diff --git a/packages/shared/src/validators/approval.test.ts b/packages/shared/src/validators/approval.test.ts
new file mode 100644
index 00000000..051d29b2
--- /dev/null
+++ b/packages/shared/src/validators/approval.test.ts
@@ -0,0 +1,31 @@
+import { describe, expect, it } from "vitest";
+import {
+  addApprovalCommentSchema,
+  requestApprovalRevisionSchema,
+  resolveApprovalSchema,
+} from "./approval.js";
+
+describe("approval validators", () => {
+  it("passes real line breaks through unchanged", () => {
+    expect(addApprovalCommentSchema.parse({ body: "Looks good\n\nApproved." }).body)
+      .toBe("Looks good\n\nApproved.");
+    expect(resolveApprovalSchema.parse({ decisionNote: "Decision\n\nApproved." }).decisionNote)
+      .toBe("Decision\n\nApproved.");
+  });
+
+  it("accepts null and omitted optional decision notes", () => {
+    expect(resolveApprovalSchema.parse({ decisionNote: null }).decisionNote).toBeNull();
+    expect(resolveApprovalSchema.parse({}).decisionNote).toBeUndefined();
+    expect(requestApprovalRevisionSchema.parse({ decisionNote: null }).decisionNote).toBeNull();
+    expect(requestApprovalRevisionSchema.parse({}).decisionNote).toBeUndefined();
+  });
+
+  it("normalizes escaped line breaks in approval comments and decision notes", () => {
+    expect(addApprovalCommentSchema.parse({ body: "Looks good\\n\\nApproved." }).body)
+      .toBe("Looks good\n\nApproved.");
+    expect(resolveApprovalSchema.parse({ decisionNote: "Decision\\n\\nApproved." }).decisionNote)
+      .toBe("Decision\n\nApproved.");
+    expect(requestApprovalRevisionSchema.parse({ decisionNote: "Decision\\r\\nRevise." }).decisionNote)
+      .toBe("Decision\nRevise.");
+  });
+});
diff --git a/packages/shared/src/validators/approval.ts b/packages/shared/src/validators/approval.ts
index ae6b2eb3..ca704795 100644
--- a/packages/shared/src/validators/approval.ts
+++ b/packages/shared/src/validators/approval.ts
@@ -1,5 +1,6 @@
 import { z } from "zod";
 import { APPROVAL_TYPES } from "../constants.js";
+import { multilineTextSchema } from "./text.js";
 
 export const createApprovalSchema = z.object({
   type: z.enum(APPROVAL_TYPES),
@@ -11,13 +12,13 @@ export const createApprovalSchema = z.object({
 export type CreateApproval = z.infer<typeof createApprovalSchema>;
 
 export const resolveApprovalSchema = z.object({
-  decisionNote: z.string().optional().nullable(),
+  decisionNote: multilineTextSchema.optional().nullable(),
 });
 
 export type ResolveApproval = z.infer<typeof resolveApprovalSchema>;
 
 export const requestApprovalRevisionSchema = z.object({
-  decisionNote: z.string().optional().nullable(),
+  decisionNote: multilineTextSchema.optional().nullable(),
 });
 
 export type RequestApprovalRevision = z.infer<typeof requestApprovalRevisionSchema>;
@@ -29,7 +30,7 @@ export const resubmitApprovalSchema = z.object({
 export type ResubmitApproval = z.infer<typeof resubmitApprovalSchema>;
 
 export const addApprovalCommentSchema = z.object({
-  body: z.string().min(1),
+  body: multilineTextSchema.pipe(z.string().min(1)),
 });
 
 export type AddApprovalComment = z.infer<typeof addApprovalCommentSchema>;
diff --git a/packages/shared/src/validators/issue.test.ts b/packages/shared/src/validators/issue.test.ts
new file mode 100644
index 00000000..4fa908e4
--- /dev/null
+++ b/packages/shared/src/validators/issue.test.ts
@@ -0,0 +1,78 @@
+import { describe, expect, it } from "vitest";
+import {
+  addIssueCommentSchema,
+  createIssueSchema,
+  respondIssueThreadInteractionSchema,
+  suggestedTaskDraftSchema,
+  updateIssueSchema,
+  upsertIssueDocumentSchema,
+} from "./issue.js";
+
+describe("issue validators", () => {
+  it("passes real line breaks through unchanged", () => {
+    const parsed = createIssueSchema.parse({
+      title: "Follow up PR",
+      description: "Line 1\n\nLine 2",
+    });
+
+    expect(parsed.description).toBe("Line 1\n\nLine 2");
+  });
+
+  it("accepts null and omitted optional multiline issue fields", () => {
+    expect(createIssueSchema.parse({ title: "Follow up PR", description: null }).description)
+      .toBeNull();
+    expect(createIssueSchema.parse({ title: "Follow up PR" }).description)
+      .toBeUndefined();
+    expect(updateIssueSchema.parse({ comment: undefined }).comment)
+      .toBeUndefined();
+  });
+
+  it("normalizes JSON-escaped line breaks in issue descriptions", () => {
+    const parsed = createIssueSchema.parse({
+      title: "Follow up PR",
+      description: "PR: https://example.com/pr/1\\n\\nShip the follow-up.",
+    });
+
+    expect(parsed.description).toBe("PR: https://example.com/pr/1\n\nShip the follow-up.");
+  });
+
+  it("normalizes escaped line breaks in issue update comments", () => {
+    const parsed = updateIssueSchema.parse({
+      comment: "Done\\n\\n- Verified the route",
+    });
+
+    expect(parsed.comment).toBe("Done\n\n- Verified the route");
+  });
+
+  it("normalizes escaped line breaks in issue comment bodies", () => {
+    const parsed = addIssueCommentSchema.parse({
+      body: "Progress update\\r\\n\\r\\nNext action.",
+    });
+
+    expect(parsed.body).toBe("Progress update\n\nNext action.");
+  });
+
+  it("normalizes escaped line breaks in generated task drafts", () => {
+    const parsed = suggestedTaskDraftSchema.parse({
+      clientKey: "task-1",
+      title: "Follow up",
+      description: "Line 1\\n\\nLine 2",
+    });
+
+    expect(parsed.description).toBe("Line 1\n\nLine 2");
+  });
+
+  it("normalizes escaped line breaks in thread summaries and documents", () => {
+    const response = respondIssueThreadInteractionSchema.parse({
+      answers: [],
+      summaryMarkdown: "Summary\\n\\nNext action",
+    });
+    const document = upsertIssueDocumentSchema.parse({
+      format: "markdown",
+      body: "# Plan\\n\\nShip it",
+    });
+
+    expect(response.summaryMarkdown).toBe("Summary\n\nNext action");
+    expect(document.body).toBe("# Plan\n\nShip it");
+  });
+});
diff --git a/packages/shared/src/validators/issue.ts b/packages/shared/src/validators/issue.ts
index b4451cf9..d8f58a83 100644
--- a/packages/shared/src/validators/issue.ts
+++ b/packages/shared/src/validators/issue.ts
@@ -10,6 +10,7 @@ import {
   ISSUE_THREAD_INTERACTION_KINDS,
   ISSUE_THREAD_INTERACTION_STATUSES,
 } from "../constants.js";
+import { multilineTextSchema } from "./text.js";
 
