitnexus/src/core/ingestion/import-processor.ts
+++ b/gitnexus/src/core/ingestion/import-processor.ts
@@ -8,6 +8,7 @@ import { generateId } from '../../lib/utils.js';
 import { getLanguageFromFilename } from 'gitnexus-shared';
 import { isVerboseIngestionEnabled } from './utils/verbose.js';
 import { yieldToEventLoop } from './utils/event-loop.js';
+import { parseSourceSafe } from '../tree-sitter/safe-parse.js';
 import type { ExtractedImport } from './workers/parse-worker.js';
 import { getTreeSitterBufferSize } from './constants.js';
 import { loadImportConfigs } from './language-config.js';
@@ -307,7 +308,7 @@ export const processImports = async (
     if (!tree) {
       const parseContent = provider.preprocessSource?.(file.content, file.path) ?? file.content;
       try {
-        tree = parser.parse(parseContent, undefined, {
+        tree = parseSourceSafe(parser, parseContent, undefined, {
           bufferSize: getTreeSitterBufferSize(parseContent),
         });
       } catch (parseError) {
diff --git a/gitnexus/src/core/ingestion/languages/csharp/captures.ts b/gitnexus/src/core/ingestion/languages/csharp/captures.ts
index e29552e78..a090b82f8 100644
--- a/gitnexus/src/core/ingestion/languages/csharp/captures.ts
+++ b/gitnexus/src/core/ingestion/languages/csharp/captures.ts
@@ -24,6 +24,7 @@ import { synthesizeCsharpReceiverBinding } from './receiver-binding.js';
 import { getCsharpParser, getCsharpScopeQuery } from './query.js';
 import { recordCacheHit, recordCacheMiss } from './cache-stats.js';
 import { getTreeSitterBufferSize } from '../../constants.js';
+import { parseSourceSafe } from '../../../tree-sitter/safe-parse.js';
 
 /** Declaration anchors that carry function-like arity metadata. */
 const FUNCTION_DECL_TAGS = [
@@ -86,7 +87,7 @@ export function emitCsharpScopeCaptures(
   // the LanguageProvider contract layer; cast here at the use site.
   let tree = cachedTree as ReturnType<ReturnType<typeof getCsharpParser>['parse']> | undefined;
   if (tree === undefined) {
-    tree = getCsharpParser().parse(sourceText, undefined, {
+    tree = parseSourceSafe(getCsharpParser(), sourceText, undefined, {
       bufferSize: getTreeSitterBufferSize(sourceText),
     });
     recordCacheMiss();
diff --git a/gitnexus/src/core/ingestion/languages/csharp/namespace-siblings.ts b/gitnexus/src/core/ingestion/languages/csharp/namespace-siblings.ts
index 2cd2cf724..b6de589e2 100644
--- a/gitnexus/src/core/ingestion/languages/csharp/namespace-siblings.ts
+++ b/gitnexus/src/core/ingestion/languages/csharp/namespace-siblings.ts
@@ -36,6 +36,7 @@ import type { BindingRef, ParsedFile, Scope, ScopeId, SymbolDefinition } from 'g
 import type { ScopeResolutionIndexes } from '../../model/scope-resolution-indexes.js';
 import { getCsharpParser } from './query.js';
 import { getTreeSitterBufferSize } from '../../constants.js';
+import { parseSourceSafe } from '../../../tree-sitter/safe-parse.js';
 
 interface CsharpFileStructure {
   /** Declared namespace names in file source order. Empty array means
@@ -56,7 +57,7 @@ function extractFileStructure(content: string, cachedTree: unknown): CsharpFileS
   type CsharpTree = ReturnType<ReturnType<typeof getCsharpParser>['parse']>;
   const tree =
     (cachedTree as CsharpTree | undefined) ??
-    getCsharpParser().parse(content, undefined, {
+    parseSourceSafe(getCsharpParser(), content, undefined, {
       bufferSize: getTreeSitterBufferSize(content),
     });
   const namespaces: string[] = [];
@@ -359,7 +360,7 @@ export function populateCsharpNamespaceSiblings(
       const q = def.qualifiedName ?? '';
       const key = q.includes('.') ? q.slice(q.lastIndexOf('.') + 1) : q;
       if (key === '') continue;
-      const arr = defsByName.get(key) ?? [];
+      const arr = [...(defsByName.get(key) ?? [])];
       arr.push(def);
       defsByName.set(key, arr);
     }
diff --git a/gitnexus/src/core/ingestion/languages/go/captures.ts b/gitnexus/src/core/ingestion/languages/go/captures.ts
index 93fcbc51a..73fa61862 100644
--- a/gitnexus/src/core/ingestion/languages/go/captures.ts
+++ b/gitnexus/src/core/ingestion/languages/go/captures.ts
@@ -12,6 +12,7 @@ import { splitGoImportStatement } from './import-decomposer.js';
 import { synthesizeGoReceiverBinding } from './receiver-binding.js';
 import { synthesizeGoTypeBindings } from './type-binding.js';
 import { getTreeSitterBufferSize } from '../../constants.js';
+import { parseSourceSafe } from '../../../tree-sitter/safe-parse.js';
 
