diff --git a/CHANGELOG.md b/CHANGELOG.md
index 228d580b7..aadfe9650 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -76,6 +76,7 @@
 - macOS: log health refresh failures and recovery to make gateway issues easier to diagnose.
 - macOS codesign: skip hardened runtime for ad-hoc signing and avoid empty options args (#70) — thanks @petter-b
 - macOS codesign: include camera entitlement so permission prompts work in the menu bar app.
+- Agent tools: map `camera.snap` JPEG payloads to `image/jpeg` to avoid MIME mismatch errors.
 - macOS packaging: move rpath config into swift build for reliability (#69) — thanks @petter-b
 - macOS: prioritize main bundle for device resources to prevent crash (#73) — thanks @petter-b
 - macOS remote: route settings through gateway config and avoid local config reads in remote mode.
diff --git a/src/agents/clawdis-tools.ts b/src/agents/clawdis-tools.ts
index 2b3a37647..65b776b0e 100644
--- a/src/agents/clawdis-tools.ts
+++ b/src/agents/clawdis-tools.ts
@@ -43,7 +43,7 @@ import { parseDurationMs } from "../cli/parse-duration.js";
 import { loadConfig } from "../config/config.js";
 import { reactMessageDiscord } from "../discord/send.js";
 import { callGateway } from "../gateway/call.js";
-import { detectMime } from "../media/mime.js";
+import { detectMime, imageMimeFromFormat } from "../media/mime.js";
 import { sanitizeToolResultImages } from "./tool-images.js";
 
 // biome-ignore lint/suspicious/noExplicitAny: TypeBox schema type from pi-ai uses a different module instance.
@@ -875,7 +875,7 @@ function createCanvasTool(): AnyAgentTool {
           });
           await writeBase64ToFile(filePath, payload.base64);
           const mimeType =
-            payload.format === "jpeg" ? "image/jpeg" : "image/png";
+            imageMimeFromFormat(payload.format) ?? "image/png";
           return await imageResult({
             label: "canvas:snapshot",
             path: filePath,
@@ -1141,7 +1141,8 @@ function createNodesTool(): AnyAgentTool {
             content.push({
               type: "image",
               data: payload.base64,
-              mimeType: payload.format === "jpeg" ? "image/jpeg" : "image/png",
+              mimeType:
+                imageMimeFromFormat(payload.format) ?? "image/png",
             });
             details.push({
               facing,
diff --git a/src/media/mime.test.ts b/src/media/mime.test.ts
index 3eeb72a68..425a36a6b 100644
--- a/src/media/mime.test.ts
+++ b/src/media/mime.test.ts
@@ -1,7 +1,7 @@
 import JSZip from "jszip";
 import { describe, expect, it } from "vitest";
 
-import { detectMime } from "./mime.js";
+import { detectMime, imageMimeFromFormat } from "./mime.js";
 
 async function makeOoxmlZip(opts: {
   mainMime: string;
@@ -17,6 +17,15 @@ async function makeOoxmlZip(opts: {
 }
 
 describe("mime detection", () => {
+  it("maps common image formats to mime types", () => {
+    expect(imageMimeFromFormat("jpg")).toBe("image/jpeg");
+    expect(imageMimeFromFormat("jpeg")).toBe("image/jpeg");
+    expect(imageMimeFromFormat("png")).toBe("image/png");
+    expect(imageMimeFromFormat("webp")).toBe("image/webp");
+    expect(imageMimeFromFormat("gif")).toBe("image/gif");
+    expect(imageMimeFromFormat("unknown")).toBeUndefined();
+  });
+
   it("detects docx from buffer", async () => {
     const buf = await makeOoxmlZip({
       mainMime:
diff --git a/src/media/mime.ts b/src/media/mime.ts
index 0f6bf057c..d26cfb969 100644
--- a/src/media/mime.ts
+++ b/src/media/mime.ts
@@ -107,6 +107,25 @@ export function extensionForMime(mime?: string | null): string | undefined {
   return EXT_BY_MIME[mime.toLowerCase()];
 }
 
+export function imageMimeFromFormat(
+  format?: string | null,
+): string | undefined {
+  if (!format) return undefined;
+  switch (format.toLowerCase()) {
+    case "jpg":
+    case "jpeg":
+      return "image/jpeg";
+    case "png":
+      return "image/png";
+    case "webp":
+      return "image/webp";
+    case "gif":
+      return "image/gif";
+    default:
+      return undefined;
+  }
+}
+
 export function kindFromMime(mime?: string | null): MediaKind {
   return mediaKindFromMime(mime);
 }