# ParamStash

**Kind:** Type

**Source:** [`src/router.ts`](https://github.com/honojs/hono/blob/main/src/router.ts#L61)

Type representing a stash of parameters.

`ParamStash` represents the parameters collected during router matching. It acts as the typed value passed between route matching logic and code that handles the matched route.

## Definition

```ts
string[]
```

## Diagram

```mermaid
graph LR
  Route[Route match] --> Stash[ParamStash]
  Stash --> Handler[Route handler]
```

## Usage

```ts
import type { ParamStash } from "./router";

function handleMatchedRoute(params: ParamStash): ParamStash {
  // Pass the matched parameter stash to downstream route logic.
  return params;
}
```

## AI Coding Instructions

- Import `ParamStash` with `import type` when it is only used for TypeScript annotations.
- Keep parameter collection and parameter consumption typed as `ParamStash` at router boundaries.
- Do not replace `ParamStash` with an untyped object when forwarding matched route parameters.
- Update route matching code and handler signatures together when the parameter stash shape changes.