chenhg5/cc-connect · error

slack: SendImage: invalid reply context type %T

Error message

slack: SendImage: invalid reply context type %T

What it means

Type-assertion guard in Slack SendImage: rctx is not the platform's internal replyContext struct, so the target channel/thread for the upload cannot be determined.

Source

Thrown at platform/slack/slack.go:498

	opts := []slack.MsgOption{
		slack.MsgOptionText(core.MarkdownToSlackMrkdwn(content), false),
	}
	if rc.timestamp != "" {
		opts = append(opts, slack.MsgOptionPostMessageParameters(slack.PostMessageParameters{ThreadTimestamp: rc.timestamp}))
	}
	_, _, err := p.client.PostMessageContext(ctx, rc.channel, opts...)
	if err != nil {
		return fmt.Errorf("slack: send: %w", err)
	}
	return nil
}

// SendImage uploads and sends an image to the channel.
// Implements core.ImageSender.
func (p *Platform) SendImage(ctx context.Context, rctx any, img core.ImageAttachment) error {
	rc, ok := rctx.(replyContext)
	if !ok {
		return fmt.Errorf("slack: SendImage: invalid reply context type %T", rctx)
	}

	name := img.FileName
	if name == "" {
		name = "image.png"
	}

	_, err := p.client.UploadFileV2Context(ctx, slack.UploadFileV2Parameters{
		Reader:          bytes.NewReader(img.Data),
		FileSize:        len(img.Data),
		Filename:        name,
		Channel:         rc.channel,
		ThreadTimestamp: rc.timestamp,
	})
	if err != nil {
		return fmt.Errorf("slack: send image: %w", err)
	}
	return nil

View on GitHub (pinned to 4000b2338a)

Solutions

1. Pass a Slack-produced reply context

When it happens

Trigger: Thrown at platform/slack/slack.go:498 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of chenhg5/cc-connect@4000b2338a (2026-09-06). Data as JSON: /api/errors/35ab7d8d337789e3. Report an issue: GitHub.