diff --git a/actions/setup/js/apply_samples.cjs b/actions/setup/js/apply_samples.cjs
index 10d2a91b1ab..8481fc2e60b 100644
--- a/actions/setup/js/apply_samples.cjs
+++ b/actions/setup/js/apply_samples.cjs
@@ -248,16 +248,30 @@ async function derivePrHeadRef(entry) {
     if (ref) return ref;
   }
 
-  // 3. Explicit pull_request_number on the sample arguments.
-  const argNumber = Number(entry.arguments.pull_request_number);
-  if (Number.isFinite(argNumber) && argNumber > 0) {
-    const ref = await fetchPullRequestHeadRef({ owner, repo, pullNumber: argNumber });
+  // 3. PR number from sample arguments, workflow_dispatch inputs, or config target.
+  const pullNumber =
+    toPositivePullRequestNumber(entry.arguments.pull_request_number) ||
+    toPositivePullRequestNumber(payload?.inputs?.pull_request_number) ||
+    toPositivePullRequestNumber(payload?.client_payload?.pull_request_number) ||
+    readConfiguredTargetPullRequestNumber(entry.tool);
+  if (pullNumber) {
+    const ref = await fetchPullRequestHeadRef({ owner, repo, pullNumber });
     if (ref) return ref;
   }
 
   return null;
 }
 
+/**
+ * Convert unknown value to a positive pull request number, or null.
+ * @param {any} value
+ * @returns {number|null}
+ */
+function toPositivePullRequestNumber(value) {
+  const n = Number(value);
+  return Number.isFinite(n) && n > 0 ? n : null;
+}
+
 /**
  * Read the configured `target-repo` for a given safe-output tool from the
  * safe-outputs config file (GH_AW_SAFE_OUTPUTS_CONFIG_PATH). Returns an empty
@@ -291,6 +305,44 @@ function readConfiguredTargetRepo(tool) {
   return "";
 }
 
+/**
+ * Read configured `target` for a safe-output tool and coerce it into a PR number.
+ * Supports plain numeric values and `${ENV_VAR}` placeholders.
+ * @param {string} tool
+ * @returns {number|null}
+ */
+function readConfiguredTargetPullRequestNumber(tool) {
+  const configPath = process.env.GH_AW_SAFE_OUTPUTS_CONFIG_PATH;
+  if (!configPath || !configPath.trim()) {
+    return null;
+  }
+
+  const toolKey = typeof tool === "string" ? tool.replace(/-/g, "_") : "";
+
+  try {
+    const raw = fs.readFileSync(configPath, "utf8");
+    const parsed = JSON.parse(raw);
+    const config = parsed && typeof parsed === "object" ? Object.fromEntries(Object.entries(parsed).map(([k, v]) => [String(k).replace(/-/g, "_"), v])) : {};
+    const toolConfig = toolKey && config && typeof config === "object" ? config[toolKey] : null;
+    const target = toolConfig && typeof toolConfig === "object" ? toolConfig.target : null;
+
+    if (typeof target === "number") {
+      return toPositivePullRequestNumber(target);
+    }
+    if (typeof target === "string") {
+      const trimmed = target.trim();
+      const envMatch = /^\$\{([A-Za-z_][A-Za-z0-9_]*)\}$/.exec(trimmed);
+      if (envMatch) {
+        return toPositivePullRequestNumber(process.env[envMatch[1]]);
+      }
+      return toPositivePullRequestNumber(trimmed);
+    }
+  } catch (err) {
+    core.debug(`apply_samples: could not read target from ${configPath}: ${getErrorMessage(err)}`);
+  }
+  return null;
+}
+
 /**
  * Resolve the on-disk working directory in which a sample's patch should be
  * staged (branch created + patch committed).
diff --git a/actions/setup/js/apply_samples.test.cjs b/actions/setup/js/apply_samples.test.cjs
index 3391abdd40d..6e28f472c20 100644
--- a/actions/setup/js/apply_samples.test.cjs
+++ b/actions/setup/js/apply_samples.test.cjs
@@ -504,6 +504,51 @@ describe("apply_samples.cjs preStagePatch (create_pull_request / push_to_pull_re
     }
   });
 
+  it("derives push_to_pull_request_branch branch from workflow_dispatch inputs.pull_request_number", async () => {
+    const workspace = makeTempDir("gh-aw-prestage-push-dispatch-input-");
+    initRepo(workspace, "main");
+
+    const headRef = "feat/dispatch-pr-number";
+    const fetchSpy = vi.spyOn(globalThis, "fetch").mockResolvedValueOnce({
+      ok: true,
+      status: 200,
+      json: async () => ({ head: { ref: headRef } }),
+    });
+
+    const eventPath = path.join(workspace, "event.json");
+    fs.writeFileSync(
+      eventPath,
+      JSON.stringify({
+        inputs: { pull_request_number: "123" },
+      })
+    );
+
+    const prevBase = process.env.GH_AW_CUSTOM_BASE_BRANCH;
+    const prevEvent = process.env.GITHUB_EVENT_PATH;
+    const prevRepo = process.env.GITHUB_REPOSITORY;
+    process.env.GH_AW_CUSTOM_BASE_BRANCH = "main";
+    process.env.GITHUB_EVENT_PATH = eventPath;
+    process.env.GITHUB_REPOSITORY = "owner/repo";
+    try {
+      const entry = {
+        tool: "push_to_pull_request_branch",
+        arguments: { message: "Push update" },
+        sidecars: { patch: newFileDiff("dispatch-input.txt", "via workflow_dispatch input\n") },
+      };
+      await preStagePatch(entry, 0, workspace);
+      expect(git(["rev-parse", "--abbrev-ref", "HEAD"], workspace).trim()).toBe(headRef);
+      expect(fetchSpy).toHaveBeenCalledWith(expect.stringContaining("/repos/owner/repo/pulls/123"), expect.anything());
+    } finally {
+      fetchSpy.mockRestore();
+      if (prevBase === undefined) delete process.env.GH_AW_CUSTOM_BASE_BRANCH;
+      else process.env.GH_AW_CUSTOM_BASE_BRANCH = prevBase;
+      if (prevEvent === undefined) delete process.env.GITHUB_EVENT_PATH;
+      else process.env.GITHUB_EVENT_PATH = prevEvent;
+      if (prevRepo === undefined) delete process.env.GITHUB_REPOSITORY;
+      else process.env.GITHUB_REPOSITORY = prevRepo;
+    }
+  });
+
   it("derives push_to_pull_request_branch branch from explicit arguments.pull_request_number when no event payload exists", async () => {
     // Resolution path 3: no GITHUB_EVENT_PATH, but the sample entry carries an
     // explicit `arguments.pull_request_number`. The driver should hit the PR