n8n-io/n8n · error · Error

Guardrail "${this.name}" requires a strategy

Error message

Guardrail "${this.name}" requires a strategy

What it means

Thrown by Guardrail.build() when .strategy(...) was never called. Even with a type set, the runtime needs a strategy (e.g. block/redact) to know what action to take when the guard fires.

Source

Thrown at packages/@n8n/agents/src/sdk/guardrail.ts:40

	strategy(strategy: GuardrailStrategy): this {
		this.strategyType = strategy;
		return this;
	}

	detect(types: PiiDetectionType[]): this {
		this.detectionTypes = types;
		return this;
	}

	threshold(value: number): this {
		this.thresholdValue = value;
		return this;
	}

	build(): BuiltGuardrail {
		if (!this.guardType) throw new Error(`Guardrail "${this.name}" requires a type`);
		if (!this.strategyType) throw new Error(`Guardrail "${this.name}" requires a strategy`);

		return {
			name: this.name,
			guardType: this.guardType,
			strategy: this.strategyType,
			_config: {
				detectionTypes: this.detectionTypes,
				threshold: this.thresholdValue,
			},
		};
	}
}

View on GitHub (pinned to 5ac6606e81)

Solutions

1. Call .strategy('block' | 'redact' | other GuardrailStrategy) before consumption.
2. Validate each Guardrail with a build() in tests.
3. Co-locate .type() and .strategy() in builder helpers so neither is forgotten.

Example fix

// before
const g = new Guardrail('pii-out').type('output');
// after
const g = new Guardrail('pii-out').type('output').strategy('block');

function assertGuardStrategySet(g: { strategyType?: string }) {
  if (!g.strategyType) throw new Error('Guardrail missing .strategy()');
}

function guardHasStrategy(g: { strategyType?: string }): g is { strategyType: string } {
  return typeof g.strategyType === 'string' && g.strategyType.length > 0;
}

When it happens

Trigger: Constructing new Guardrail('name'), calling .type(...) but not .strategy(...), then triggering build.

Common situations: Same shape as 69 — refactors, conditionals, copy-paste that lose the .strategy() call.

Related errors

• Guardrail "${this.name}" requires a type
• Eval "${this.evalName}" requires either .check() or .judge()
• Tool name is required
• Tool "${this.name}" requires a description
• Tool "${this.name}" requires an input schema

AI-assisted analysis of n8n-io/n8n@5ac6606e81 (2026-08-12). Data as JSON: /api/errors/68ca6c2c56694abf. Report an issue: GitHub.