diff --git a/extensions/vscode/src/dap/adapter.ts b/extensions/vscode/src/dap/adapter.ts
index ed1e2595..38589e03 100644
--- a/extensions/vscode/src/dap/adapter.ts
+++ b/extensions/vscode/src/dap/adapter.ts
@@ -78,6 +78,8 @@ type BreakpointSyncLogRecord = {
   error?: string;
 };
 
+const BREAKPOINT_SYNC_TEST_LOG_ENV = 'SOROBAN_DEBUG_BREAKPOINT_SYNC_TEST_LOG';
+
 export class SorobanDebugSession extends DebugSession {
   private static readonly FIRST_CONTINUE_STOP_REASON: 'breakpoint' = 'breakpoint';
   private logManager: LogManager | undefined;
@@ -865,6 +867,7 @@ export class SorobanDebugSession extends DebugSession {
           LogPhase.DAP,
           `BREAKPOINT_SYNC ${JSON.stringify(setRecord)}`
         );
+        this.emitBreakpointSyncTestLog(setRecord);
       } catch (error) {
         const errorMessage = error instanceof Error ? error.message : String(error);
         errors.set(
@@ -890,6 +893,15 @@ export class SorobanDebugSession extends DebugSession {
     return errors;
   }
 
+  private emitBreakpointSyncTestLog(record: BreakpointSyncLogRecord): void {
+    if (process.env[BREAKPOINT_SYNC_TEST_LOG_ENV] !== '1' || record.action !== 'set' || !record.success) {
+      return;
+    }
+
+    // Temporary stderr log for e2e regression coverage of heuristic breakpoint sync.
+    process.stderr.write(`BREAKPOINT_SYNC_TEST ${JSON.stringify(record)}\n`);
+  }
+
   private async refreshState(): Promise<void> {
     if (!this.debuggerProcess) {
       return;
diff --git a/extensions/vscode/src/test/runTest.ts b/extensions/vscode/src/test/runTest.ts
index cf3b5799..0ceb97fc 100644
--- a/extensions/vscode/src/test/runTest.ts
+++ b/extensions/vscode/src/test/runTest.ts
@@ -27,6 +27,8 @@ type DebugMessage = {
   response?: { type: string; [key: string]: unknown };
 };
 
+const BREAKPOINT_SYNC_TEST_LOG_ENV = "SOROBAN_DEBUG_BREAKPOINT_SYNC_TEST_LOG";
+
 async function startMockDebuggerServer(options: {
   evaluateDelayMs: number;
 }): Promise<{ port: number; close: () => Promise<void> }> {
@@ -163,6 +165,36 @@ async function wait(ms: number): Promise<void> {
   await new Promise<void>((resolve) => setTimeout(resolve, ms));
 }
 
+async function waitForProcessLog(
+  getOutput: () => string,
+  pattern: RegExp,
+  timeoutMs = 5_000,
+): Promise<string> {
+  const deadline = Date.now() + timeoutMs;
+  while (Date.now() < deadline) {
+    const output = getOutput();
+    if (pattern.test(output)) {
+      return output;
+    }
+    await wait(25);
+  }
+
+  throw new Error(`Timed out waiting for process log matching ${pattern}`);
+}
+
+async function assertProcessLogAbsent(
+  getOutput: () => string,
+  pattern: RegExp,
+  waitMs = 500,
+): Promise<void> {
+  await wait(waitMs);
+  assert.doesNotMatch(
+    getOutput(),
+    pattern,
+    `Did not expect process log matching ${pattern}`,
+  );
+}
+
 async function main(): Promise<void> {
   if (!(await isLoopbackAvailable())) {
     console.warn(
@@ -756,7 +788,7 @@ async function main(): Promise<void> {
   const exportedFunctions = await debuggerProcess.getContractFunctions();
   const resolvedBreakpoints = resolveSourceBreakpoints(
     sourcePath,
-    [10],
+    [14],
     exportedFunctions,
   );
   assert.equal(
@@ -771,10 +803,36 @@ async function main(): Promise<void> {
     "Expected heuristic mapping to still set a function breakpoint",
   );
 
+  const nonExportedBreakpoints = resolveSourceBreakpoints(
+    sourcePath,
+    [10],
+    exportedFunctions,
+  );
+  assert.equal(
+    nonExportedBreakpoints[0].verified,
+    false,
+    "Expected non-exported function mapping to be unverified",
+  );
+  assert.equal(
+    nonExportedBreakpoints[0].functionName,
+    "helper",
+    "Expected non-exported function line to map to helper",
+  );
+  assert.equal(
+    nonExportedBreakpoints[0].reasonCode,
+    "HEURISTIC_NOT_EXPORTED",
+    "Expected non-exported function reason code",
+  );
+  assert.equal(
+    nonExportedBreakpoints[0].setBreakpoint,
+    false,
+    "Expected non-exported function mapping to skip runtime breakpoint install",
+  );
+
   // Test HEURISTIC_NO_FUNCTION behavior for lines outside any function
   const noFunctionBreakpoints = resolveSourceBreakpoints(
     sourcePath,
-    [1, 2, 13], // Lines outside any function in lib.rs
+    [1, 2, 12, 16], // Lines outside any function in lib.rs
     exportedFunctions,
   );
 
