fix(core): forward pre_output gate on_fail into compiled output

packages/core/compiler.test.ts

@@ -553,6 +553,48 @@ describe("CompiledStep.executionPlan carries parallel execution through compilat
 	});
 });
 
+// =============================================================================
+// pre_output gate on_fail survives compilation (issue #72)
+// =============================================================================
+
+describe("pre_output gate carries on_fail through compilation", () => {
+	const actions: OnFailAction[] = ["retry", "escalate", "skip", "abort", "revise"];
+
+	// A step with no verification, so qualityGates[0] is the pre_output gate.
+	function specWithGate(onFail?: OnFailAction): LogicSpec {
+		return {
+			...makeSpec({ scored: { description: "Scored step" } }),
+			quality_gates: {
+				pre_output: [
+					{
+						name: "confidence-check",
+						check: "{{ output.score >= 0.8 }}",
+						message: "Score too low",
+						...(onFail !== undefined ? { on_fail: onFail } : {}),
+					},
+				],
+			},
+		};
+	}
+
+	it.each(actions)("forwards on_fail: %s onto the failing pre_output gate result", (onFail) => {
+		const result = compileStep(specWithGate(onFail), "scored", makeCtx());
+		expect(result.qualityGates).toHaveLength(1);
+		expect(result.qualityGates[0]!({ score: 0.5 })).toEqual({
+			passed: false,
+			message: "Score too low",
+			onFail,
+		});
+	});
+
+	it("omits onFail when the pre_output gate has no authored on_fail", () => {
+		const result = compileStep(specWithGate(), "scored", makeCtx());
+		const failed = result.qualityGates[0]!({ score: 0.5 });
+		expect(failed).toEqual({ passed: false, message: "Score too low" });
+		expect(failed).not.toHaveProperty("onFail");
+	});
+});
+
 // =============================================================================
 // Output Format in systemPromptSegment
 // =============================================================================

packages/core/compiler.ts

@@ -15,6 +15,7 @@ import type {
 	ExecutionPlan,
 	JsonSchemaObject,
 	LogicSpec,
+	OnFailAction,
 	QualityGateValidator,
 	Reasoning,
 	RetryConfig,
@@ -255,14 +256,27 @@ function compileSelfReflection(
  * Compile a gate check expression into a QualityGateValidator function.
  * Uses the expression engine's evaluate() to evaluate the check expression
  * with the step output injected as `{ output }` in the expression context.
+ *
+ * When the gate carries an authored on_fail recovery action, it is forwarded
+ * onto the failing result so a runtime can recover what action a failed gate
+ * should trigger without reaching back into the un-compiled spec. Omitted when
+ * the author did not specify one (the source field is optional).
  */
-function compileGateValidator(checkExpression: string, message?: string): QualityGateValidator {
+function compileGateValidator(
+	checkExpression: string,
+	message?: string,
+	onFail?: OnFailAction,
+): QualityGateValidator {
 	return (output: unknown) => {
 		const result = evaluate(checkExpression, { output });
 		if (result) {
 			return { passed: true };
 		}
-		return { passed: false, ...(message ? { message } : {}) };
+		return {
+			passed: false,
+			...(message ? { message } : {}),
+			...(onFail !== undefined ? { onFail } : {}),
+		};
 	};
 }
 
@@ -398,7 +412,7 @@ export function compileStep(
 			}
 			if (spec.quality_gates?.pre_output) {
 				for (const gate of spec.quality_gates.pre_output) {
-					gates.push(compileGateValidator(gate.check, gate.message));
+					gates.push(compileGateValidator(gate.check, gate.message, gate.on_fail));
 				}
 			}
 			return gates;
@@ -463,7 +477,7 @@ export function compileWorkflow(spec: LogicSpec, context: WorkflowContext): Comp
 	const globalGates: QualityGateValidator[] = [];
 	if (spec.quality_gates?.pre_output) {
 		for (const gate of spec.quality_gates.pre_output) {
-			globalGates.push(compileGateValidator(gate.check, gate.message));
+			globalGates.push(compileGateValidator(gate.check, gate.message, gate.on_fail));
 		}
 	}
 

packages/core/types.ts

@@ -640,6 +640,8 @@ export interface QualityGateResult {
 	passed: boolean;
 	/** Human-readable reason surfaced when the check fails */
 	message?: string;
+	/** Recovery action authored on the gate, surfaced when the gate fails */
+	onFail?: OnFailAction;
 }
 
 /** Runtime quality gate validator function (v1.1 Compiler) */