 export const ISSUE_EXECUTION_WORKSPACE_PREFERENCES = [
   "inherit",
@@ -130,7 +131,7 @@ export const createIssueSchema = z.object({
   blockedByIssueIds: z.array(z.string().uuid()).optional(),
   inheritExecutionWorkspaceFromIssueId: z.string().uuid().optional().nullable(),
   title: z.string().min(1),
-  description: z.string().optional().nullable(),
+  description: multilineTextSchema.optional().nullable(),
   status: z.enum(ISSUE_STATUSES).optional().default("backlog"),
   priority: z.enum(ISSUE_PRIORITIES).optional().default("medium"),
   assigneeAgentId: z.string().uuid().optional().nullable(),
@@ -168,7 +169,7 @@ export type CreateIssueLabel = z.infer<typeof createIssueLabelSchema>;
 
 export const updateIssueSchema = createIssueSchema.partial().extend({
   assigneeAgentId: z.string().trim().min(1).optional().nullable(),
-  comment: z.string().min(1).optional(),
+  comment: multilineTextSchema.pipe(z.string().min(1)).optional(),
   reviewRequest: issueReviewRequestSchema.optional().nullable(),
   reopen: z.boolean().optional(),
   resume: z.boolean().optional(),
@@ -187,7 +188,7 @@ export const checkoutIssueSchema = z.object({
 export type CheckoutIssue = z.infer<typeof checkoutIssueSchema>;
 
 export const addIssueCommentSchema = z.object({
-  body: z.string().min(1),
+  body: multilineTextSchema.pipe(z.string().min(1)),
   reopen: z.boolean().optional(),
   resume: z.boolean().optional(),
   interrupt: z.boolean().optional(),
@@ -213,7 +214,7 @@ export const suggestedTaskDraftSchema = z.object({
   parentClientKey: z.string().trim().min(1).max(120).nullable().optional(),
   parentId: z.string().uuid().nullable().optional(),
   title: z.string().trim().min(1).max(240),
-  description: z.string().trim().max(20000).nullable().optional(),
+  description: multilineTextSchema.pipe(z.string().trim().max(20000)).nullable().optional(),
   priority: z.enum(ISSUE_PRIORITIES).nullable().optional(),
   assigneeAgentId: z.string().uuid().nullable().optional(),
   assigneeUserId: z.string().trim().min(1).nullable().optional(),
@@ -439,7 +440,7 @@ export type RejectIssueThreadInteraction = z.infer<typeof rejectIssueThreadInter
 
 export const respondIssueThreadInteractionSchema = z.object({
   answers: z.array(askUserQuestionsAnswerSchema).max(20),
-  summaryMarkdown: z.string().max(20000).nullable().optional(),
+  summaryMarkdown: multilineTextSchema.pipe(z.string().max(20000)).nullable().optional(),
 });
 export type RespondIssueThreadInteraction = z.infer<typeof respondIssueThreadInteractionSchema>;
 
@@ -462,7 +463,7 @@ export const issueDocumentFormatSchema = z.enum(ISSUE_DOCUMENT_FORMATS);
 export const upsertIssueDocumentSchema = z.object({
   title: z.string().trim().max(200).nullable().optional(),
   format: issueDocumentFormatSchema,
-  body: z.string().max(524288),
+  body: multilineTextSchema.pipe(z.string().max(524288)),
   changeSummary: z.string().trim().max(500).nullable().optional(),
   baseRevisionId: z.string().uuid().nullable().optional(),
 });
diff --git a/packages/shared/src/validators/text.ts b/packages/shared/src/validators/text.ts
new file mode 100644
index 00000000..322597a9
--- /dev/null
+++ b/packages/shared/src/validators/text.ts
@@ -0,0 +1,10 @@
+import { z } from "zod";
+
+export function normalizeEscapedLineBreaks(value: string): string {
+  return value
+    .replace(/\\r\\n/g, "\n")
+    .replace(/\\n/g, "\n")
+    .replace(/\\r/g, "\n");
+}
+
+export const multilineTextSchema = z.string().transform(normalizeEscapedLineBreaks);