@@ -934,9 +992,15 @@ async function runDapHappyPathE2E(
   fixtures: { contractPath: string; sourcePath: string; binaryPath: string },
 ): Promise<void> {
   const proc = spawn(process.execPath, [debugAdapterPath], {
+    env: { ...process.env, [BREAKPOINT_SYNC_TEST_LOG_ENV]: "1" },
     stdio: ["pipe", "pipe", "pipe"],
   });
   const client = new DapClient(proc);
+  let stderrOutput = "";
+  proc.stderr.setEncoding("utf8");
+  proc.stderr.on("data", (chunk: string) => {
+    stderrOutput += chunk;
+  });
 
   try {
     const init = await client.request("initialize", {
@@ -974,7 +1038,7 @@ async function runDapHappyPathE2E(
 
     const setBps = await client.request("setBreakpoints", {
       source: { path: fixtures.sourcePath },
-      breakpoints: [{ line: 10 }],
+      breakpoints: [{ line: 14 }],
     });
     assert.equal(
       setBps.success,
@@ -986,6 +1050,44 @@ async function runDapHappyPathE2E(
       false,
       "Expected heuristic source mapping to be unverified",
     );
+    const breakpointSyncLog = await waitForProcessLog(
+      () => stderrOutput,
+      /BREAKPOINT_SYNC_TEST .*"action":"set".*"functionName":"echo".*"success":true/,
+    );
+    assert.match(
+      breakpointSyncLog,
+      /BREAKPOINT_SYNC_TEST/,
+      "Expected adapter test log to confirm runtime breakpoint installation",
+    );
+
+    const privateBps = await client.request("setBreakpoints", {
+      source: { path: fixtures.sourcePath },
+      breakpoints: [{ line: 10 }],
+    });
+    assert.equal(
+      privateBps.success,
+      true,
+      `setBreakpoints for non-exported function failed: ${privateBps.message || ""}`,
+    );
+    assert.equal(
+      privateBps.body?.breakpoints?.[0]?.verified,
+      false,
+      "Expected non-exported function source mapping to be unverified",
+    );
+    assert.equal(
+      privateBps.body?.breakpoints?.[0]?.reasonCode,
+      "HEURISTIC_NOT_EXPORTED",
+      "Expected non-exported reason code on source breakpoint response",
+    );
+    assert.match(
+      String(privateBps.body?.breakpoints?.[0]?.message || ""),
+      /HEURISTIC_NOT_EXPORTED/,
+      "Expected non-exported breakpoint message to include reason code",
+    );
+    await assertProcessLogAbsent(
+      () => stderrOutput,
+      /BREAKPOINT_SYNC_TEST .*"action":"set".*"functionName":"helper".*"success":true/,
+    );
 
     const configDone = await client.request("configurationDone", {});
     assert.equal(
diff --git a/extensions/vscode/src/test/suites.ts b/extensions/vscode/src/test/suites.ts
index 5aaa2eec..2d71a3bf 100644
--- a/extensions/vscode/src/test/suites.ts
+++ b/extensions/vscode/src/test/suites.ts
@@ -28,6 +28,8 @@ type TestFixtures = {
   binaryPath: string;
 };
 
+const BREAKPOINT_SYNC_TEST_LOG_ENV = "SOROBAN_DEBUG_BREAKPOINT_SYNC_TEST_LOG";
+
 async function startMockDebuggerServer(options: {
   evaluateDelayMs: number;
 }): Promise<{ port: number; close: () => Promise<void> }> {
@@ -164,6 +166,36 @@ async function wait(ms: number): Promise<void> {
   await new Promise<void>((resolve) => setTimeout(resolve, ms));
 }
 
+async function waitForProcessLog(
+  getOutput: () => string,
+  pattern: RegExp,
+  timeoutMs = 5_000,
+): Promise<string> {
+  const deadline = Date.now() + timeoutMs;
+  while (Date.now() < deadline) {
+    const output = getOutput();
+    if (pattern.test(output)) {
+      return output;
+    }
+    await wait(25);
+  }
+
+  throw new Error(`Timed out waiting for process log matching ${pattern}`);
+}
+
+async function assertProcessLogAbsent(
+  getOutput: () => string,
+  pattern: RegExp,
+  waitMs = 500,
+): Promise<void> {
+  await wait(waitMs);
+  assert.doesNotMatch(
+    getOutput(),
+    pattern,
+    `Did not expect process log matching ${pattern}`,
+  );
+}
+
 function resolveFixtures(): TestFixtures {
   const extensionRoot = process.cwd();
   const repoRoot = path.resolve(extensionRoot, "..", "..");
@@ -546,7 +578,7 @@ export async function runSmokeSuite(): Promise<void> {
   const exportedFunctions = await debuggerProcess.getContractFunctions();
   const resolvedBreakpoints = resolveSourceBreakpoints(
     fixtures.sourcePath,
-    [10],
+    [14],
     exportedFunctions,
   );
   assert.equal(
@@ -561,10 +593,36 @@ export async function runSmokeSuite(): Promise<void> {
     "Expected heuristic mapping to still set a function breakpoint",
   );
 