 export function emitGoScopeCaptures(
   sourceText: string,
@@ -20,7 +21,7 @@ export function emitGoScopeCaptures(
 ): readonly CaptureMatch[] {
   let tree = cachedTree as ReturnType<ReturnType<typeof getGoParser>['parse']> | undefined;
   if (tree === undefined) {
-    tree = getGoParser().parse(sourceText, undefined, {
+    tree = parseSourceSafe(getGoParser(), sourceText, undefined, {
       bufferSize: getTreeSitterBufferSize(sourceText),
     });
     recordGoCacheMiss();
diff --git a/gitnexus/src/core/ingestion/languages/go/range-binding.ts b/gitnexus/src/core/ingestion/languages/go/range-binding.ts
index 14e520c2d..1f06f3373 100644
--- a/gitnexus/src/core/ingestion/languages/go/range-binding.ts
+++ b/gitnexus/src/core/ingestion/languages/go/range-binding.ts
@@ -2,6 +2,7 @@ import type { ParsedFile, Scope, TypeRef } from 'gitnexus-shared';
 import type { ScopeResolutionIndexes } from '../../model/scope-resolution-indexes.js';
 import { getGoParser } from './query.js';
 import { getTreeSitterBufferSize } from '../../constants.js';
+import { parseSourceSafe } from '../../../tree-sitter/safe-parse.js';
 
 export function populateGoRangeBindings(
   parsedFiles: readonly ParsedFile[],
@@ -20,7 +21,7 @@ export function populateGoRangeBindings(
     const cachedTree = ctx.treeCache?.get(parsed.filePath);
     const tree =
       (cachedTree as ReturnType<typeof parser.parse> | undefined) ??
-      parser.parse(sourceText, undefined, {
+      parseSourceSafe(parser, sourceText, undefined, {
         bufferSize: getTreeSitterBufferSize(sourceText),
       });
     const moduleScope = parsed.scopes.find((s) => s.kind === 'Module');
diff --git a/gitnexus/src/core/ingestion/languages/python/captures.ts b/gitnexus/src/core/ingestion/languages/python/captures.ts
index be891b5cc..bc4911546 100644
--- a/gitnexus/src/core/ingestion/languages/python/captures.ts
+++ b/gitnexus/src/core/ingestion/languages/python/captures.ts
@@ -24,6 +24,7 @@ import { synthesizeReceiverTypeBinding } from './receiver-binding.js';
 import { computePythonArityMetadata } from './arity-metadata.js';
 import { recordCacheHit, recordCacheMiss } from './cache-stats.js';
 import { getTreeSitterBufferSize } from '../../constants.js';
+import { parseSourceSafe } from '../../../tree-sitter/safe-parse.js';
 import { pythonFunctionDefinitionLabel } from './simple-hooks.js';
 
 export function emitPythonScopeCaptures(
@@ -39,7 +40,7 @@ export function emitPythonScopeCaptures(
   let tree = cachedTree as ReturnType<ReturnType<typeof getPythonParser>['parse']> | undefined;
   if (tree === undefined) {
     try {
-      tree = getPythonParser().parse(sourceText, undefined, {
+      tree = parseSourceSafe(getPythonParser(), sourceText, undefined, {
         bufferSize: getTreeSitterBufferSize(sourceText),
       });
     } catch (err) {
diff --git a/gitnexus/src/core/ingestion/languages/typescript/captures.ts b/gitnexus/src/core/ingestion/languages/typescript/captures.ts
index 9d083c15c..b82edcff8 100644
--- a/gitnexus/src/core/ingestion/languages/typescript/captures.ts
+++ b/gitnexus/src/core/ingestion/languages/typescript/captures.ts
@@ -38,6 +38,7 @@ import { recordCacheHit, recordCacheMiss } from './cache-stats.js';
 import { synthesizeTsReceiverBinding } from './receiver-binding.js';
 import { computeTsArityMetadata } from './arity-metadata.js';
 import { getTreeSitterBufferSize } from '../../constants.js';
+import { parseSourceSafe } from '../../../tree-sitter/safe-parse.js';
 
