diff --git a/docs/error-handling.md b/docs/error-handling.md
index 6792a6c5..fb17a850 100644
--- a/docs/error-handling.md
+++ b/docs/error-handling.md
@@ -15,7 +15,8 @@ CLIError (abstract base class)
 │   ├── ConfigInvalidError     # Invalid config syntax/structure
 │   ├── ConfigExistsError      # Project already exists
 │   ├── SchemaValidationError  # Zod validation failed
-│   └── InvalidInputError      # Bad user input (template not found, etc.)
+│   ├── InvalidInputError      # Bad user input (template not found, etc.)
+│   └── DeploymentFailedError  # Deploy completed with failed resources
 │
 └── SystemError (something broke - needs investigation)
     ├── ApiError               # HTTP/network failures
@@ -109,6 +110,7 @@ See [api-patterns.md](api-patterns.md) for the full `ApiError.fromHttpError()` p
 | `CONFIG_EXISTS` | `ConfigExistsError` | Project already exists at location |
 | `SCHEMA_INVALID` | `SchemaValidationError` | Zod validation failed |
 | `INVALID_INPUT` | `InvalidInputError` | User provided invalid input |
+| `DEPLOYMENT_FAILED` | `DeploymentFailedError` | Deploy completed with failed resources |
 | `API_ERROR` | `ApiError` | API request failed |
 | `FILE_NOT_FOUND` | `FileNotFoundError` | File doesn't exist |
 | `FILE_READ_ERROR` | `FileReadError` | Can't read/write file |
diff --git a/packages/cli/src/cli/commands/functions/deploy.ts b/packages/cli/src/cli/commands/functions/deploy.ts
index b6beb023..c279dca5 100644
--- a/packages/cli/src/cli/commands/functions/deploy.ts
+++ b/packages/cli/src/cli/commands/functions/deploy.ts
@@ -1,5 +1,6 @@
 import type { Logger } from "@base44-cli/logger";
 import type { Command } from "commander";
+import { throwIfFunctionDeployFailed } from "@/cli/commands/functions/deployFailures.js";
 import { formatDeployResult } from "@/cli/commands/functions/formatDeployResult.js";
 import { parseNames } from "@/cli/commands/functions/parseNames.js";
 import type { CLIContext, RunCommandResult } from "@/cli/types.js";
@@ -100,6 +101,12 @@ async function deployFunctionsAction(
     },
   });
 
+  const summary = buildDeploySummary(results);
+  if (results.some((result) => result.status === "error")) {
+    log.info(summary);
+  }
+  throwIfFunctionDeployFailed(results);
+
   if (options.force) {
     const allLocalNames = functions.map((f) => f.name);
     let pruneCompleted = 0;
@@ -126,7 +133,7 @@ async function deployFunctionsAction(
     formatPruneSummary(pruneResults, log);
   }
 
-  return { outroMessage: buildDeploySummary(results) };
+  return { outroMessage: summary };
 }
 
 export function getDeployCommand(): Command {
diff --git a/packages/cli/src/cli/commands/functions/deployFailures.ts b/packages/cli/src/cli/commands/functions/deployFailures.ts
new file mode 100644
index 00000000..aebb9e37
--- /dev/null
+++ b/packages/cli/src/cli/commands/functions/deployFailures.ts
@@ -0,0 +1,20 @@
+import { DeploymentFailedError } from "@/core/errors.js";
+import type { SingleFunctionDeployResult } from "@/core/resources/function/deploy.js";
+
+function buildFunctionDeployFailureMessage(
+  results: SingleFunctionDeployResult[],
+): string | null {
+  const failed = results.filter((result) => result.status === "error").length;
+  if (failed === 0) return null;
+
+  return `${failed} ${failed === 1 ? "function" : "functions"} failed to deploy`;
+}
+
+export function throwIfFunctionDeployFailed(
+  results: SingleFunctionDeployResult[],
+): void {
+  const message = buildFunctionDeployFailureMessage(results);
+  if (message) {
+    throw new DeploymentFailedError(message);
+  }
+}
diff --git a/packages/cli/src/cli/commands/project/deploy.ts b/packages/cli/src/cli/commands/project/deploy.ts
index ad07fa79..2664743d 100644
--- a/packages/cli/src/cli/commands/project/deploy.ts
+++ b/packages/cli/src/cli/commands/project/deploy.ts
@@ -5,6 +5,7 @@ import {
   filterPendingOAuth,
   promptOAuthFlows,
 } from "@/cli/commands/connectors/oauth-prompt.js";
+import { throwIfFunctionDeployFailed } from "@/cli/commands/functions/deployFailures.js";
 import { formatDeployResult } from "@/cli/commands/functions/formatDeployResult.js";
 import type { CLIContext, RunCommandResult } from "@/cli/types.js";
 import {
@@ -130,6 +131,8 @@ export async function deployAction(
     );
   }
 
