diff --git a/server/src/addie/jobs/compliance-heartbeat.ts b/server/src/addie/jobs/compliance-heartbeat.ts
index b352dcb3e26..3dcb6415fe4 100644
--- a/server/src/addie/jobs/compliance-heartbeat.ts
+++ b/server/src/addie/jobs/compliance-heartbeat.ts
@@ -485,6 +485,7 @@ export async function runComplianceHeartbeatJob(
           agent_url: agent.agent_url,
           requested_compliance_target: runTarget.requested,
           adcp_version: runTarget.version,
+          runner_capability_version: LIBRARY_VERSION,
           lifecycle_stage: agent.lifecycle_stage as LifecycleStage,
           overall_status: 'failing',
           headline,
diff --git a/server/src/addie/services/compliance-testing.ts b/server/src/addie/services/compliance-testing.ts
index 6392dea59f1..69a5c935f81 100644
--- a/server/src/addie/services/compliance-testing.ts
+++ b/server/src/addie/services/compliance-testing.ts
@@ -1460,6 +1460,7 @@ export function complianceResultToDbInput(
     requested_compliance_target: (result as ComplianceResult & { requested_compliance_target?: string })
       .requested_compliance_target ?? null,
     adcp_version: result.adcp_version ?? null,
+    runner_capability_version: result.summary.runner_capability_version ?? null,
     lifecycle_stage: lifecycleStage,
     overall_status,
     headline: result.summary.headline,
diff --git a/server/src/db/compliance-db.ts b/server/src/db/compliance-db.ts
index 32067838912..97b6e9710a5 100644
--- a/server/src/db/compliance-db.ts
+++ b/server/src/db/compliance-db.ts
@@ -117,6 +117,7 @@ export interface ComplianceRun {
   agent_url: string;
   requested_compliance_target: string | null;
   adcp_version: string | null;
+  runner_capability_version: string | null;
   lifecycle_stage: LifecycleStage;
   overall_status: OverallRunStatus;
   headline: string | null;
@@ -285,6 +286,7 @@ export interface RecordComplianceRunInput {
   agent_url: string;
   requested_compliance_target?: string | null;
   adcp_version?: string | null;
+  runner_capability_version?: string | null;
   lifecycle_stage: LifecycleStage;
   overall_status: OverallRunStatus;
   headline?: string;
@@ -696,8 +698,9 @@ export class ComplianceDatabase {
           tracks_skipped, tracks_partial, agent_profile_json,
           observations_json, triggered_by, triggered_org_id, dry_run,
           notices_json, refresh_operation_id, agent_quality_evaluation_id,
-          completeness, is_authoritative, storyboard_statuses_json, provenance_json
-        ) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15, $16, $17, $18, $19, $20, $21, $22, $23, $24)
+          completeness, is_authoritative, storyboard_statuses_json, provenance_json,
+          runner_capability_version
+        ) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14, $15, $16, $17, $18, $19, $20, $21, $22, $23, $24, $25)
         ON CONFLICT DO NOTHING
         RETURNING *`,
         [
@@ -725,6 +728,7 @@ export class ComplianceDatabase {
           authoritative,
           JSON.stringify(input.storyboard_statuses ?? []),
           input.provenance_json ? JSON.stringify(input.provenance_json) : null,
+          input.runner_capability_version ?? null,
         ],
       );
       let run = runResult.rows[0] as ComplianceRun | undefined;
diff --git a/server/src/db/migrations/608_agent_compliance_runner_version.sql b/server/src/db/migrations/608_agent_compliance_runner_version.sql
new file mode 100644
index 00000000000..07ade74fba4
--- /dev/null
+++ b/server/src/db/migrations/608_agent_compliance_runner_version.sql
@@ -0,0 +1,5 @@
+ALTER TABLE agent_compliance_runs
+  ADD COLUMN IF NOT EXISTS runner_capability_version TEXT;
+
+COMMENT ON COLUMN agent_compliance_runs.runner_capability_version IS
+  'Runner capability version recorded at execution time; NULL when not recorded, including historical runs.';
diff --git a/server/src/routes/registry-api.ts b/server/src/routes/registry-api.ts
index 3a61b9fba1b..726fd55413b 100644
--- a/server/src/routes/registry-api.ts
+++ b/server/src/routes/registry-api.ts
@@ -7555,6 +7555,7 @@ export function createRegistryApiRouters(config: RegistryApiConfig): {
           provenance: run.provenance_json ?? null,
           requested_compliance_target: run.requested_compliance_target ?? null,
           adcp_version: run.adcp_version ?? null,
+          runner_capability_version: run.runner_capability_version ?? null,
           overall_status: run.overall_status,
           headline: publicComplianceHeadline(run.overall_status, run.headline),
           tracks_passed: run.tracks_passed,
diff --git a/server/src/schemas/registry.ts b/server/src/schemas/registry.ts
index d2b2e69c6af..ff05d16d501 100644
--- a/server/src/schemas/registry.ts
+++ b/server/src/schemas/registry.ts
@@ -1497,6 +1497,9 @@ export const ComplianceRunSchema = z
     is_authoritative: z.boolean().optional(),
     requested_compliance_target: z.string().nullable().optional(),
     adcp_version: z.string().nullable().optional(),
+    runner_capability_version: z.string().nullable().optional().openapi({
+      description: "Runner capability version recorded at execution time, separate from the AdCP version under test. Null when not recorded, including historical runs.",
+    }),
     overall_status: z.string(),
     headline: z.string().nullable(),
     tracks_passed: z.number().int(),
diff --git a/server/tests/integration/registry-api-compliance-verdict-source.test.ts b/server/tests/integration/registry-api-compliance-verdict-source.test.ts
index 4c20c2b9d31..5135f219f00 100644
--- a/server/tests/integration/registry-api-compliance-verdict-source.test.ts
+++ b/server/tests/integration/registry-api-compliance-verdict-source.test.ts
@@ -288,6 +288,61 @@ describe('GET /api/registry/agents/:encodedUrl/compliance — owner-scope gate (
 
