feat(bot): add image attachment support for Slack bot#2749
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When users attach images to their Slack messages, the bot now extracts them via the chat SDK's fetchData() method (which handles Slack auth), uploads them to R2 in the Cloud Agent attachments bucket, and forwards the image references to the Cloud Agent session via PrepareSessionInput. This bridges Slack's file attachment format to the existing Cloud Agent image pipeline without requiring any changes to the Cloud Agent worker.
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Code Review SummaryStatus: No Issues Found | Recommendation: Merge Files Reviewed (4 files)
Reviewed by gpt-5.5-2026-04-23 · 432,169 tokens |
eshurakov
reviewed
Apr 28, 2026
Comment on lines
+48
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+94
| const toProcess = imageAttachments.slice(0, CLOUD_AGENT_IMAGE_MAX_COUNT); | ||
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| const messageUuid = randomUUID(); | ||
| const filenames: string[] = []; | ||
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| for (const attachment of toProcess) { | ||
| try { | ||
| const imageId = randomUUID(); | ||
| const ext = CLOUD_AGENT_IMAGE_MIME_TO_EXTENSION[attachment.mimeType]; | ||
| const filename = `${imageId}.${ext}`; | ||
| const r2Key = `${userId}/cloud-agent/${messageUuid}/${filename}`; | ||
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| if ( | ||
| typeof attachment.size === 'number' && | ||
| attachment.size > CLOUD_AGENT_IMAGE_MAX_SIZE_BYTES | ||
| ) { | ||
| throw new Error( | ||
| `Image ${attachment.name ?? filename} exceeds ${CLOUD_AGENT_IMAGE_MAX_SIZE_BYTES / (1024 * 1024)}MB limit (${(attachment.size / (1024 * 1024)).toFixed(1)}MB)` | ||
| ); | ||
| } | ||
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| const data = await attachment.fetchData(); | ||
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| if (data.byteLength > CLOUD_AGENT_IMAGE_MAX_SIZE_BYTES) { | ||
| throw new Error( | ||
| `Image ${attachment.name ?? filename} exceeds ${CLOUD_AGENT_IMAGE_MAX_SIZE_BYTES / (1024 * 1024)}MB limit (${(data.byteLength / (1024 * 1024)).toFixed(1)}MB)` | ||
| ); | ||
| } | ||
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| await r2Client.send( | ||
| new PutObjectCommand({ | ||
| Bucket: r2CloudAgentAttachmentsBucketName, | ||
| Key: r2Key, | ||
| Body: data, | ||
| ContentType: attachment.mimeType, | ||
| ContentLength: data.byteLength, | ||
| Metadata: { userId, messageUuid, imageId }, | ||
| }) | ||
| ); | ||
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| filenames.push(filename); | ||
| } catch (error) { | ||
| console.error('[KiloBot] Failed to upload image attachment:', error); | ||
| captureException(error, { | ||
| tags: { component: 'kilo-bot', op: 'upload-slack-image' }, | ||
| }); | ||
| } |
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This piece is probably very similar to what cloud agent is doing and can be extracted into a common method
eshurakov
approved these changes
Apr 28, 2026
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Summary
fetchData(), uploaded to R2 in the Cloud Agent attachments bucket, and forwarded to the Cloud Agent session viaPrepareSessionInput.images.Visual Changes
Reviewer Notes
extractAndUploadImagesutility (apps/web/src/lib/bot/images.ts) uses the chat SDK'sAttachment.fetchData()which handles Slack'surl_privateauthentication automatically via the bot token — no manual token handling needed.PutObjectCommand(unlike the browser flow which uses presigned URLs). This is analogous to howcli-sessions.tsdoes direct R2 uploads.{userId}/cloud-agent/{messageUuid}/{imageId}.{ext}.imagesfield inprepareSession.Built for Mark IJbema by Kilo for Slack