> ## Documentation Index
> Fetch the complete documentation index at: https://docs.agentfront.dev/llms.txt
> Use this file to discover all available pages before exploring further.
# Decorators Overview
> FrontMCP uses TypeScript decorators to define MCP server components declaratively. All decorators follow a metadata-first design with Zod schema validation.
## Decorator Categories
* `@FrontMcp` - Bootstrap MCP server
* `@App` - Define application modules
* `@Tool` - Define MCP tools
* `@Resource` / `@ResourceTemplate` - Define resources
* `@Prompt` - Define prompt templates
* `@Agent` - Define autonomous agents
* `@Skill` - Define knowledge packages
* `@Job` - Define executable jobs
* `@Workflow` - Define multi-step workflows
* `@Plugin` - Create plugins
* `@Provider` - Dependency injection
* `@Adapter` - Framework adapters
* `@Stage` - Define flow stages
* `@Will` - Before-stage hooks
* `@Did` - After-stage hooks
* `@Around` - Wrap-stage hooks
## Class-Based vs Function-Based
Most entry decorators support both patterns:
### Class-Based (Recommended for Complex Logic)
```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
import { Tool, ToolContext } from '@frontmcp/sdk';
import { z } from 'zod';
@Tool({
name: 'get_user',
description: 'Fetch user by ID',
inputSchema: { userId: z.string() },
})
class GetUserTool extends ToolContext {
async execute(input: { userId: string }) {
const db = this.get(DatabaseToken);
return db.findUser(input.userId);
}
}
```
### Function-Based (Simpler Definitions)
```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
import { tool } from '@frontmcp/sdk';
import { z } from 'zod';
const getUserTool = tool({
name: 'get_user',
description: 'Fetch user by ID',
inputSchema: { userId: z.string() },
})((input, ctx) => {
const db = ctx.get(DatabaseToken);
return db.findUser(input.userId);
});
```
## Type Inference
FrontMCP provides full type inference for inputs and outputs:
```typescript theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
import { Tool, ToolContext, ToolInputOf, ToolOutputOf } from '@frontmcp/sdk';
import { z } from 'zod';
const metadata = {
name: 'calculate',
inputSchema: { a: z.number(), b: z.number() },
outputSchema: z.object({ result: z.number() }),
} as const;
// Types are inferred automatically
type Input = ToolInputOf; // { a: number; b: number }
type Output = ToolOutputOf; // { result: number }
@Tool(metadata)
class CalculateTool extends ToolContext<
typeof metadata.inputSchema,
typeof metadata.outputSchema
> {
async execute(input: Input): Promise