+  const nonExportedBreakpoints = resolveSourceBreakpoints(
+    fixtures.sourcePath,
+    [10],
+    exportedFunctions,
+  );
+  assert.equal(
+    nonExportedBreakpoints[0].verified,
+    false,
+    "Expected non-exported function mapping to be unverified",
+  );
+  assert.equal(
+    nonExportedBreakpoints[0].functionName,
+    "helper",
+    "Expected non-exported function line to map to helper",
+  );
+  assert.equal(
+    nonExportedBreakpoints[0].reasonCode,
+    "HEURISTIC_NOT_EXPORTED",
+    "Expected non-exported function reason code",
+  );
+  assert.equal(
+    nonExportedBreakpoints[0].setBreakpoint,
+    false,
+    "Expected non-exported function mapping to skip runtime breakpoint install",
+  );
+
   // Test HEURISTIC_NO_FUNCTION behavior for lines outside any function
   const noFunctionBreakpoints = resolveSourceBreakpoints(
     fixtures.sourcePath,
-    [1, 2, 13], // Lines outside any function in lib.rs
+    [1, 2, 12, 16], // Lines outside any function in lib.rs
     exportedFunctions,
   );
 
@@ -740,9 +798,15 @@ async function runDapHappyPathE2E(
   fixtures: Pick<TestFixtures, "contractPath" | "sourcePath" | "binaryPath">,
 ): Promise<void> {
   const proc = spawn(process.execPath, [debugAdapterPath], {
+    env: { ...process.env, [BREAKPOINT_SYNC_TEST_LOG_ENV]: "1" },
     stdio: ["pipe", "pipe", "pipe"],
   });
   const client = new DapClient(proc);
+  let stderrOutput = "";
+  proc.stderr.setEncoding("utf8");
+  proc.stderr.on("data", (chunk: string) => {
+    stderrOutput += chunk;
+  });
 
   try {
     const init = await client.request("initialize", {
@@ -780,7 +844,7 @@ async function runDapHappyPathE2E(
 
     const setBps = await client.request("setBreakpoints", {
       source: { path: fixtures.sourcePath },
-      breakpoints: [{ line: 10 }],
+      breakpoints: [{ line: 14 }],
     });
     assert.equal(
       setBps.success,
@@ -802,6 +866,44 @@ async function runDapHappyPathE2E(
       /HEURISTIC_NO_DWARF/,
       "Expected breakpoint message to include heuristic reason code",
     );
+    const breakpointSyncLog = await waitForProcessLog(
+      () => stderrOutput,
+      /BREAKPOINT_SYNC_TEST .*"action":"set".*"functionName":"echo".*"success":true/,
+    );
+    assert.match(
+      breakpointSyncLog,
+      /BREAKPOINT_SYNC_TEST/,
+      "Expected adapter test log to confirm runtime breakpoint installation",
+    );
+
+    const privateBps = await client.request("setBreakpoints", {
+      source: { path: fixtures.sourcePath },
+      breakpoints: [{ line: 10 }],
+    });
+    assert.equal(
+      privateBps.success,
+      true,
+      `setBreakpoints for non-exported function failed: ${privateBps.message || ""}`,
+    );
+    assert.equal(
+      privateBps.body?.breakpoints?.[0]?.verified,
+      false,
+      "Expected non-exported function source mapping to be unverified",
+    );
+    assert.equal(
+      privateBps.body?.breakpoints?.[0]?.reasonCode,
+      "HEURISTIC_NOT_EXPORTED",
+      "Expected non-exported reason code on source breakpoint response",
+    );
+    assert.match(
+      String(privateBps.body?.breakpoints?.[0]?.message || ""),
+      /HEURISTIC_NOT_EXPORTED/,
+      "Expected non-exported breakpoint message to include reason code",
+    );
+    await assertProcessLogAbsent(
+      () => stderrOutput,
+      /BREAKPOINT_SYNC_TEST .*"action":"set".*"functionName":"helper".*"success":true/,
+    );
 
     const configDone = await client.request("configurationDone", {});
     assert.equal(
diff --git a/tests/fixtures/contracts/echo/src/lib.rs b/tests/fixtures/contracts/echo/src/lib.rs
index 9ac00734..fdd1035b 100644
--- a/tests/fixtures/contracts/echo/src/lib.rs
+++ b/tests/fixtures/contracts/echo/src/lib.rs
@@ -6,7 +6,11 @@ pub struct Echo;
 
 #[contractimpl]
 impl Echo {
-    pub fn echo(_env: Env, v: Val) -> Val {
+    fn helper(v: Val) -> Val {
         v
     }
+
+    pub fn echo(_env: Env, v: Val) -> Val {
+        Self::helper(v)
+    }
 }