Checkstack Documentation

Sending Configuration Schemas to Frontend

This guide documents the required pattern for exposing plugin configuration schemas to the frontend to enable dynamic form rendering with proper secret field handling.

Overview

When building admin UIs for plugins, configuration schemas must be converted to JSON Schema format and sent to the frontend. The critical requirement is to use the custom toJsonSchema() utility from @checkstack/backend-api instead of Zod’s native toJSONSchema() method.

The Problem

The DynamicForm component in @checkstack/ui automatically renders password input fields (with show/hide toggles) for fields marked as secrets. However, it relies on the x-secret metadata in the JSON Schema to identify these fields.

Zod’s native method does NOT add this metadata:

// ❌ WRONG: Missing x-secret metadata
import { z } from "zod";
const jsonSchema = mySchema.toJSONSchema();
// Result: Secret fields render as regular text inputs

The Solution

Use the custom toJsonSchema() function from @checkstack/backend-api:

// ✅ CORRECT: Adds x-secret metadata
import { toJsonSchema } from "@checkstack/backend-api";
const jsonSchema = toJsonSchema(mySchema);
// Result: Secret fields render as password inputs with show/hide toggle

Complete Implementation Pattern

1. Backend Router

When exposing plugin/strategy metadata to the frontend:

import { implement } from "@orpc/server";
import { autoAuthMiddleware, type RpcContext, toJsonSchema } from "@checkstack/backend-api";
import { myPluginContract } from "@checkstack/myplugin-common";

// Contract-based implementation with auto auth enforcement
const os = implement(myPluginContract)
  .$context<RpcContext>()
  .use(autoAuthMiddleware);

export const createMyPluginRouter = () => {
  return os.router({
    // Auth and access rules auto-enforced from contract meta
    getPlugins: os.getPlugins.handler(async ({ context }) => {
      const plugins = context.myPluginRegistry.getPlugins().map((p) => ({
        id: p.id,
        displayName: p.displayName,
        description: p.description,
        configVersion: p.configVersion,
        configSchema: toJsonSchema(p.configSchema),  // ✅ Use custom function
      }));
      return plugins;
    }),
  });
};

2. Plugin/Strategy Schema Definition

Use factory functions for fields that need specialized handling:

import { configString, configNumber, configBoolean } from "@checkstack/backend-api";
import { z } from "zod";

const configSchema = z.object({
  host: configString({}).default("localhost").describe("API host"),
  port: configNumber({}).default(443).describe("API port"),
  apiKey: configString({ "x-secret": true }).describe("API authentication key"),  // Marked as secret
  username: configString({}).optional().describe("Username"),
  password: configString({ "x-secret": true }).optional().describe("Password"),   // Marked as secret
});

3. Frontend Consumption

The frontend automatically handles the password fields:

import { PluginConfigForm } from "@checkstack/ui";

// The configSchema from the backend already has x-secret metadata
<PluginConfigForm
  plugins={plugins}  // Contains schemas with x-secret metadata
  selectedPluginId={selectedPluginId}
  config={config}
  onConfigChange={setConfig}
/>

How It Works

Backend: Schema Conversion Process

The toJsonSchema() function in schema-utils.ts:

1. Calls Zod’s native toJSONSchema() to get the base JSON Schema
2. Traverses the Zod schema to identify fields created with branded types (secret(), color())
3. Adds x-secret: true or x-color: true metadata to those fields
4. Returns the enhanced JSON Schema

// Simplified implementation
function toJsonSchema(zodSchema: z.ZodTypeAny): Record<string, unknown> {
  const jsonSchema = zodSchema.toJSONSchema();
  addSchemaMetadata(zodSchema, jsonSchema);  // Adds x-secret, x-color
  return jsonSchema;
}

Frontend: Specialized Field Rendering

The DynamicForm component in DynamicForm.tsx detects branded fields:

// Detect secret fields from x-secret metadata
const isSecret = propSchema["x-secret"];
if (isSecret) {
  // Render password input with show/hide toggle
  return <Input type={showPassword ? "text" : "password"} ... />;
}

// Detect color fields from x-color metadata
const isColor = propSchema["x-color"];
if (isColor) {
  // Render color picker with swatch and text input
  return <ColorPicker value={value} onChange={onChange} />;
}

