diff --git a/tests/integration/trigger-config-resolver.test.ts b/tests/integration/trigger-config-resolver.test.ts
new file mode 100644
index 00000000..3ec30437
--- /dev/null
+++ b/tests/integration/trigger-config-resolver.test.ts
@@ -0,0 +1,488 @@
+/**
+ * Integration tests: Trigger Config Resolver
+ *
+ * Tests the full resolution chain for trigger configurations:
+ *   definition defaults → DB overrides → merged output
+ *
+ * Functions tested:
+ *   - isTriggerEnabled()
+ *   - getTriggerParameters()
+ *   - resolveTriggerConfigs()
+ *   - getResolvedTriggerConfig()
+ */
+
+import { beforeAll, beforeEach, describe, expect, it } from 'vitest';
+import { clearDefinitionCache } from '../../src/agents/definitions/loader.js';
+import type { AgentDefinition } from '../../src/agents/definitions/schema.js';
+import {
+	getResolvedTriggerConfig,
+	getTriggerParameters,
+	isTriggerEnabled,
+	resolveTriggerConfigs,
+} from '../../src/triggers/config-resolver.js';
+import { truncateAll } from './helpers/db.js';
+import {
+	seedAgentConfig,
+	seedAgentDefinition,
+	seedOrg,
+	seedProject,
+	seedTriggerConfig,
+} from './helpers/seed.js';
+
+// ============================================================================
+// Test fixtures
+// ============================================================================
+
+const PROJECT_ID = 'test-project';
+const AGENT_TYPE = 'test-resolver-agent';
+
+/** A definition with two triggers, one enabled and one disabled by default */
+const AGENT_DEFINITION_WITH_TRIGGERS: Partial<AgentDefinition> = {
+	triggers: [
+		{
+			event: 'pm:status-changed',
+			label: 'Status Changed',
+			description: 'Fires when a work item status changes',
+			defaultEnabled: true,
+			parameters: [
+				{
+					name: 'authorMode',
+					type: 'select',
+					label: 'Author Mode',
+					description: 'Which author PRs to review',
+					required: false,
+					defaultValue: 'own',
+					options: ['own', 'external'],
+				},
+			],
+		},
+		{
+			event: 'scm:check-suite-success',
+			label: 'CI Passed',
+			description: 'Fires when CI checks pass',
+			defaultEnabled: false,
+			parameters: [],
+		},
+	],
+};
+
+/** A definition with no triggers */
+const AGENT_DEFINITION_NO_TRIGGERS: Partial<AgentDefinition> = {
+	triggers: [],
+};
+
+// ============================================================================
+// Setup
+// ============================================================================
+
+beforeAll(async () => {
+	await truncateAll();
+});
+
+beforeEach(async () => {
+	await truncateAll();
+	clearDefinitionCache();
+	await seedOrg();
+	await seedProject();
+});
+
+// ============================================================================
+// isTriggerEnabled
+// ============================================================================
+
+describe('isTriggerEnabled()', () => {
+	it('returns definition default (true) when no DB override exists', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+
+		const enabled = await isTriggerEnabled(PROJECT_ID, AGENT_TYPE, 'pm:status-changed');
+		expect(enabled).toBe(true);
+	});
+
+	it('returns definition default (false) when no DB override exists', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+
+		const enabled = await isTriggerEnabled(PROJECT_ID, AGENT_TYPE, 'scm:check-suite-success');
+		expect(enabled).toBe(false);
+	});
+
+	it('returns DB override (false) when definition default is true', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+		await seedTriggerConfig({
+			projectId: PROJECT_ID,
+			agentType: AGENT_TYPE,
+			triggerEvent: 'pm:status-changed',
+			enabled: false,
+		});
+
+		const enabled = await isTriggerEnabled(PROJECT_ID, AGENT_TYPE, 'pm:status-changed');
+		expect(enabled).toBe(false);
+	});
+
+	it('returns DB override (true) when definition default is false', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+		await seedTriggerConfig({
+			projectId: PROJECT_ID,
+			agentType: AGENT_TYPE,
+			triggerEvent: 'scm:check-suite-success',
+			enabled: true,
+		});
+
+		const enabled = await isTriggerEnabled(PROJECT_ID, AGENT_TYPE, 'scm:check-suite-success');
+		expect(enabled).toBe(true);
+	});
+
+	it('returns false when agent is not enabled for project (no agent_config row)', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		// No seedAgentConfig() call — agent not enabled for this project
+
+		const enabled = await isTriggerEnabled(PROJECT_ID, AGENT_TYPE, 'pm:status-changed');
+		expect(enabled).toBe(false);
+	});
+
+	it('returns false for unknown agent type', async () => {
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+
+		const enabled = await isTriggerEnabled(PROJECT_ID, 'nonexistent-agent', 'pm:status-changed');
+		expect(enabled).toBe(false);
+	});
+
