diff --git a/gitnexus/src/core/evolver/evolver-runtime.ts b/gitnexus/src/core/evolver/evolver-runtime.ts
new file mode 100644
index 000000000..13a350fc2
--- /dev/null
+++ b/gitnexus/src/core/evolver/evolver-runtime.ts
@@ -0,0 +1,199 @@
+import type {
+  BaselineProfile,
+  EnvironmentSnapshot,
+  EvaluationReport,
+  EvolutionPlan,
+  GateDecision,
+  GoalSpec,
+  MutationType,
+  PromotionRecord,
+  ResourceBudget,
+  TrialResult,
+  VariantSpec,
+} from './types.js';
+import type { SandboxRunner } from './sandbox-runner.js';
+import type { InMemoryEvolutionMemory } from './evolution-memory.js';
+import { applyPromotion } from './promotion-controller.js';
+import { decidePromotion } from './safety-gate.js';
+import { decideResourceUse } from './resource-manager.js';
+import { evaluateVariant } from './metric-evaluator.js';
+import { generateVariants } from './variant-generator.js';
+import { runSandboxTrial } from './sandbox-runner.js';
+
+export interface EvolverRuntimeConfig {
+  memory: InMemoryEvolutionMemory;
+  sandboxRunner: SandboxRunner;
+  currentParameters: Record<string, unknown>;
+  allowedMutationTypes?: MutationType[];
+}
+
+export interface EvolverRuntimeResult {
+  promotionRecord: PromotionRecord | null;
+  gateDecision: GateDecision;
+  evaluationReport: EvaluationReport;
+  trialResult: TrialResult;
+}
+
+export interface EvolverRuntime {
+  runEvolution(
+    goal: GoalSpec,
+    snapshot: EnvironmentSnapshot,
+    baseline: BaselineProfile,
+  ): Promise<EvolverRuntimeResult>;
+}
+
+export function createEvolverRuntime(config: EvolverRuntimeConfig): EvolverRuntime {
+  return {
+    async runEvolution(
+      goal: GoalSpec,
+      snapshot: EnvironmentSnapshot,
+      baseline: BaselineProfile,
+    ): Promise<EvolverRuntimeResult> {
+      const plan = buildPlan(goal, config.allowedMutationTypes);
+      const variants = generateVariants(plan, config.currentParameters);
+
+      const variant = variants[0];
+
+      memoryAdd(config.memory, 'variant', variant.id, goal.id, `Generated ${variant.mutationType} variant`, variant);
+
+      const protocol = { id: `${plan.id}-protocol`, maxDurationMs: plan.resourceBudget.maxDurationMs };
+
+      const resourceDecision = decideResourceUse(
+        {
+          variant,
+          requestedUsage: {
+            durationMs: protocol.maxDurationMs,
+            computeUnits: 1,
+            apiCostUsd: 0,
+            storageBytes: 256,
+          },
+          activeRuns: 1,
+          activeHighRiskVariants: variant.riskLevel === 'high' ? 1 : 0,
+        },
+        plan.resourceBudget,
+        snapshot.resourceUsage,
+      );
+
+      if (!resourceDecision.allowed) {
+        const failedTrial = buildResourceDeniedTrial(variant, protocol);
+        memoryAdd(config.memory, 'trial', variant.id, goal.id, 'Resource denied', failedTrial);
+        const report = buildRejectedReport(variant, baseline, 'resource denied');
+        const gate = decidePromotion(variant, report);
+        return { promotionRecord: null, gateDecision: gate, evaluationReport: report, trialResult: failedTrial };
+      }
+
+      const trial = await runSandboxTrial(variant, protocol, config.sandboxRunner, plan.resourceBudget);
+      memoryAdd(config.memory, 'trial', variant.id, goal.id, `Trial completed with ${trial.errors.length} errors`, trial);
+
+      const report = evaluateVariant({
+        id: `evaluation-${variant.id}`,
+        variant,
+        baseline,
+        trial,
+        targetMetrics: goal.targetMetrics,
+        budget: plan.resourceBudget,
+        safetyFindings: extractSafetyFindings(snapshot),
+        rollbackPassed: variant.mutationType === 'structure' || variant.rollbackPlan.operations.length > 0,
+      });
+      memoryAdd(config.memory, 'evaluation', variant.id, goal.id, `Verdict: ${report.verdict}`, report);
+
+      const gate = decidePromotion(variant, report);