+  throwIfFunctionDeployFailed(result.functionResults);
+
   return { outroMessage: "App deployed successfully" };
 }
 
diff --git a/packages/cli/src/core/errors.ts b/packages/cli/src/core/errors.ts
index 5a358842..e3d8466a 100644
--- a/packages/cli/src/core/errors.ts
+++ b/packages/cli/src/core/errors.ts
@@ -262,6 +262,23 @@ export class InvalidInputError extends UserError {
   readonly code = "INVALID_INPUT";
 }
 
+/**
+ * Thrown when deployment completes with one or more failed resources.
+ */
+export class DeploymentFailedError extends UserError {
+  readonly code = "DEPLOYMENT_FAILED";
+
+  constructor(message: string, options?: CLIErrorOptions) {
+    super(message, {
+      hints: options?.hints ?? [
+        { message: "Check the deployment errors above and try again" },
+      ],
+      details: options?.details,
+      cause: options?.cause,
+    });
+  }
+}
+
 /**
  * Thrown when a required external dependency is not installed (e.g., Deno, Git).
  */
diff --git a/packages/cli/src/core/project/deploy.ts b/packages/cli/src/core/project/deploy.ts
index 68089173..d8fcff1d 100644
--- a/packages/cli/src/core/project/deploy.ts
+++ b/packages/cli/src/core/project/deploy.ts
@@ -43,6 +43,10 @@ export function hasResourcesToDeploy(projectData: ProjectData): boolean {
  * Result of deploying all project resources.
  */
 interface DeployAllResult {
+  /**
+   * Per-function deployment results, including any failed functions.
+   */
+  functionResults: SingleFunctionDeployResult[];
   /**
    * The app URL if a site was deployed, undefined otherwise.
    */
@@ -73,7 +77,7 @@ export async function deployAll(
     projectData;
 
   await entityResource.push(entities);
-  await deployFunctionsSequentially(functions, {
+  const functionResults = await deployFunctionsSequentially(functions, {
     onStart: options?.onFunctionStart,
     onResult: options?.onFunctionResult,
   });
@@ -84,8 +88,8 @@ export async function deployAll(
   if (project.site?.outputDirectory) {
     const outputDir = resolve(project.root, project.site.outputDirectory);
     const { appUrl } = await deploySite(outputDir);
-    return { appUrl, connectorResults };
+    return { functionResults, appUrl, connectorResults };
   }
 
-  return { connectorResults };
+  return { functionResults, connectorResults };
 }
diff --git a/packages/cli/tests/cli/deploy.spec.ts b/packages/cli/tests/cli/deploy.spec.ts
index bd59390d..7a43dc12 100644
--- a/packages/cli/tests/cli/deploy.spec.ts
+++ b/packages/cli/tests/cli/deploy.spec.ts
@@ -82,6 +82,25 @@ describe("deploy command (unified)", () => {
     t.expectResult(result).toContain("App deployed successfully");
   });
 