+	it('returns false for unknown trigger event on a known agent', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+
+		const enabled = await isTriggerEnabled(PROJECT_ID, AGENT_TYPE, 'pm:unknown-event');
+		expect(enabled).toBe(false);
+	});
+});
+
+// ============================================================================
+// getTriggerParameters
+// ============================================================================
+
+describe('getTriggerParameters()', () => {
+	it('returns definition default parameters when no DB override exists', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+
+		const params = await getTriggerParameters(PROJECT_ID, AGENT_TYPE, 'pm:status-changed');
+		expect(params).toEqual({ authorMode: 'own' });
+	});
+
+	it('returns empty object when trigger has no parameters', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+
+		const params = await getTriggerParameters(PROJECT_ID, AGENT_TYPE, 'scm:check-suite-success');
+		expect(params).toEqual({});
+	});
+
+	it('returns DB override parameters (DB wins over definition default)', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+		await seedTriggerConfig({
+			projectId: PROJECT_ID,
+			agentType: AGENT_TYPE,
+			triggerEvent: 'pm:status-changed',
+			enabled: true,
+			parameters: { authorMode: 'external' },
+		});
+
+		const params = await getTriggerParameters(PROJECT_ID, AGENT_TYPE, 'pm:status-changed');
+		expect(params).toEqual({ authorMode: 'external' });
+	});
+
+	it('merges definition defaults with DB overrides (DB wins on conflicts, both keys included)', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+		await seedTriggerConfig({
+			projectId: PROJECT_ID,
+			agentType: AGENT_TYPE,
+			triggerEvent: 'pm:status-changed',
+			enabled: true,
+			// DB adds a new key `threshold` while also overriding `authorMode`
+			parameters: { authorMode: 'external', threshold: 0.5 },
+		});
+
+		const params = await getTriggerParameters(PROJECT_ID, AGENT_TYPE, 'pm:status-changed');
+		// definition default `authorMode: 'own'` is overridden by DB `authorMode: 'external'`
+		// DB-only key `threshold: 0.5` is included in the merge
+		expect(params).toEqual({ authorMode: 'external', threshold: 0.5 });
+	});
+
+	it('returns empty object when agent is not enabled for project', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		// No seedAgentConfig() call
+
+		const params = await getTriggerParameters(PROJECT_ID, AGENT_TYPE, 'pm:status-changed');
+		expect(params).toEqual({});
+	});
+
+	it('returns empty object for unknown agent type', async () => {
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+
+		const params = await getTriggerParameters(PROJECT_ID, 'nonexistent-agent', 'pm:status-changed');
+		expect(params).toEqual({});
+	});
+
+	it('returns empty object for unknown trigger event', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+
+		const params = await getTriggerParameters(PROJECT_ID, AGENT_TYPE, 'pm:unknown-event');
+		expect(params).toEqual({});
+	});
+});
+
+// ============================================================================
+// resolveTriggerConfigs
+// ============================================================================
+
+describe('resolveTriggerConfigs()', () => {
+	it('returns all triggers with definition defaults when no DB overrides exist', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+
+		const configs = await resolveTriggerConfigs(PROJECT_ID, AGENT_TYPE);
+
+		expect(configs).toHaveLength(2);
+
+		const statusChangedConfig = configs.find((c) => c.event === 'pm:status-changed');
+		expect(statusChangedConfig).toBeDefined();
+		expect(statusChangedConfig?.enabled).toBe(true);
+		expect(statusChangedConfig?.parameters).toEqual({ authorMode: 'own' });
+		expect(statusChangedConfig?.isCustomized).toBe(false);
+		expect(statusChangedConfig?.label).toBe('Status Changed');
+
+		const ciConfig = configs.find((c) => c.event === 'scm:check-suite-success');
+		expect(ciConfig).toBeDefined();
+		expect(ciConfig?.enabled).toBe(false);
+		expect(ciConfig?.parameters).toEqual({});
+		expect(ciConfig?.isCustomized).toBe(false);
+	});
+
+	it('isCustomized is true when DB override exists', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+		await seedTriggerConfig({
+			projectId: PROJECT_ID,
+			agentType: AGENT_TYPE,
+			triggerEvent: 'pm:status-changed',
+			enabled: false,
+			parameters: { authorMode: 'external' },
+		});
+
+		const configs = await resolveTriggerConfigs(PROJECT_ID, AGENT_TYPE);
+
+		expect(configs).toHaveLength(2);
+
+		const statusChangedConfig = configs.find((c) => c.event === 'pm:status-changed');
+		expect(statusChangedConfig?.enabled).toBe(false);
+		expect(statusChangedConfig?.parameters).toEqual({ authorMode: 'external' });