+      memoryAdd(config.memory, 'gate', variant.id, goal.id, `Decision: ${gate.decision}`, gate);
+
+      let promotionRecord: PromotionRecord | null = null;
+      if (gate.decision === 'allow') {
+        promotionRecord = applyPromotion(config.currentParameters, variant, gate);
+        if (promotionRecord) {
+          memoryAdd(config.memory, 'promotion', variant.id, goal.id, 'Variant promoted', promotionRecord);
+        }
+      }
+
+      return { promotionRecord, gateDecision: gate, evaluationReport: report, trialResult: trial };
+    },
+  };
+}
+
+function buildPlan(goal: GoalSpec, allowedMutationTypes?: MutationType[]): EvolutionPlan {
+  return {
+    id: `plan-${goal.id}`,
+    goalId: goal.id,
+    hypothesis: `Evolve towards ${goal.objective}`,
+    targetObject: {
+      id: `target-${goal.id}`,
+      kind: 'parameter-set',
+      description: goal.objective,
+    },
+    allowedMutationTypes: allowedMutationTypes ?? ['parameter'],
+    evaluationProtocolId: `protocol-${goal.id}`,
+    resourceBudget: defaultBudget(),
+  };
+}
+
+function defaultBudget(): ResourceBudget {
+  return {
+    maxDurationMs: 5000,
+    maxComputeUnits: 100,
+    maxApiCostUsd: 10,
+    maxStorageBytes: 10240,
+    maxConcurrency: 4,
+    maxHighRiskVariants: 2,
+  };
+}
+
+function extractSafetyFindings(snapshot: EnvironmentSnapshot) {
+  return snapshot.signals
+    .filter((s) => s.kind === 'safety')
+    .map((s) => ({ id: s.id, severity: s.severity, message: s.description }));
+}
+
+function buildResourceDeniedTrial(variant: VariantSpec, protocol: { id: string }): TrialResult {
+  return {
+    id: `trial-${variant.id}-${protocol.id}`,
+    variantId: variant.id,
+    protocolId: protocol.id,
+    metrics: [],
+    resourceUsage: { durationMs: 0, computeUnits: 0, apiCostUsd: 0, storageBytes: 0 },
+    errors: [
+      {
+        id: `error-trial-${variant.id}-${protocol.id}`,
+        type: 'resource-exhaustion',
+        message: 'resource request denied',
+        occurredAt: '2026-05-25T00:00:00.000Z',
+        variantId: variant.id,
+      },
+    ],
+    completedAt: '2026-05-25T00:00:00.000Z',
+  };
+}
+
+function buildRejectedReport(variant: VariantSpec, baseline: BaselineProfile, reason: string): EvaluationReport {
+  return {
+    id: `evaluation-${variant.id}`,
+    variantId: variant.id,
+    baselineId: baseline.id,
+    metricDeltas: [],
+    regressions: [],
+    resourceCost: { durationMs: 0, computeUnits: 0, apiCostUsd: 0, storageBytes: 0 },
+    safetyFindings: [{ id: `safety-${variant.id}`, severity: 'high', message: reason }],
+    verdict: 'reject',
+  };
+}
+
+function memoryAdd(
+  memory: InMemoryEvolutionMemory,
+  kind: 'variant' | 'trial' | 'evaluation' | 'gate' | 'promotion',
+  variantId: string,
+  goalId: string,
+  summary: string,
+  payload: unknown,
+): void {
+  memory.add({
+    id: `mem-${kind}-${variantId}`,
+    variantId,
+    goalId,
+    kind,
+    summary,
+    createdAt: '2026-05-25T00:00:00.000Z',
+    payload,
+  });
+}
diff --git a/gitnexus/src/core/evolver/index.ts b/gitnexus/src/core/evolver/index.ts
index 5b4dc683d..f3a0c7b28 100644
--- a/gitnexus/src/core/evolver/index.ts
+++ b/gitnexus/src/core/evolver/index.ts
@@ -7,3 +7,4 @@ export * from './safety-gate.js';
 export * from './promotion-controller.js';
 export * from './evolution-memory.js';
 export * from './error-corrector.js';
+export * from './evolver-runtime.js';
diff --git a/gitnexus/test/unit/evolver/evolver-runtime.test.ts b/gitnexus/test/unit/evolver/evolver-runtime.test.ts
new file mode 100644
index 000000000..dced1d9d3
--- /dev/null
+++ b/gitnexus/test/unit/evolver/evolver-runtime.test.ts
@@ -0,0 +1,130 @@
+import { describe, expect, it } from 'vitest';
+import { createEvolverRuntime } from '../../../src/core/evolver/index.js';
+import type {
+  BaselineProfile,
+  EnvironmentSnapshot,
+  GoalSpec,
+  InMemoryEvolutionMemory,
+  SandboxRunner,