+  it("fails when a function deployment fails", async () => {
+    await t.givenLoggedInWithProject(fixture("with-functions-and-entities"));
+    t.api.mockEntitiesPush({ created: ["Order"], updated: [], deleted: [] });
+    t.api.mockSingleFunctionDeployError({
+      status: 400,
+      body: { error: "Invalid function code" },
+    });
+    t.api.mockAgentsPush({ created: [], updated: [], deleted: [] });
+    t.api.mockConnectorsList({ integrations: [] });
+    t.api.mockStripeStatus({ stripe_mode: null });
+
+    const result = await t.run("deploy", "-y");
+
+    t.expectResult(result).toFail();
+    t.expectResult(result).toContain("Invalid function code");
+    t.expectResult(result).toContain("1 function failed to deploy");
+    t.expectResult(result).toNotContain("App deployed successfully");
+  });
+
   it("deploys zero-config functions (path-based names) with unified deploy", async () => {
     await t.givenLoggedInWithProject(fixture("with-zero-config-functions"));
     t.api.mockEntitiesPush({ created: [], updated: [], deleted: [] });
diff --git a/packages/cli/tests/cli/functions_deploy.spec.ts b/packages/cli/tests/cli/functions_deploy.spec.ts
index 44af56b2..79b06c56 100644
--- a/packages/cli/tests/cli/functions_deploy.spec.ts
+++ b/packages/cli/tests/cli/functions_deploy.spec.ts
@@ -98,9 +98,10 @@ describe("functions deploy command", () => {
 
     const result = await t.run("functions", "deploy");
 
-    t.expectResult(result).toSucceed();
+    t.expectResult(result).toFail();
     t.expectResult(result).toContain("error");
     t.expectResult(result).toContain("1 error");
+    t.expectResult(result).toContain("1 function failed to deploy");
   });
 
   it("reports validation error from 422 response", async () => {
@@ -114,11 +115,12 @@ describe("functions deploy command", () => {
 
     const result = await t.run("functions", "deploy");
 
-    t.expectResult(result).toSucceed();
+    t.expectResult(result).toFail();
     t.expectResult(result).toContain("error");
     t.expectResult(result).toContain(
       "Minimum interval for minute-based schedules is 5 minutes.",
     );
+    t.expectResult(result).toContain("1 function failed to deploy");
   });
 
   it("reports too-many-functions error from 422 response", async () => {
@@ -132,11 +134,64 @@ describe("functions deploy command", () => {
 
     const result = await t.run("functions", "deploy");
 
-    t.expectResult(result).toSucceed();
+    t.expectResult(result).toFail();
     t.expectResult(result).toContain("error");
     t.expectResult(result).toContain(
       "Maximum of 50 functions per app reached.",
     );
+    t.expectResult(result).toContain("1 function failed to deploy");
+  });
+
+  it("prunes remote functions missing locally with --force", async () => {
+    await t.givenLoggedInWithProject(fixture("with-functions-and-entities"));
+    t.api.mockSingleFunctionDeploy({ status: "deployed" });
+    t.api.mockFunctionsList({
+      functions: [
+        {
+          name: "stale-function",
+          deployment_id: "dep_123",
+          entry: "index.ts",
+          files: [],
+          automations: [],
+        },
+      ],
+    });
+    t.api.mockSingleFunctionDelete();
+
+    const result = await t.run("functions", "deploy", "--force");
+
+    t.expectResult(result).toSucceed();
+    t.expectResult(result).toContain("Found 1 remote function to delete");
+    t.expectResult(result).toContain("stale-function");
+    t.expectResult(result).toContain("deleted");
+    t.expectResult(result).toContain("1 deleted");
+  });
+
+  it("does not prune remote functions when deploy fails with --force", async () => {
+    await t.givenLoggedInWithProject(fixture("with-functions-and-entities"));
+    t.api.mockSingleFunctionDeployError({
+      status: 400,
+      body: { error: "Invalid function code" },
+    });
+    t.api.mockFunctionsList({
+      functions: [
+        {
+          name: "stale-function",
+          deployment_id: "dep_123",
+          entry: "index.ts",
+          files: [],
+          automations: [],
+        },
+      ],
+    });
+    t.api.mockSingleFunctionDelete();
+
+    const result = await t.run("functions", "deploy", "--force");
+
+    t.expectResult(result).toFail();
+    t.expectResult(result).toContain("1 function failed to deploy");
+    t.expectResult(result).toNotContain("Found 1 remote function to delete");
+    t.expectResult(result).toNotContain("stale-function");
   });
 
   it("rejects --force with specific function names", async () => {