larksuite/cli · error

failed to parse response: %w

Error message

failed to parse response: %w

What it means

getAppInfo calls the Lark auth API (ApplicationInfoPath) and decodes the raw HTTP body into appInfoResponse. If json.Unmarshal fails because the body is not valid JSON or does not match the struct, the error is wrapped as "failed to parse response". This distinguishes a decode-level problem from a Lark business error (resp.Code != 0), which is classified separately by classifyAppInfoErr.

Source

Thrown at cmd/auth/auth.go:161

	if err != nil {
		return nil, err
	}

	queryParams := make(larkcore.QueryParams)
	queryParams.Set("lang", "zh_cn")

	apiResp, err := ac.DoSDKRequest(ctx, &larkcore.ApiReq{
		HttpMethod:  http.MethodGet,
		ApiPath:     larkauth.ApplicationInfoPath(appId),
		QueryParams: queryParams,
	}, core.AsBot)
	if err != nil {
		return nil, err
	}

	var resp appInfoResponse
	if err := json.Unmarshal(apiResp.RawBody, &resp); err != nil {
		return nil, fmt.Errorf("failed to parse response: %w", err)
	}
	if resp.Code != 0 {
		return nil, classifyAppInfoErr(apiResp.RawBody, resp.Code, resp.Msg, f, appId)
	}

	app := resp.Data.App
	ownerOpenId := app.Owner.OwnerID
	if ownerOpenId == "" {
		ownerOpenId = app.CreatorID
	}

	var userScopes []string
	for _, s := range app.Scopes {
		if s.Scope == "" || !slices.Contains(s.TokenTypes, "user") {
			continue
		}
		userScopes = append(userScopes, s.Scope)
	}

View on GitHub (pinned to 7fd6ef3c07)

Solutions

1. Inspect the raw body: re-run with verbose/debug logging (larkcore debug env) to see what was actually returned before the unmarshal failure.
2. Check network path: bypass proxies/VPNs or fix HTTPS_PROXY settings so requests reach open.feishu.cn directly.
3. Verify the app ID and endpoint: a wrong appId can hit a route returning a non-JSON error page; confirm with a manual curl of the same path.
4. Upgrade or pin the lark SDK (larkcore/larkauth) and lark-cli to matching versions so the response schema matches the decoder.

Example fix

// before: opaque wrap hides body contents
return nil, fmt.Errorf("failed to parse response: %w", err)
// after: include a body snippet to diagnose proxies/HTML responses
snippet := apiResp.RawBody
if len(snippet) > 200 {
	snippet = snippet[:200]
}
return nil, fmt.Errorf("failed to parse response: %w (body: %q)", err, snippet)

// Pre-flight: confirm the API path returns JSON before decoding
resp, err := http.Get("https://open.feishu.cn/open-apis/auth/v3/app_info?app_id=" + appId)
if err != nil { return err }
ct := resp.Header.Get("Content-Type")
if !strings.Contains(ct, "application/json") {
	return fmt.Errorf("expected JSON, got %s (status %d)", ct, resp.StatusCode)
}

func isJSONDecodeErr(err error) bool {
	var syn *json.SyntaxError
	var typ *json.UnmarshalTypeError
	return errors.As(err, &syn) || errors.As(err, &typ)
}

info, err := getAppInfo(ctx, f, appId)
if err != nil {
	if isJSONDecodeErr(err) {
		// non-JSON body: retry via a different network path or surface a proxy hint
		log.Printf("API returned non-JSON body: %v", err)
		return retryViaDirectConnection(ctx, appId)
	}
	return err
}

When it happens

Trigger: Any lark-cli auth command that resolves app info (e.g. app-credential/scopes flows calling getAppInfo) when the API returns a response whose RawBody cannot be unmarshaled: an HTML login/error page, a proxy or captive-portal response, a truncated/garbled body, or an unexpected schema shape after SDK version changes.

Common situations: Corporate proxy or VPN intercepting open.feishu.cn and returning HTML; pointing the CLI at a wrong base URL or mock endpoint; an SDK/larkcore upgrade that changed the response envelope so the struct no longer matches; network middleware returning gzip/binary content.

Understand the failure class

Background: "failed to unmarshal" / json.Unmarshal errors: why parsing a response into a Go struct fails and how to fix it — this error's family across 23 libraries.

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• response parse error: %w (body: %s)
• failed to parse user info: %w
• parse range start: %w
• parse range end: %w
• parse total size: %w

AI-assisted analysis of larksuite/cli@7fd6ef3c07 (2026-09-04). Data as JSON: /api/errors/d583a97cc98a3790. Report an issue: GitHub.