+} from '../../../src/core/evolver/index.js';
+
+const capturedAt = '2026-05-25T00:00:00.000Z';
+
+const goal: GoalSpec = {
+  id: 'goal-1',
+  name: 'Improve retrieval accuracy',
+  objective: 'Increase task success rate by adjusting retrieval parameters',
+  priority: 1,
+  targetMetrics: [
+    {
+      metricId: 'task_success_rate',
+      direction: 'increase',
+      minDelta: 0.03,
+      maxRegression: 0.02,
+    },
+  ],
+  constraints: [],
+  stopConditions: ['task_success_rate >= 0.90'],
+};
+
+const baseline: BaselineProfile = {
+  id: 'baseline-1',
+  goalId: 'goal-1',
+  capturedAt,
+  metrics: [
+    { metricId: 'task_success_rate', value: 0.72, capturedAt },
+  ],
+  resourceUsage: { durationMs: 0, computeUnits: 0, apiCostUsd: 0, storageBytes: 0 },
+};
+
+const snapshot: EnvironmentSnapshot = {
+  id: 'snapshot-1',
+  capturedAt,
+  signals: [],
+  performance: [{ metricId: 'task_success_rate', value: 0.72, capturedAt }],
+  errors: [],
+  resourceUsage: { durationMs: 0, computeUnits: 0, apiCostUsd: 0, storageBytes: 0 },
+};
+
+function successRunner(): SandboxRunner {
+  return async (variant, protocol) => ({
+    metrics: [
+      { metricId: 'task_success_rate', value: 0.82, capturedAt },
+    ],
+    resourceUsage: { durationMs: 120, computeUnits: 1, apiCostUsd: 0, storageBytes: 256 },
+  });
+}
+
+function regressionRunner(): SandboxRunner {
+  return async (variant, protocol) => ({
+    metrics: [
+      { metricId: 'task_success_rate', value: 0.60, capturedAt },
+    ],
+    resourceUsage: { durationMs: 120, computeUnits: 1, apiCostUsd: 0, storageBytes: 256 },
+  });
+}
+
+describe('createEvolverRuntime', () => {
+  it('promotes a safe parameter variant and updates target parameters', async () => {
+    const memory: InMemoryEvolutionMemory = new (await import('../../../src/core/evolver/index.js')).InMemoryEvolutionMemory();
+    const currentParameters = { retrieval: { topK: 5 } };
+
+    const runtime = createEvolverRuntime({
+      memory,
+      sandboxRunner: successRunner(),
+      currentParameters,
+    });
+
+    const result = await runtime.runEvolution(goal, snapshot, baseline);
+
+    expect(result.promotionRecord).not.toBeNull();
+    expect(result.promotionRecord!.variantId).toContain('parameter');
+    expect(currentParameters.retrieval.topK).toBe(6);
+    expect(result.gateDecision.decision).toBe('allow');
+
+    const memoryRecords = memory.queryByKind('variant');
+    expect(memoryRecords.length).toBeGreaterThanOrEqual(1);
+  });
+
+  it('rejects a regressive variant without mutating target', async () => {
+    const { InMemoryEvolutionMemory: Mem } = await import('../../../src/core/evolver/index.js');
+    const memory = new Mem();
+    const currentParameters = { retrieval: { topK: 5 } };
+
+    const runtime = createEvolverRuntime({
+      memory,
+      sandboxRunner: regressionRunner(),
+      currentParameters,
+    });
+
+    const result = await runtime.runEvolution(goal, snapshot, baseline);
+
+    expect(result.gateDecision.decision).toBe('reject');
+    expect(currentParameters.retrieval.topK).toBe(5);
+  });
+
+  it('returns needs-review for structure variant', async () => {
+    const { InMemoryEvolutionMemory: Mem } = await import('../../../src/core/evolver/index.js');
+    const memory = new Mem();
+    const currentParameters = { retrieval: { topK: 5 } };
+
+    const structureGoal: GoalSpec = {
+      ...goal,
+      id: 'goal-structure',
+      constraints: [],
+      stopConditions: [],
+    };
+
+    const runtime = createEvolverRuntime({
+      memory,
+      sandboxRunner: successRunner(),
+      currentParameters,
+      allowedMutationTypes: ['structure'],
+    });
+
+    const result = await runtime.runEvolution(structureGoal, snapshot, baseline);
+
+    expect(result.gateDecision.decision).toBe('needs-review');
+    expect(currentParameters.retrieval.topK).toBe(5);
+  });
+});