 /** tree-sitter-typescript node types for function-like scopes that may
  *  carry a synthesized `this` binding. Kept in sync with the
@@ -134,7 +135,7 @@ export function emitTsScopeCaptures(
     tree = undefined;
   }
   if (tree === undefined) {
-    tree = getTsParser(filePath).parse(sourceText, undefined, {
+    tree = parseSourceSafe(getTsParser(filePath), sourceText, undefined, {
       bufferSize: getTreeSitterBufferSize(sourceText),
     });
     recordCacheMiss();
diff --git a/gitnexus/src/core/ingestion/parsing-processor.ts b/gitnexus/src/core/ingestion/parsing-processor.ts
index 98036fbe8..7559b26bc 100644
--- a/gitnexus/src/core/ingestion/parsing-processor.ts
+++ b/gitnexus/src/core/ingestion/parsing-processor.ts
@@ -5,12 +5,11 @@ import { loadParser, loadLanguage, isLanguageAvailable } from '../tree-sitter/pa
 import { getProvider } from './languages/index.js';
 import { generateId } from '../../lib/utils.js';
 import type { SymbolTableReader, SymbolTableWriter, ExtractedHeritage } from './model/index.js';
-// SymbolTableReader is used for the FieldExtractorContext stub; the
-// parsing functions themselves need Writer because they call .add().
 import { ASTCache } from './ast-cache.js';
 import { getLanguageFromFilename, SupportedLanguages } from 'gitnexus-shared';
 import { extractVueScript, isVueSetupTopLevel } from './vue-sfc-extractor.js';
 import { yieldToEventLoop } from './utils/event-loop.js';
+import { parseSourceSafe } from '../tree-sitter/safe-parse.js';
 import { isVerboseIngestionEnabled } from './utils/verbose.js';
 import {
   getDefinitionNodeFromCaptures,
@@ -384,7 +383,7 @@ const processParsingSequential = async (
 
     let tree: Parser.Tree;
     try {
-      tree = parser.parse(parseContent, undefined, {
+      tree = parseSourceSafe(parser, parseContent, undefined, {
         bufferSize: getTreeSitterBufferSize(parseContent),
       });
     } catch (parseError) {
diff --git a/gitnexus/src/core/ingestion/workers/parse-worker.ts b/gitnexus/src/core/ingestion/workers/parse-worker.ts
index 4442b5a65..def4e1299 100644
--- a/gitnexus/src/core/ingestion/workers/parse-worker.ts
+++ b/gitnexus/src/core/ingestion/workers/parse-worker.ts
@@ -20,6 +20,7 @@ import {
   getTreeSitterContentByteLength,
   TREE_SITTER_MAX_BUFFER,
 } from '../constants.js';
+import { parseSourceSafe } from '../../tree-sitter/safe-parse.js';
 import type { SymbolTableReader } from '../model/symbol-table.js';
 import type { ExtractedHeritage } from '../model/heritage-map.js';
 
@@ -1416,7 +1417,7 @@ const processFileGroup = (
 
     let tree;
     try {
-      tree = parser.parse(parseContent, undefined, {
+      tree = parseSourceSafe(parser, parseContent, undefined, {
         bufferSize: getTreeSitterBufferSize(parseContent),
       });
     } catch (err) {
diff --git a/gitnexus/src/core/lbug/lbug-adapter.ts b/gitnexus/src/core/lbug/lbug-adapter.ts
index cb88986ca..fe831cd43 100644
--- a/gitnexus/src/core/lbug/lbug-adapter.ts
+++ b/gitnexus/src/core/lbug/lbug-adapter.ts
@@ -1248,6 +1248,13 @@ export const loadVectorExtension = async (
 ): Promise<boolean> => {
   const useModuleState = targetConn === undefined;
   if (useModuleState && vectorExtensionLoaded) return true;
+  // INSTALL VECTOR crashes with SIGSEGV on Windows: the KuzuDB native extension
+  // installer has an unhandled error path on Windows that raises a fatal signal
+  // that JS try/catch cannot intercept. Skip loading — vector/embedding search
+  // is unavailable but all graph index queries still work. Do NOT set
+  // vectorExtensionLoaded here: the flag means "successfully loaded", and a
+  // subsequent call would otherwise short-circuit to `return true` at the top.
+  if (process.platform === 'win32') return false;
   if (!isVectorExtensionSupportedByPlatform()) return false;
 
   const c: lbug.Connection | null = targetConn ?? conn;
diff --git a/gitnexus/src/core/lbug/pool-adapter.ts b/gitnexus/src/core/lbug/pool-adapter.ts
index ed999907e..f18d7fcc3 100644
--- a/gitnexus/src/core/lbug/pool-adapter.ts
+++ b/gitnexus/src/core/lbug/pool-adapter.ts
@@ -420,7 +420,17 @@ async function doInitLbug(repoId: string, dbPath: string): Promise<void> {
   // install; analyze owns extension installation. If LOAD fails, search
   // features degrade gracefully and the user-facing query path proceeds.
   if (!shared.ftsLoaded) {
-    shared.ftsLoaded = await loadFTSExtension(available[0], { policy: 'load-only' });
+    // Windows guard: LOAD EXTENSION fts crashes with SIGSEGV on Windows when
+    // the FTS extension binary is not installed locally (@ladybugdb/core native
+    // bug — the extension loader hits an unhandled error path that signals SIGSEGV
+    // rather than throwing a JS exception, so try/catch cannot protect here).
+    // Skip the load on Windows; bm25-index.js catches the resulting Kuzu catalog
+    // errors and returns empty BM25 results gracefully. Graph queries are unaffected.
+    if (process.platform === 'win32') {
+      shared.ftsLoaded = true;
+    } else {
+      shared.ftsLoaded = await loadFTSExtension(available[0], { policy: 'load-only' });
+    }
   }
 
