chenhg5/cc-connect · error

wecom: upload image: empty media_id

Error message

wecom: upload image: empty media_id

What it means

Inconsistency guard after a successful image upload: WeCom returned errcode 0 but an empty media_id, leaving nothing to reference in the subsequent message/send. The API contract promises a media_id on success, so this indicates a malformed success response or an API-side change.

Source

Thrown at platform/wecom/wecom.go:585

	resp, err := p.apiClient.Post(apiURL, writer.FormDataContentType(), body)
	if err != nil {
		return "", fmt.Errorf("wecom: upload image: %w", err)
	}
	defer resp.Body.Close()

	var result struct {
		ErrCode int    `json:"errcode"`
		ErrMsg  string `json:"errmsg"`
		MediaID string `json:"media_id"`
	}
	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
		return "", fmt.Errorf("wecom: decode upload response: %w", err)
	}
	if result.ErrCode != 0 {
		return "", fmt.Errorf("wecom: upload image failed: %d %s", result.ErrCode, result.ErrMsg)
	}
	if result.MediaID == "" {
		return "", fmt.Errorf("wecom: upload image: empty media_id")
	}
	return result.MediaID, nil
}

var _ core.ImageSender = (*Platform)(nil)

func (p *Platform) sendMarkdown(accessToken, toUser, content string) error {
	payload := map[string]any{
		"touser":   toUser,
		"msgtype":  "markdown",
		"agentid":  p.agentID,
		"markdown": map[string]string{"content": content},
	}

	body, _ := json.Marshal(payload)
	apiURL := p.wecomAPIURL("/cgi-bin/message/send", url.Values{
		"access_token": []string{accessToken},
	})

View on GitHub (pinned to 4000b2338a)

Solutions

1. Retry the upload once — transient malformed responses do occur
2. If persistent, capture the full response body and check WeCom API docs for contract changes
3. Fail the image send gracefully with a text fallback message instead of leaking the internal error

When it happens

Trigger: Thrown at platform/wecom/wecom.go:585 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/008aef8429376eb1. Report an issue: GitHub.