+		expect(statusChangedConfig?.isCustomized).toBe(true);
+
+		// Non-overridden trigger should have isCustomized: false
+		const ciConfig = configs.find((c) => c.event === 'scm:check-suite-success');
+		expect(ciConfig?.isCustomized).toBe(false);
+	});
+
+	it('returns empty array when agent is not enabled for project', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		// No seedAgentConfig() call
+
+		const configs = await resolveTriggerConfigs(PROJECT_ID, AGENT_TYPE);
+		expect(configs).toEqual([]);
+	});
+
+	it('returns empty array for unknown agent type', async () => {
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+
+		const configs = await resolveTriggerConfigs(PROJECT_ID, 'nonexistent-agent');
+		expect(configs).toEqual([]);
+	});
+
+	it('returns empty array when definition has no triggers', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_NO_TRIGGERS,
+		});
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+
+		const configs = await resolveTriggerConfigs(PROJECT_ID, AGENT_TYPE);
+		expect(configs).toEqual([]);
+	});
+
+	it('merges DB overrides correctly across multiple triggers', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+		// Override both triggers
+		await seedTriggerConfig({
+			projectId: PROJECT_ID,
+			agentType: AGENT_TYPE,
+			triggerEvent: 'pm:status-changed',
+			enabled: false,
+			parameters: { authorMode: 'external', threshold: 0.5 },
+		});
+		await seedTriggerConfig({
+			projectId: PROJECT_ID,
+			agentType: AGENT_TYPE,
+			triggerEvent: 'scm:check-suite-success',
+			enabled: true,
+			parameters: {},
+		});
+
+		const configs = await resolveTriggerConfigs(PROJECT_ID, AGENT_TYPE);
+
+		expect(configs).toHaveLength(2);
+
+		const statusChangedConfig = configs.find((c) => c.event === 'pm:status-changed');
+		expect(statusChangedConfig?.enabled).toBe(false);
+		expect(statusChangedConfig?.parameters).toEqual({ authorMode: 'external', threshold: 0.5 });
+		expect(statusChangedConfig?.isCustomized).toBe(true);
+
+		const ciConfig = configs.find((c) => c.event === 'scm:check-suite-success');
+		expect(ciConfig?.enabled).toBe(true);
+		expect(ciConfig?.isCustomized).toBe(true);
+	});
+});
+
+// ============================================================================
+// getResolvedTriggerConfig
+// ============================================================================
+
+describe('getResolvedTriggerConfig()', () => {
+	it('returns resolved config for a known trigger event (no DB override)', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+
+		const config = await getResolvedTriggerConfig(PROJECT_ID, AGENT_TYPE, 'pm:status-changed');
+
+		expect(config).not.toBeNull();
+		expect(config?.event).toBe('pm:status-changed');
+		expect(config?.label).toBe('Status Changed');
+		expect(config?.enabled).toBe(true);
+		expect(config?.parameters).toEqual({ authorMode: 'own' });
+		expect(config?.isCustomized).toBe(false);
+	});
+
+	it('returns resolved config with DB overrides when present', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+		await seedTriggerConfig({
+			projectId: PROJECT_ID,
+			agentType: AGENT_TYPE,
+			triggerEvent: 'pm:status-changed',
+			enabled: false,
+			parameters: { authorMode: 'external' },
+		});
+
+		const config = await getResolvedTriggerConfig(PROJECT_ID, AGENT_TYPE, 'pm:status-changed');
+
+		expect(config).not.toBeNull();
+		expect(config?.enabled).toBe(false);
+		expect(config?.parameters).toEqual({ authorMode: 'external' });
+		expect(config?.isCustomized).toBe(true);
+	});
+
+	it('returns null for unknown trigger event', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+
+		const config = await getResolvedTriggerConfig(PROJECT_ID, AGENT_TYPE, 'pm:unknown-event');
+		expect(config).toBeNull();
+	});
+
+	it('returns null when agent is not enabled for project', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		// No seedAgentConfig() call
+
+		const config = await getResolvedTriggerConfig(PROJECT_ID, AGENT_TYPE, 'pm:status-changed');
+		expect(config).toBeNull();
+	});
+
+	it('returns null for unknown agent type', async () => {
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+
+		const config = await getResolvedTriggerConfig(
+			PROJECT_ID,
+			'nonexistent-agent',
+			'pm:status-changed',
+		);
+		expect(config).toBeNull();
+	});
+
+	it('includes description and providers from definition', async () => {
+		await seedAgentDefinition({
+			agentType: AGENT_TYPE,
+			definition: AGENT_DEFINITION_WITH_TRIGGERS,
+		});
+		await seedAgentConfig({ projectId: PROJECT_ID, agentType: AGENT_TYPE });
+
+		const config = await getResolvedTriggerConfig(PROJECT_ID, AGENT_TYPE, 'pm:status-changed');
+
+		expect(config?.description).toBe('Fires when a work item status changes');
+	});
+});