Factory Functions Reference

The platform provides factory functions for creating Zod schemas with specialized metadata:

configString({ "x-secret": true }) - Sensitive Data

Use for passwords, API keys, tokens, and other sensitive data:

import { configString } from "@checkstack/backend-api";

const schema = z.object({
  apiKey: configString({ "x-secret": true }).describe("API authentication key"),
  password: configString({ "x-secret": true }).optional().describe("Optional password"),
});

Features:

• Renders as password input with show/hide toggle
• Values are encrypted at rest via ConfigService
• Redacted when returning config to frontend

configString({ "x-color": true }) - Hex Colors

Use for hex color values (e.g., brand colors, theme colors):

import { configString } from "@checkstack/backend-api";

const schema = z.object({
  // With default value
  primaryColor: configString({ "x-color": true }).default("#3b82f6").describe("Primary brand color"),
  // Optional without default
  accentColor: configString({ "x-color": true }).optional().describe("Accent color"),
});

Features:

• Renders as color picker with swatch + text input
• Validates hex format (#RGB or #RRGGBB)
• Supports optional default values

configString({ "x-options-resolver": ... }) - Dynamic Dropdowns

Use for fields that need to fetch options dynamically from the backend:

import { configString } from "@checkstack/backend-api";

const schema = z.object({
  // Basic options resolver
  projectKey: configString({
    "x-options-resolver": "projectOptions",
  }).describe("Jira project"),
  
  // With dependencies (refetches when dependent fields change)
  issueTypeId: configString({
    "x-options-resolver": "issueTypeOptions",
    "x-depends-on": ["projectKey"],
  }).describe("Issue type"),
  
  // With searchable dropdown for many options
  fieldKey: configString({
    "x-options-resolver": "fieldOptions",
    "x-depends-on": ["projectKey", "issueTypeId"],
    "x-searchable": true,
  }).describe("Jira field"),
});

Features:

• Renders as a dropdown that fetches options from backend
• x-options-resolver: Name of the resolver function to call
• x-depends-on: Array of field names that trigger refetch when changed
• x-searchable: When true, renders a searchable dropdown with filter input inside

Implementation requirements: The provider must implement getConnectionOptions() to handle resolver calls. See Integration Providers for details.

configString({ "x-hidden": true }) - Auto-populated Fields

Use for fields that are auto-populated and should not be shown in the form:

import { configString } from "@checkstack/backend-api";

const schema = z.object({
  // Hidden field (auto-populated)
  connectionId: configString({ "x-hidden": true }).describe("Connection ID (auto-populated)"),
  
  // Normal visible fields
  name: configString({}).describe("Subscription name"),
});

Features:

• Field is hidden from the form UI
• Value is typically set programmatically
• Useful for connection IDs or other auto-populated values

configString({ "x-editor-types": [...] }) - Multi-Type Editor

Use for string fields that support multiple input formats with dynamic editing modes:

import { configString } from "@checkstack/backend-api";

const schema = z.object({
  // HTTP request body with multiple format options
  body: configString({
    "x-editor-types": ["none", "raw", "json", "yaml", "xml", "formdata"],
  }).optional().describe("Request body"),

  // Template field with structured data support
  template: configString({
    "x-editor-types": ["json", "yaml", "xml"],
  }).describe("Template content"),

  // Simple template with just raw text
  bodyTemplate: configString({
    "x-editor-types": ["raw"],
  }).optional().describe("Custom body template"),

  // Documentation with markdown support
  notes: configString({
    "x-editor-types": ["raw", "markdown"],
  }).optional().describe("Notes or documentation"),
});

Available Editor Types:

• "none": Disabled input (value is cleared/undefined)
• "raw": Plain text textarea
• "json": JSON code editor with syntax highlighting and auto-indentation
• "yaml": YAML code editor with syntax highlighting and auto-indentation
• "xml": XML/HTML code editor with tag highlighting and smart tag splitting
• "markdown": Markdown editor with syntax highlighting
• "formdata": Key-value pair editor (URL-encoded format)

CodeEditor Features:

