router-for-me/CLIProxyAPI · error

marshal request body: %w

Error message

marshal request body: %w

What it means

Returned by AntigravityAuth.FetchProjectID when encoding the loadCodeAssist request body to JSON fails. The payload is a statically built map ({"metadata": {"ideType": "ANTIGRAVITY"}}) containing only string keys and string values, so json.Marshal cannot fail for any realistic input. The error exists only as a defensive guard against programming mistakes (e.g. someone later adding an unmarshalable type such as a channel or func to the map). If you see it, code was modified to put an unsupported type into loadReqBody.

Source

Thrown at internal/auth/antigravity/auth.go:235

		return "", fmt.Errorf("antigravity userinfo: decode response: %w", errDecode)
	}
	email := strings.TrimSpace(info.Email)
	if email == "" {
		return "", fmt.Errorf("antigravity userinfo: response missing email")
	}
	return email, nil
}

// FetchProjectID retrieves the project ID for the authenticated user via loadCodeAssist
func (o *AntigravityAuth) FetchProjectID(ctx context.Context, accessToken string) (string, error) {
	userAgent := o.shortUserAgent()
	loadReqBody := map[string]any{
		"metadata": antigravityLoadCodeAssistMetadata(),
	}

	rawBody, errMarshal := json.Marshal(loadReqBody)
	if errMarshal != nil {
		return "", fmt.Errorf("marshal request body: %w", errMarshal)
	}

	endpointURL := fmt.Sprintf("%s/%s:loadCodeAssist", APIEndpoint, APIVersion)
	req, err := http.NewRequestWithContext(ctx, http.MethodPost, endpointURL, strings.NewReader(string(rawBody)))
	if err != nil {
		return "", fmt.Errorf("create request: %w", err)
	}
	req.Header.Set("Authorization", "Bearer "+accessToken)
	req.Header.Set("Accept", "*/*")
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("User-Agent", userAgent)

	resp, errDo := o.httpClient.Do(req)
	if errDo != nil {
		return "", fmt.Errorf("execute request: %w", errDo)
	}
	defer func() {
		if errClose := resp.Body.Close(); errClose != nil {

View on GitHub (pinned to 78f0c4079e)

Solutions

1. Inspect antigravityLoadCodeAssistMetadata() and any local additions to loadReqBody for values of type chan, func, complex, or self-referencing structs
2. Replace unmarshalable values with their string or plain-struct equivalents
3. Run go test ./internal/auth/antigravity/ to confirm the round trip

if _, err := auth.FetchProjectID(ctx, token); err != nil {
    var target *json.MarshalerError // not directly reachable; treat as programming bug
    if errors.As(err, &target) {
        log.Errorf("request payload bug: %v", err)
    }
}

When it happens

Trigger: Calling FetchProjectID after the request-body map was changed to contain a value json.Marshal cannot encode (chan, func, complex, cyclic pointer). With the shipped literal map this branch is effectively unreachable.

Common situations: Developers extending antigravityLoadCodeAssistMetadata() with non-string fields (timestamps as time.Time are fine, but func values or cyclic structs are not); essentially never seen in production.

Related errors

• antigravity token exchange: decode response: %w
• antigravity userinfo: decode response: %w
• antigravity token exchange: create request: %w
• antigravity token exchange: execute request: %w
• antigravity token exchange: read response: %w

AI-assisted analysis of router-for-me/CLIProxyAPI@78f0c4079e (2026-08-15). Data as JSON: /api/errors/9616d47a2192d4a0. Report an issue: GitHub.