charmbracelet/crush · warning

failed to marshal oauth token: %w

Error message

failed to marshal oauth token: %w

What it means

SetProviderAPIKey marshals the *oauth.Token to JSON for the request body. This error wraps a json.Marshal failure on the token — typically caused by a field on the token that cannot be serialized (channels, funcs, or a custom MarshalJSON that errors).

Source

Thrown at internal/client/config.go:104

		kind proto.APIKeyKind
		raw  json.RawMessage
	)
	switch v := apiKey.(type) {
	case string:
		kind = proto.APIKeyKindString
		b, err := json.Marshal(v)
		if err != nil {
			return fmt.Errorf("failed to marshal api key string: %w", err)
		}
		raw = b
	case *oauth.Token:
		if v == nil {
			return fmt.Errorf("oauth token is nil")
		}
		kind = proto.APIKeyKindOAuth
		b, err := json.Marshal(v)
		if err != nil {
			return fmt.Errorf("failed to marshal oauth token: %w", err)
		}
		raw = b
	default:
		return fmt.Errorf("unsupported api key type %T", apiKey)
	}

	rsp, err := c.post(ctx, fmt.Sprintf("/workspaces/%s/config/provider-key", id), nil, jsonBody(proto.ConfigProviderKeyRequest{
		Scope:      scope,
		ProviderID: providerID,
		Kind:       kind,
		APIKey:     raw,
	}), http.Header{"Content-Type": []string{"application/json"}})
	if err != nil {
		return fmt.Errorf("failed to set provider API key: %w", err)
	}
	defer rsp.Body.Close()
	if rsp.StatusCode != http.StatusOK {
		return fmt.Errorf("failed to set provider API key: status code %d", rsp.StatusCode)

View on GitHub (pinned to 7944b8e522)

Solutions

1. Inspect the wrapped %w error to find the offending field
2. Ensure the token struct contains only JSON-serializable fields
3. Remove or fix any custom MarshalJSON implementation on the token type

if _, err := json.Marshal(tok); err != nil {
    return fmt.Errorf("oauth token not serializable: %w", err)
}

if err := c.SetProviderAPIKey(ctx, wsID, scope, pid, tok); err != nil {
    if strings.Contains(err.Error(), "marshal oauth token") {
        return fmt.Errorf("token contains unsupported fields: %w", err)
    }
    return err
}

When it happens

Trigger: Calling SetProviderAPIKey with an *oauth.Token whose MarshalJSON (or an unexported field with a custom marshaler) returns an error.

Common situations: A custom or third-party oauth.Token type with unsupported field types, or a corrupted/populated-with-functions token struct.

Related errors

• failed to marshal api key string: %w
• failed to decode MCP auth URL: %w
• marshal request: %w
• github copilot not available
• ${ErrorDescription}

AI-assisted analysis of charmbracelet/crush@7944b8e522 (2026-08-29). Data as JSON: /api/errors/aea2a7f1abbe46f8. Report an issue: GitHub.