   // Register pool entry only after all connections are pre-warmed and FTS is
@@ -484,8 +494,13 @@ export async function initLbugWithDb(
   // Load FTS extension if not already loaded on this Database.
   // policy: 'load-only' — same contract as initLbug above; the read pool
   // must not block on a network install during query execution.
+  // Windows guard: same SIGSEGV risk as doInitLbug above — skip on Windows.
   if (!shared.ftsLoaded) {
-    shared.ftsLoaded = await loadFTSExtension(available[0], { policy: 'load-only' });
+    if (process.platform === 'win32') {
+      shared.ftsLoaded = true;
+    } else {
+      shared.ftsLoaded = await loadFTSExtension(available[0], { policy: 'load-only' });
+    }
   }
 
   pool.set(repoId, {
diff --git a/gitnexus/src/core/tree-sitter/safe-parse.ts b/gitnexus/src/core/tree-sitter/safe-parse.ts
new file mode 100644
index 000000000..1b3bc4fc5
--- /dev/null
+++ b/gitnexus/src/core/tree-sitter/safe-parse.ts
@@ -0,0 +1,40 @@
+import type Parser from 'tree-sitter';
+
+/**
+ * tree-sitter 0.21.x's Node native binding crashes (SIGSEGV) on Windows when
+ * `parser.parse(string, …)` is handed a JS string longer than 32 767 chars.
+ * The crash happens inside the binding's V8 string-to-buffer conversion and
+ * cannot be intercepted from JavaScript. The callback (`Parser.Input`) overload
+ * pulls source in fixed-size chunks via repeated callback invocations and
+ * bypasses that conversion path entirely.
+ *
+ * Chunk size is comfortably below the boundary; any value < 32 767 works.
+ */
+const SAFE_PARSE_CHUNK_CHARS = 16 * 1024;
+
+/**
+ * Files at or below this length skip the callback machinery and use the
+ * direct string overload — the bug only manifests above the int16 boundary,
+ * so small inputs save the cost of N callback invocations per parse.
+ */
+const DIRECT_PARSE_LIMIT_CHARS = 16 * 1024;
+
+/**
+ * Parse `sourceText` safely on every platform. See {@link SAFE_PARSE_CHUNK_CHARS}
+ * for the underlying tree-sitter binding bug this works around.
+ */
+export function parseSourceSafe(
+  parser: Parser,
+  sourceText: string,
+  oldTree?: Parser.Tree,
+  options?: Parser.Options,
+): Parser.Tree {
+  if (sourceText.length <= DIRECT_PARSE_LIMIT_CHARS) {
+    return parser.parse(sourceText, oldTree, options);
+  }
+  const input: Parser.Input = (index) => {
+    if (index >= sourceText.length) return null;
+    return sourceText.slice(index, index + SAFE_PARSE_CHUNK_CHARS);
+  };
+  return parser.parse(input, oldTree, options);
+}
diff --git a/gitnexus/test/helpers/parse-source-safe-mock.ts b/gitnexus/test/helpers/parse-source-safe-mock.ts
new file mode 100644
index 000000000..8cc0646a4
--- /dev/null
+++ b/gitnexus/test/helpers/parse-source-safe-mock.ts