• Syntax Highlighting: Language-specific colors for keys, values, tags, and templates
• Smart Indentation: Custom Enter key behavior with proper indentation for each language
• Bracket/Tag Splitting: Pressing Enter between {}, [], or <tag></tag> properly splits them
• Template Support: Mustache-style `` syntax with autocomplete
• Line Numbers: Visible with proper gutter styling
• Full Click Area: Entire editor area is clickable (per official CodeMirror best practices)

Features:

• Dropdown selector when multiple types are available
• Auto-detects initial editor type from existing value
• Automatic format conversion when switching between types
• Template autocomplete ({{ syntax) when templateProperties are provided to DynamicForm
• All formats serialize to a single string for storage

Template Autocomplete: When the parent DynamicForm receives templateProperties, all applicable editor types (raw, json, yaml, xml, markdown) will show autocomplete suggestions when typing {{:

<DynamicForm
  schema={configSchema}
  value={formValue}
  onChange={setFormValue}
  templateProperties={[
    { path: "payload.incident.title", type: "string" },
    { path: "payload.incident.severity", type: "string" },
  ]}
/>

Secret Handling Best Practices

1. Marking Fields as Secrets

Use configString({ "x-secret": true }) for any sensitive data:

• Passwords
• API keys
• Authentication tokens
• Private keys
• Database connection strings with credentials

import { configString, configNumber } from "@checkstack/backend-api";

const schema = z.object({
  // Regular field
  timeout: configNumber({}).default(5000),
  
  // Secret field
  accessToken: configString({ "x-secret": true }).describe("OAuth access token"),
});

2. Optional vs Required Secrets

Secrets can be optional or required (via defaults):

const schema = z.object({
  // Optional secret (can be empty)
  password: configString({ "x-secret": true }).optional().describe("Password (optional)"),
  
  // Required secret (has default, but user should change it)
  apiKey: configString({ "x-secret": true }).default("").describe("API Key"),
});

3. Configuration Retrieval Security

When returning current configuration to the frontend for editing:

// ✅ CORRECT: Use getRedacted() to remove secrets
getConfiguration: os.getConfiguration.handler(async ({ context }) => {
  const config = await context.configService.getRedacted(
    pluginId,
    plugin.configSchema,
    plugin.configVersion
  );
  
  return { pluginId, config };  // Secrets are empty/undefined
}),

// ❌ WRONG: Exposes unredacted secrets to frontend
getConfiguration: os.getConfiguration.handler(async ({ context }) => {
  const config = await context.configService.get(...);
  return { pluginId, config };  // Security vulnerability!
}),

Testing

Verify schema conversion includes secret metadata:

import { describe, test, expect } from "bun:test";
import { toJsonSchema } from "@checkstack/backend-api";
import { myPluginConfigSchema } from "./schema";

describe("Plugin Config Schema", () => {
  test("should mark password field as secret", () => {
    const jsonSchema = toJsonSchema(myPluginConfigSchema);
    
    expect(jsonSchema.properties.password["x-secret"]).toBe(true);
  });
});

Common Mistakes

❌ Using Native Zod Method

// WRONG: No x-secret metadata
configSchema: zod.toJSONSchema(p.configSchema)

❌ Forgetting to Import

// WRONG: Using wrong function
import { zod } from "@checkstack/backend-api";
configSchema: zod.toJSONSchema(p.configSchema)

❌ Not Using secret() Helper

// WRONG: Regular string field for sensitive data
password: z.string().describe("Password")

✅ Correct Pattern

import { toJsonSchema, configString } from "@checkstack/backend-api";

// In schema
password: configString({ "x-secret": true }).describe("Password")

// In router
configSchema: toJsonSchema(p.configSchema)

Reference Implementations

Good examples to follow:

• auth-backend/router.ts - Uses toJsonSchema and getRedacted
• queue-backend/router.ts - Uses toJsonSchema
• auth-ldap-backend/strategy.ts - Uses secret() helper

Summary

Always follow these rules when exposing config schemas to the frontend:

1. ✅ Use toJsonSchema() from @checkstack/backend-api, not Zod’s native method
2. ✅ Mark sensitive fields with configString({ "x-secret": true }) in your schemas
3. ✅ Use ConfigService.getRedacted() when returning current config to frontend
4. ✅ Test that secret fields have x-secret: true metadata

This ensures:

• Password fields render correctly with show/hide toggles
• Secrets never leak to the frontend
• Consistent security behavior across all plugins

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