Description

Sending images or files via QQ Bot C2C (private chat) fails with HTTP 400 Bad Request. Text-only messages work fine (200 OK).

Steps to Reproduce

1. Configure QQ Bot with appId and clientSecret
2. Send a message with media, buffer, or attachments parameter via the message tool
3. Check gateway logs

Expected Behavior

Image/file should be delivered to the QQ C2C chat.

Actual Behavior

• The message tool returns success (no error thrown)
• But platformMessageIds is empty in the receipt
• Gateway logs show: [qqbot:api] <<< Status: 400 Bad Request
• Multiple attempts tried: media param, buffer (base64), attachments — all return 400
• Pure text messages work normally (200 OK)

Log Evidence

[default] [qqbot:api] <<< Status: 400 Bad Request | TraceId: 6db8273c2c4e3eb936e2e4eb8218cd48
[default] [qqbot:api] <<< Status: 400 Bad Request | TraceId: 563af3169be2104176625935f0c23223
[default] [qqbot:api] <<< Status: 400 Bad Request | TraceId: d8795ef3689d1027a165507e96ddcd73

Environment

• OpenClaw version: 2026.6.5
• QQ Bot plugin: @openclaw/qqbot
• Channel: C2C (private chat)
• OS: Ubuntu x86_64
• Node: v24.16.0

Suspected Cause

QQ Bot C2C API may require a specific media upload flow (upload → get file_info → reference in message) that is not being used when sending via the generic message tool.

Additional Notes

• qqbot_channel_api tool only covers guild/channel endpoints, not C2C media upload
• Group chat media sending not tested (only C2C)
• The urlDirectUpload config option was tested but did not help