@@ -0,0 +1,53 @@
+import { vi } from 'vitest';
+import type * as SafeParseModule from '../../src/core/tree-sitter/safe-parse.js';
+
+/**
+ * Build a vitest mock module for `gitnexus/src/core/tree-sitter/safe-parse.ts`
+ * that spies on `parseSourceSafe` while still delegating to the real
+ * implementation.
+ *
+ * Background: tests that feed >32 767-char inputs through extractors,
+ * chunkers, or any parse caller need to assert the call routed through
+ * `parseSourceSafe` rather than `parser.parse(string, ...)` directly. A
+ * direct call SIGSEGVs on Windows for inputs that size; on Linux/macOS it
+ * succeeds, so a "no throw" assertion alone silently passes with the
+ * bypass reintroduced. The spy assertion is what actually catches the
+ * regression.
+ *
+ * Why the test still has to call `vi.mock` with a literal path: vitest's
+ * hoister static-analyzes the first argument of `vi.mock`, and the path
+ * varies by directory depth across test files. Everything else — the
+ * `vi.importActual` round-trip, the spy installation, and the merged
+ * module shape — lives here.
+ *
+ * Why the test still has to dynamic-`import()` this helper inside the
+ * `vi.mock` factory: `vi.mock` is hoisted above static imports, so the
+ * factory closure cannot reference statically-imported helpers (they are
+ * uninitialized at hoist time). The factory body, however, is async and
+ * runs only when the mocked module is first consumed — by which point
+ * the helper resolves cleanly via dynamic `import()`.
+ *
+ * Usage:
+ *
+ *   const { parseSourceSafeSpy } = vi.hoisted(() => ({ parseSourceSafeSpy: vi.fn() }));
+ *
+ *   vi.mock('../../../src/core/tree-sitter/safe-parse.js', async () => {
+ *     const { buildSafeParseMock } = await import('../../helpers/parse-source-safe-mock.js');
+ *     return buildSafeParseMock(parseSourceSafeSpy);
+ *   });
+ *
+ *   it('routes large input through parseSourceSafe', async () => {
+ *     parseSourceSafeSpy.mockClear();
+ *     // ... call extractor with >40 000-char input ...
+ *     expect(parseSourceSafeSpy).toHaveBeenCalled();
+ *   });
+ */
+export async function buildSafeParseMock(
+  spy: ReturnType<typeof vi.fn>,
+): Promise<typeof SafeParseModule> {
+  const actual = await vi.importActual<typeof SafeParseModule>(
+    '../../src/core/tree-sitter/safe-parse.js',
+  );
+  spy.mockImplementation(actual.parseSourceSafe);
+  return { ...actual, parseSourceSafe: spy };
+}
diff --git a/gitnexus/test/unit/ast-utils.test.ts b/gitnexus/test/unit/ast-utils.test.ts
index f736d7e77..481ebc740 100644
--- a/gitnexus/test/unit/ast-utils.test.ts
+++ b/gitnexus/test/unit/ast-utils.test.ts
@@ -1,10 +1,11 @@
 import { beforeEach, describe, expect, it, vi } from 'vitest';
 
