chenhg5/cc-connect · error

googlechat: invalid reply context type %T

Error message

googlechat: invalid reply context type %T

What it means

SendPreviewStart (core.PreviewStarter) type-asserts its reply-context argument to googlechat.replyContext. Any other value — including contexts from other platforms — fails and yields this error, which reports the actual dynamic type via %T.

Source

Thrown at platform/googlechat/streaming.go:28

	"net/http"

	"github.com/chenhg5/cc-connect/core"
)

// previewHandle points at the in-flight streaming-preview message so
// UpdateMessage can patch it in place via spaces.messages.patch.
type previewHandle struct {
	name string // e.g. "spaces/AAA/messages/MMM"
}

// SendPreviewStart posts the initial streaming-preview message (threaded like a
// normal reply) and returns a handle for subsequent edits. Implements
// core.PreviewStarter; together with UpdateMessage it lights up the engine's
// real-time streaming preview for Google Chat.
func (p *Platform) SendPreviewStart(ctx context.Context, rctx any, content string) (any, error) {
	rc, ok := rctx.(replyContext)
	if !ok {
		return nil, fmt.Errorf("googlechat: invalid reply context type %T", rctx)
	}
	if rc.space == "" {
		return nil, fmt.Errorf("googlechat: missing space in reply context")
	}
	url, body, err := buildSendRequest(rc, content)
	if err != nil {
		return nil, err
	}
	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(body))
	if err != nil {
		return nil, fmt.Errorf("googlechat: build request: %w", err)
	}
	req.Header.Set("Content-Type", "application/json")
	resp, err := p.doRequest(req)
	if err != nil {
		return nil, fmt.Errorf("googlechat: send preview: %w", err)
	}
	defer func() {

View on GitHub (pinned to 4000b2338a)

Solutions

1. Ensure streaming preview is only enabled for messages routed by the googlechat platform
2. Verify the platform wiring passes its own replyContext to SendPreviewStart
3. Add a capability check before enabling the preview feature for the platform

Example fix

// before
handle, err := gc.SendPreviewStart(ctx, otherCtx, content)
// after
if _, ok := otherCtx.(googlechat.ReplyContext); !ok {
    return fmt.Errorf("preview not supported for this reply context")
}
handle, err := gc.SendPreviewStart(ctx, otherCtx, content)

func supportsPreview(rctx any) bool { _, ok := rctx.(replyContext); return ok }

handle, err := p.SendPreviewStart(ctx, rctx, content)
if err != nil && strings.Contains(err.Error(), "invalid reply context type") {
    return fallbackToPlainReply(ctx, rctx, content)
}

When it happens

Trigger: Streaming preview enabled for a googlechat agent but the engine hands SendPreviewStart a foreign/nil reply context; mixing platform adapters.

Common situations: Multi-platform deployments where the preview pipeline shares one context type; misconfigured platform routing sending a telegram/slack context to googlechat.

Understand the failure class

Background: Type mismatch errors: IllegalArgumentException, TypeError and type guards across 150 open-source libraries — this error's family across 150 libraries.

Related errors

• googlechat: SendImage: invalid reply context type %T
• googlechat: SendFile: invalid reply context type %T
• googlechat: missing space in reply context
• googlechat: build request: %w
• googlechat: send preview: %w

AI-assisted analysis of chenhg5/cc-connect@4000b2338a (2026-09-06). Data as JSON: /api/errors/2e5c369599bc3349. Report an issue: GitHub.