   const endpoint = `/api/registry/agents/${encodeURIComponent(AGENT_URL)}/compliance`;
 
+  it('returns null for a historical run without a recorded runner version', async () => {
+    const res = await request(app).get(`${endpoint}/history`);
+
+    expect(res.status).toBe(200);
+    expect(res.body.runs).toEqual([
+      expect.objectContaining({ id: complianceRunId, runner_capability_version: null }),
+    ]);
+  });
+
+  it('persists each runner version through real writes and history reads, including partial runs', async () => {
+    const agentUrl = `https://runner-version-${RUN_SUFFIX}.example.com/mcp`;
+    const db = new ComplianceDatabase();
+    const expectedRuns = [];
+
+    try {
+      for (const [overallStatus, runnerVersion] of [
+        ['passing', '14.0.0-rc.12'],
+        ['partial', '14.0.0-rc.13'],
+        ['failing', null],
+      ] as const) {
+        const { run } = await db.recordComplianceRun({
+          agent_url: agentUrl,
+          requested_compliance_target: '3.1',
+          adcp_version: '3.1.0',
+          runner_capability_version: runnerVersion,
+          lifecycle_stage: 'testing',
+          overall_status: overallStatus,
+          tracks_json: [],
+          tracks_passed: 0,
+          tracks_failed: 0,
+          tracks_skipped: 0,
+          tracks_partial: 0,
+          triggered_by: 'manual',
+          dry_run: false,
+        });
+        expect(run.runner_capability_version).toBe(runnerVersion);
+        expectedRuns.push(expect.objectContaining({
+          id: run.id,
+          overall_status: overallStatus,
+          adcp_version: '3.1.0',
+          runner_capability_version: runnerVersion,
+        }));
+      }
+
+      const res = await request(app)
+        .get(`/api/registry/agents/${encodeURIComponent(agentUrl)}/compliance/history`);
+      expect(res.status).toBe(200);
+      expect(res.body.count).toBe(3);
+      expect(res.body.runs).toEqual(expect.arrayContaining(expectedRuns));
+    } finally {
+      await pool.query('DELETE FROM agent_compliance_status WHERE agent_url = $1', [agentUrl]);
+      await pool.query('DELETE FROM agent_compliance_runs WHERE agent_url = $1', [agentUrl]);
+    }
+  });
+
   const OWNER_ONLY_KEYS = [
     'verdict_source',
     'membership_tier',
diff --git a/server/tests/unit/compliance-heartbeat.test.ts b/server/tests/unit/compliance-heartbeat.test.ts
index 21671a831c7..deb295b2e27 100644
--- a/server/tests/unit/compliance-heartbeat.test.ts
+++ b/server/tests/unit/compliance-heartbeat.test.ts
@@ -1,4 +1,5 @@
 import { beforeEach, describe, expect, it, vi } from 'vitest';
+import { LIBRARY_VERSION } from '@adcp/sdk';
 
 const mocks = vi.hoisted(() => ({
   getAgentsDueForCheck: vi.fn(),
@@ -565,6 +566,26 @@ describe('runComplianceHeartbeatJob', () => {
     });
   });
 