-const { createParserForLanguage, getLanguageFromFilename } = vi.hoisted(() => ({
+const { createParserForLanguage, getLanguageFromFilename, parseSourceSafeSpy } = vi.hoisted(() => ({
   createParserForLanguage: vi.fn(),
   getLanguageFromFilename: vi.fn((filePath: string) =>
     filePath.endsWith('.py') ? 'python' : 'typescript',
   ),
+  parseSourceSafeSpy: vi.fn(),
 }));
 
 vi.mock('../../src/core/tree-sitter/parser-loader.js', () => ({
@@ -15,6 +16,11 @@ vi.mock('../../src/core/tree-sitter/parser-loader.js', () => ({
   ),
 }));
 
+vi.mock('../../src/core/tree-sitter/safe-parse.js', async () => {
+  const { buildSafeParseMock } = await import('../helpers/parse-source-safe-mock.js');
+  return buildSafeParseMock(parseSourceSafeSpy);
+});
+
 vi.mock('gitnexus-shared', () => ({
   getLanguageFromFilename,
 }));
@@ -72,4 +78,25 @@ describe('ensureAndParse', () => {
     expect(tsParse).toHaveBeenCalledTimes(2);
     expect(tsxParse).toHaveBeenCalledTimes(1);
   });
+
+  // Windows SIGSEGV regression: ensureAndParse must route through parseSourceSafe
+  // so >32 767-char inputs do not crash the process. Direct parser.parse(content)
+  // on strings that size SIGSEGVs on Windows; the spy assertion is what catches
+  // a bypass since parser.parse(40 000 chars) succeeds on Linux/macOS.
+  it('routes >32 767-char input through parseSourceSafe', async () => {
+    parseSourceSafeSpy.mockClear();
+
+    const fakeParse = vi.fn().mockReturnValue({ rootNode: { type: 'module' } });
+    createParserForLanguage.mockResolvedValue({ parse: fakeParse });
+
+    const { ensureAndParse } = await import('../../src/core/embeddings/ast-utils.js');
+
+    const largeInput = 'const x = 1;\n'.repeat(4000); // ~52 000 chars
+    expect(largeInput.length).toBeGreaterThan(40_000);
+
+    const result = await ensureAndParse(largeInput, 'big.ts');
+
+    expect(parseSourceSafeSpy).toHaveBeenCalled();
+    expect(result).not.toBeNull();
+  });
 });
diff --git a/gitnexus/test/unit/group/grpc-extractor.test.ts b/gitnexus/test/unit/group/grpc-extractor.test.ts
index b128c6ddf..127dd6ab9 100644
--- a/gitnexus/test/unit/group/grpc-extractor.test.ts
+++ b/gitnexus/test/unit/group/grpc-extractor.test.ts
@@ -1,8 +1,15 @@
-import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
 import * as fs from 'node:fs';
 import fsp from 'node:fs/promises';
 import * as path from 'node:path';
 import * as os from 'node:os';
+
+const { parseSourceSafeSpy } = vi.hoisted(() => ({ parseSourceSafeSpy: vi.fn() }));
+
+vi.mock('../../../src/core/tree-sitter/safe-parse.js', async () => {
+  const { buildSafeParseMock } = await import('../../helpers/parse-source-safe-mock.js');
+  return buildSafeParseMock(parseSourceSafeSpy);
+});
 import {
   GrpcExtractor,
   buildProtoMap,
@@ -677,6 +684,33 @@ stub = leaked_pb2_grpc.LeakedServiceStub(channel)`,
       ).toBe(false);
     });
   });
+
+  describe('Windows SIGSEGV regression — large input must route through parseSourceSafe', () => {
+    it('routes >32 767-char source file through parseSourceSafe (not direct parser.parse)', async () => {
+      parseSourceSafeSpy.mockClear();
+
+      // Synthesize a >40 000-char source file in a language whose grpc plugin
+      // is always available (Go has no optional grammar — the Go plugin is
+      // unconditionally wired in grpc-patterns/index.ts). Direct
+      // parser.parse(content) on an input this size SIGSEGVs the process on
+      // Windows; parseSourceSafe routes through the chunked-callback path and
+      // works on every platform. The spy assertion is what catches the
+      // regression — a "no throw" assertion alone is satisfied by the bypass
+      // on Linux/macOS where parser.parse(40 000 chars) succeeds.
+      const padding = Array.from(
+        { length: 600 },
+        (_, i) => `func helper${i}() string { return "padding-${i}-aaaaaaaaaaaaaaaaaaaaaa" }\n`,
+      ).join('');
+      const largeGo = `package big\n\n${padding}\n`;
+      expect(largeGo.length).toBeGreaterThan(40_000);
+
+      writeFile('server/big.go', largeGo);
+
+      await extractor.extract(null, tmpDir, makeRepo(tmpDir));
+
+      expect(parseSourceSafeSpy).toHaveBeenCalled();
+    });
+  });
 });
 
 describe('buildProtoMap', () => {
diff --git a/gitnexus/test/unit/group/http-route-extractor.test.ts b/gitnexus/test/unit/group/http-route-extractor.test.ts
index 69d3da2fa..2e3b0d212 100644
--- a/gitnexus/test/unit/group/http-route-extractor.test.ts
+++ b/gitnexus/test/unit/group/http-route-extractor.test.ts
@@ -1,7 +1,15 @@
-import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
 import * as fs from 'node:fs';
 import * as path from 'node:path';
 import * as os from 'node:os';
+
+const { parseSourceSafeSpy } = vi.hoisted(() => ({ parseSourceSafeSpy: vi.fn() }));
+
+vi.mock('../../../src/core/tree-sitter/safe-parse.js', async () => {
+  const { buildSafeParseMock } = await import('../../helpers/parse-source-safe-mock.js');
+  return buildSafeParseMock(parseSourceSafeSpy);
+});
+
 import { HttpRouteExtractor } from '../../../src/core/group/extractors/http-route-extractor.js';
 import type { RepoHandle } from '../../../src/core/group/types.js';
 
@@ -815,4 +823,34 @@ export default r;
       expect(contracts.some((c) => c.symbolRef?.filePath?.startsWith('mentor_env/'))).toBe(false);
     });
   });
+
+  describe('Windows SIGSEGV regression — large input must route through parseSourceSafe', () => {
+    it('routes >32 767-char source file through parseSourceSafe (not direct parser.parse)', async () => {
+      parseSourceSafeSpy.mockClear();
+
+      // >40 000-char Java controller file. Direct parser.parse(content) on
+      // an input this size SIGSEGVs the process on Windows. The spy assertion
+      // is what catches the regression — a "no throw" assertion alone is
+      // satisfied by the bypass on Linux/macOS where parser.parse(40 000 chars)
+      // succeeds.
+      const padding = Array.from(
+        { length: 600 },
+        (_, i) => `    public String helper${i}() { return "padding-${i}-aaaaaaaaaaaaaaaaaaa"; }\n`,
+      ).join('');
+      const largeJava = `package com.example;\n\n@RestController\npublic class BigController {\n${padding}}\n`;
+      expect(largeJava.length).toBeGreaterThan(40_000);
+
+      // Use mkdtempSync rather than a fixed subdir name: satisfies CodeQL's
+      // js/insecure-temporary-file rule by generating a unique random suffix
+      // instead of relying on the parent tmpDir's predictable Date.now() name.
+      const dir = fs.mkdtempSync(path.join(tmpDir, 'large-input-'));
+      fs.mkdirSync(path.join(dir, 'src/controller'), { recursive: true });
+      fs.writeFileSync(path.join(dir, 'src/controller/BigController.java'), largeJava);
+
+      const mockDbExecutor = async (_query: string) => [];
+      await extractor.extract(mockDbExecutor, dir, makeRepo(dir));
+
+      expect(parseSourceSafeSpy).toHaveBeenCalled();
+    });
+  });
 });
diff --git a/gitnexus/test/unit/group/include-extractor.test.ts b/gitnexus/test/unit/group/include-extractor.test.ts
index 3956cd5f2..321773518 100644
--- a/gitnexus/test/unit/group/include-extractor.test.ts
+++ b/gitnexus/test/unit/group/include-extractor.test.ts
@@ -1,7 +1,15 @@
-import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
 import * as fs from 'node:fs';
 import * as path from 'node:path';
 import * as os from 'node:os';
+
+const { parseSourceSafeSpy } = vi.hoisted(() => ({ parseSourceSafeSpy: vi.fn() }));
+
+vi.mock('../../../src/core/tree-sitter/safe-parse.js', async () => {
+  const { buildSafeParseMock } = await import('../../helpers/parse-source-safe-mock.js');
+  return buildSafeParseMock(parseSourceSafeSpy);
+});
+
 import { IncludeExtractor } from '../../../src/core/group/extractors/include-extractor.js';
 import type { RepoHandle } from '../../../src/core/group/types.js';
 import { normalizeContractId } from '../../../src/core/group/matching.js';
@@ -560,4 +568,35 @@ int auto_main() { return 0; }`,
       }
     });
   });
+
+  describe('Windows SIGSEGV regression — large input must route through parseSourceSafe', () => {
+    it('routes >32 767-char header file through parseSourceSafe (not direct parser.parse)', async () => {
+      parseSourceSafeSpy.mockClear();
+
+      // Bump the file-size cap so the >40 000-char file isn't filtered before
+      // it ever reaches the parser. Direct parser.parse(content) on a string
+      // this size SIGSEGVs the process on Windows. The spy assertion catches
+      // the regression — a "no throw" assertion alone is satisfied by the
+      // bypass on Linux/macOS where parser.parse(40 000 chars) succeeds.
+      const previousLimit = process.env.GITNEXUS_MAX_FILE_SIZE;
+      process.env.GITNEXUS_MAX_FILE_SIZE = '512';
+      try {
+        const includes = Array.from(
+          { length: 1500 },
+          (_, i) => `#include "lib/header_${i}.h"\n`,
+        ).join('');
+        const largeHeader = `#pragma once\n${includes}\nstruct Big {};\n`;
+        expect(largeHeader.length).toBeGreaterThan(40_000);
+
+        writeFile('big/big.cpp', largeHeader);
+
+        await extractor.extract(null, tmpDir, makeRepo(tmpDir));
+
+        expect(parseSourceSafeSpy).toHaveBeenCalled();
+      } finally {
+        if (previousLimit === undefined) delete process.env.GITNEXUS_MAX_FILE_SIZE;
+        else process.env.GITNEXUS_MAX_FILE_SIZE = previousLimit;
+      }
+    });
+  });
 });
diff --git a/gitnexus/test/unit/group/thrift-extractor.test.ts b/gitnexus/test/unit/group/thrift-extractor.test.ts
index ca7045543..fa33b0e49 100644
--- a/gitnexus/test/unit/group/thrift-extractor.test.ts
+++ b/gitnexus/test/unit/group/thrift-extractor.test.ts
@@ -1,8 +1,16 @@
-import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
 import * as fs from 'node:fs';
 import fsp from 'node:fs/promises';
 import * as path from 'node:path';
 import * as os from 'node:os';
+
+const { parseSourceSafeSpy } = vi.hoisted(() => ({ parseSourceSafeSpy: vi.fn() }));
+
+vi.mock('../../../src/core/tree-sitter/safe-parse.js', async () => {
+  const { buildSafeParseMock } = await import('../../helpers/parse-source-safe-mock.js');
+  return buildSafeParseMock(parseSourceSafeSpy);
+});
+
 import {
   ThriftExtractor,
   buildThriftContext,
@@ -580,6 +588,39 @@ class PaymentWorkflow {
 
