claude-code

src/bridge/inboundMessages.ts

@@ -0,0 +1,82 @@
+import type {
+  Base64ImageSource,
+  ContentBlockParam,
+  ImageBlockParam,
+} from '@anthropic-ai/sdk/resources/messages.mjs'
+import type { UUID } from 'crypto'
+import type { SDKMessage } from '../entrypoints/agentSdkTypes.js'
+import { detectImageFormatFromBase64 } from '../utils/imageResizer.js'
+
+/**
+ * Process an inbound user message from the bridge, extracting content
+ * and UUID for enqueueing. Supports both string content and
+ * ContentBlockParam[] (e.g. messages containing images).
+ *
+ * Normalizes image blocks from bridge clients that may use camelCase
+ * `mediaType` instead of snake_case `media_type` (mobile-apps#5825).
+ *
+ * Returns the extracted fields, or undefined if the message should be
+ * skipped (non-user type, missing/empty content).
+ */
+export function extractInboundMessageFields(
+  msg: SDKMessage,
+):
+  | { content: string | Array<ContentBlockParam>; uuid: UUID | undefined }
+  | undefined {
+  if (msg.type !== 'user') return undefined
+  const content = msg.message?.content
+  if (!content) return undefined
+  if (Array.isArray(content) && content.length === 0) return undefined
+
+  const uuid =
+    'uuid' in msg && typeof msg.uuid === 'string'
+      ? (msg.uuid as UUID)
+      : undefined
+
+  return {
+    content: Array.isArray(content) ? normalizeImageBlocks(content) : content,
+    uuid,
+  }
+}
+
+/**
+ * Normalize image content blocks from bridge clients. iOS/web clients may
+ * send `mediaType` (camelCase) instead of `media_type` (snake_case), or
+ * omit the field entirely. Without normalization, the bad block poisons
+ * the session — every subsequent API call fails with
+ * "media_type: Field required".
+ *
+ * Fast-path scan returns the original array reference when no
+ * normalization is needed (zero allocation on the happy path).
+ */
+export function normalizeImageBlocks(
+  blocks: Array<ContentBlockParam>,
+): Array<ContentBlockParam> {
+  if (!blocks.some(isMalformedBase64Image)) return blocks
+
+  return blocks.map(block => {
+    if (!isMalformedBase64Image(block)) return block
+    const src = block.source as unknown as Record<string, unknown>
+    const mediaType =
+      typeof src.mediaType === 'string' && src.mediaType
+        ? src.mediaType
+        : detectImageFormatFromBase64(block.source.data)
+    return {
+      ...block,
+      source: {
+        type: 'base64' as const,
+        media_type: mediaType as Base64ImageSource['media_type'],
+        data: block.source.data,
+      },
+    }
+  })
+}
+
+function isMalformedBase64Image(
+  block: ContentBlockParam,
+): block is ImageBlockParam & { source: Base64ImageSource } {
+  if (block.type !== 'image' || block.source?.type !== 'base64') return false
+  return !(block.source as unknown as Record<string, unknown>).media_type
+}
+
+