Interceptors

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Interceptors wrap controller execution and can transform responses or return early.

Common Uses

response envelopes
timing and metrics
cache short-circuiting
output normalization

Typical Shape

class EnvelopeInterceptor {
    async intercept(_context: unknown, next: () => Promise<unknown>) {
        const value = await next();
        return { ok: true, data: value };
    }
}

Registering Interceptors

Global: createApp({ interceptors: [...] })
Controller: @UseInterceptors(...)
Method: @UseInterceptors(...)

Short-Circuit Pattern

An interceptor may return a Response directly to stop downstream execution.

Response Validation Interaction

If validateResponse is enabled, transformed output still needs to match the declared @Returns schema for the final status code.

Example

See examples/07_interceptors/server.ts.