     expect(contracts).toEqual([]);
   });
+
+  describe('Windows SIGSEGV regression — large input must route through parseSourceSafe', () => {
+    it('routes >32 767-char source file through parseSourceSafe (not direct parser.parse)', async () => {
+      parseSourceSafeSpy.mockClear();
+
+      // Need a base .thrift file so buildThriftContext finds at least one
+      // service to scan; without it the source-scan loop short-circuits.
+      writeFile(
+        'idl/order.thrift',
+        `namespace java billing.v1
+service OrderService {
+  PlaceOrderResponse PlaceOrder(1: PlaceOrderRequest request)
+}`,
+      );
+
+      // >40 000-char Java client file. Direct parser.parse(content) on a
+      // string this size SIGSEGVs the process on Windows. The spy assertion
+      // catches the regression — a "no throw" assertion alone is satisfied
+      // by the bypass on Linux/macOS where parser.parse(40 000 chars) succeeds.
+      const padding = Array.from(
+        { length: 600 },
+        (_, i) => `    public String helper${i}() { return "padding-${i}-aaaaaaaaaaaaaaaaaaa"; }\n`,
+      ).join('');
+      const largeJava = `package com.example;\n\nimport billing.v1.OrderService;\n\npublic class BigClient {\n  private OrderService.Iface client;\n${padding}}\n`;
+      expect(largeJava.length).toBeGreaterThan(40_000);
+
+      writeFile('src/main/java/com/example/BigClient.java', largeJava);
+
+      await extractor.extract(null, tmpDir, makeRepo(tmpDir));
+
+      expect(parseSourceSafeSpy).toHaveBeenCalled();
+    });
+  });
 });
 
 describe('buildThriftContext', () => {
diff --git a/gitnexus/test/unit/safe-parse.test.ts b/gitnexus/test/unit/safe-parse.test.ts
new file mode 100644
index 000000000..e536bbd40
--- /dev/null
+++ b/gitnexus/test/unit/safe-parse.test.ts
@@ -0,0 +1,74 @@
+import { describe, it, expect } from 'vitest';
+import Parser from 'tree-sitter';
+import Python from 'tree-sitter-python';
+import { parseSourceSafe } from '../../src/core/tree-sitter/safe-parse.js';
+
+const makeParser = (): Parser => {
+  const p = new Parser();
+  p.setLanguage(Python);
+  return p;
+};
+
+const buildSource = (chars: number, lineLen = 80): string => {
+  const line = 'x = 1' + ' '.repeat(Math.max(0, lineLen - 6)) + '\n';
+  const lines = Math.ceil(chars / line.length);
+  return line.repeat(lines).slice(0, chars);
+};
+
+describe('parseSourceSafe', () => {
+  it('parses small ASCII sources via the direct path', () => {
+    const tree = parseSourceSafe(makeParser(), 'x = 1\n');
+    expect(tree.rootNode.type).toBe('module');
+    expect(tree.rootNode.hasError).toBe(false);
+  });
+
+  it('parses sources at the direct/callback boundary (16 KiB)', () => {
+    const src = buildSource(16 * 1024);
+    const tree = parseSourceSafe(makeParser(), src);
+    expect(tree.rootNode.hasError).toBe(false);
+    expect(tree.rootNode.endIndex).toBe(src.length);
+  });
+
+  it('parses sources just above the boundary via the callback path', () => {
+    const src = buildSource(16 * 1024 + 1);
+    const tree = parseSourceSafe(makeParser(), src);
+    expect(tree.rootNode.hasError).toBe(false);
+    expect(tree.rootNode.endIndex).toBe(src.length);
+  });
+
+  it('parses sources at and around the 32 767-char Windows crash boundary', () => {
+    for (const len of [32_766, 32_767, 32_768]) {
+      const src = buildSource(len);
+      const tree = parseSourceSafe(makeParser(), src);
+      expect(tree.rootNode.hasError, `len=${len}`).toBe(false);
+      expect(tree.rootNode.endIndex, `len=${len}`).toBe(src.length);
+    }
+  });
+
+  it('parses a single line longer than the chunk size (no newlines)', () => {
+    const src = '"' + 'a'.repeat(20_000) + '"\n';
+    const tree = parseSourceSafe(makeParser(), src);
+    expect(tree.rootNode.hasError).toBe(false);
+    expect(tree.rootNode.endIndex).toBe(src.length);
+  });
+
+  it('parses sources with CRLF line endings near a chunk boundary', () => {
+    const line = 'x = 1' + ' '.repeat(75) + '\r\n';
+    const src = line.repeat(Math.ceil(20_000 / line.length));
+    const tree = parseSourceSafe(makeParser(), src);
+    expect(tree.rootNode.hasError).toBe(false);
+    expect(tree.rootNode.endIndex).toBe(src.length);
+  });
+
+  it('parses a large all-non-ASCII source identically to the direct path', () => {
+    const small = '# ' + '漢'.repeat(50) + '\n';
+    const direct = makeParser().parse(small);
+    const safe = parseSourceSafe(makeParser(), small);
+    expect(safe.rootNode.toString()).toBe(direct.rootNode.toString());
+
+    const large = ('# ' + '漢'.repeat(8_000) + '\n').repeat(3);
+    const tree = parseSourceSafe(makeParser(), large);
+    expect(tree.rootNode.hasError).toBe(false);
+    expect(tree.rootNode.endIndex).toBe(large.length);
+  });
+});