+  it('records the invoking runner version when comply throws without a result', async () => {
+    mocks.comply.mockRejectedValueOnce(new Error('Timed out'));
+
+    const { runComplianceHeartbeatJob } = await import('../../src/addie/jobs/compliance-heartbeat.js');
+    const result = await runComplianceHeartbeatJob({ limit: 1 });
+
+    expect(result).toEqual({ checked: 0, passed: 0, failed: 0, skipped: 1 });
+    expect(mocks.complianceResultToDbInput).not.toHaveBeenCalled();
+    expect(mocks.recordComplianceRun).toHaveBeenCalledExactlyOnceWith(
+      expect.objectContaining({
+        agent_url: 'https://agent.example.com/mcp',
+        adcp_version: target.version,
+        runner_capability_version: LIBRARY_VERSION,
+        overall_status: 'failing',
+        triggered_by: 'heartbeat',
+        dry_run: false,
+      }),
+    );
+  });
+
   it('records malformed saved Basic auth as audit-only setup evidence', async () => {
     mocks.comply.mockRejectedValueOnce(new Error('step.auth.basic.username must be a non-empty string'));
 
diff --git a/server/tests/unit/compliance-testing-effective-run-status.test.ts b/server/tests/unit/compliance-testing-effective-run-status.test.ts
index 44a89af9c0e..095e2c4c38b 100644
--- a/server/tests/unit/compliance-testing-effective-run-status.test.ts
+++ b/server/tests/unit/compliance-testing-effective-run-status.test.ts
@@ -55,6 +55,34 @@ function makeResult(tracks: ReturnType<typeof makeTrack>[], overallStatus = 'par
   };
 }
 
+describe('complianceResultToDbInput runner version', () => {
+  it.each([
+    ['pass', 'passing'],
+    ['partial', 'partial'],
+    ['fail', 'failing'],
+  ])('preserves the emitted version for %s results', (trackStatus, overallStatus) => {
+    const baseResult = makeResult([makeTrack(trackStatus)], overallStatus);
+    const result = {
+      ...baseResult,
+      adcp_version: '3.1.0',
+      summary: { ...baseResult.summary, runner_capability_version: '14.0.0-rc.12' },
+    };
+    const out = complianceResultToDbInput(result as any, 'https://agent.example.com/mcp', 'production');
+
+    expect(out.runner_capability_version).toBe('14.0.0-rc.12');
+    expect(out.adcp_version).toBe('3.1.0');
+    expect(out.overall_status).toBe(overallStatus);
+  });
+
+  it.each([{}, { runner_capability_version: null }])('does not invent a missing runner version: %j', fields => {
+    const baseResult = makeResult([makeTrack('pass')], 'passing');
+    const result = { ...baseResult, summary: { ...baseResult.summary, ...fields } };
+    const out = complianceResultToDbInput(result as any, 'https://agent.example.com/mcp', 'production');
+
+    expect(out.runner_capability_version).toBeNull();
+  });
+});
+
 describe('complianceResultToDbInput — effectiveRunStatus', () => {
   it('promotes all-silent to passing with zero partial/failed counters', () => {
     const result = makeResult([makeTrack('silent'), makeTrack('silent')], 'partial');
diff --git a/static/openapi/registry.yaml b/static/openapi/registry.yaml
index b971caa78a2..d3450219154 100644
--- a/static/openapi/registry.yaml
+++ b/static/openapi/registry.yaml
@@ -5503,6 +5503,11 @@ components:
           type:
             - string
             - "null"
+        runner_capability_version:
+          type:
+            - string
+            - "null"
+          description: Runner capability version recorded at execution time, separate from the AdCP version under test. Null when not recorded, including historical runs.
         overall_status:
           type: string
         headline: