diff --git a/src/cli/commands/decision.ts b/src/cli/commands/decision.ts
index 66b693b..f3b162a 100644
--- a/src/cli/commands/decision.ts
+++ b/src/cli/commands/decision.ts
@@ -1,54 +1,22 @@
 import { input } from '@inquirer/prompts';
-import { join } from 'path';
-import { getEntityDir } from '../../core/paths.js';
-import { getNextId } from '../../core/counter.js';
-import { readEntity, writeEntity } from '../../core/files.js';
-import { DecisionSchema, type Decision } from '../../core/schema.js';
-import { Index } from '../../core/index.js';
+import { createDecision, listDecisions } from '../../core/services/decisionService.js';
+import type { Decision } from '../../core/schema.js';
 
 export async function decisionCreate(cwd: string, options: Partial<Decision> = {}): Promise<void> {
   const title = options.title ?? await input({ message: 'Decision title:' });
   const context = options.context ?? await input({ message: 'Context:' });
   const decision = options.decision ?? await input({ message: 'Decision:' });
 
-  const now = new Date().toISOString();
-  const record: Decision = DecisionSchema.parse({
-    id: getNextId(cwd, 'decision'),
-    title,
-    context,
-    decision,
-    createdAt: now,
-    updatedAt: now,
-  });
-
-  const filePath = join(getEntityDir(cwd, 'decisions'), `${record.id}.md`);
-  writeEntity(filePath, record, `# ${record.title}\n\n## Decision\n\n${record.decision}\n\n## Context\n\n${record.context}`);
-
-  const index = new Index(cwd);
-  index.upsert({
-    id: record.id,
-    type: 'decision',
-    title: record.title,
-    content: `${record.context} ${record.decision}`,
-    filePath,
-    createdAt: record.createdAt,
-    updatedAt: record.updatedAt,
-  });
-  index.close();
-
+  const record = createDecision(cwd, { title, context, decision });
   console.log(`Decision recorded: ${record.id}`);
 }
 
 export function decisionList(cwd: string): void {
-  const index = new Index(cwd);
-  const decisions = index.list('decision');
-  index.close();
-
+  const decisions = listDecisions(cwd);
   if (decisions.length === 0) {
     console.log('No decisions found.');
     return;
   }
-
   for (const d of decisions) {
     console.log(`${d.id}: ${d.title}`);
   }
diff --git a/src/core/services/decisionService.ts b/src/core/services/decisionService.ts
new file mode 100644
index 0000000..fb6cf7b
--- /dev/null
+++ b/src/core/services/decisionService.ts
@@ -0,0 +1,52 @@
+import { join } from 'path';
+import { getEntityDir } from '../paths.js';
+import { getNextId } from '../counter.js';
+import { readEntity, writeEntity } from '../files.js';
+import { DecisionSchema, type Decision } from '../schema.js';
+import { Index } from '../index.js';
+
+export function createDecision(cwd: string, options: Partial<Decision> = {}): Decision {
+  const now = new Date().toISOString();
+  const record: Decision = DecisionSchema.parse({
+    id: getNextId(cwd, 'decision'),
+    title: options.title ?? 'Decision',
+    context: options.context ?? '',
+    decision: options.decision ?? '',
+    status: options.status ?? 'accepted',
+    consequences: options.consequences ?? [],
+    alternatives: options.alternatives ?? [],
+    relatedDecisions: options.relatedDecisions ?? [],
+    createdAt: now,
+    updatedAt: now,
+  });
+
+  const filePath = join(getEntityDir(cwd, 'decisions'), `${record.id}.md`);
+  writeEntity(filePath, record, `# ${record.title}\n\n## Decision\n\n${record.decision}\n\n## Context\n\n${record.context}`);
+
+  const index = new Index(cwd);
+  index.upsert({
+    id: record.id,
+    type: 'decision',
+    title: record.title,
+    content: `${record.context} ${record.decision}`,
+    filePath,
+    createdAt: record.createdAt,
+    updatedAt: record.updatedAt,
+  });
+  index.close();
+
+  return record;
+}
+
+export function listDecisions(cwd: string): ReturnType<Index['list']> {
+  const index = new Index(cwd);
+  const decisions = index.list('decision');
+  index.close();
+  return decisions;
+}
+
+export function getDecision(cwd: string, id: string): { decision: Decision; body: string; filePath: string } {
+  const filePath = join(getEntityDir(cwd, 'decisions'), `${id}.md`);
+  const { frontmatter, body } = readEntity(filePath);
+  return { decision: DecisionSchema.parse(frontmatter), body, filePath };
+}
diff --git a/tests/decisionService.test.ts b/tests/decisionService.test.ts
new file mode 100644
index 0000000..8980a4e
--- /dev/null
+++ b/tests/decisionService.test.ts
@@ -0,0 +1,19 @@
+import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { mkdtempSync, rmSync } from 'fs';
+import { tmpdir } from 'os';
+import { join } from 'path';
+import { createDecision, listDecisions, getDecision } from '../src/core/services/decisionService.js';
+
+describe('decisionService', () => {
+  let cwd: string;
+
+  beforeEach(() => { cwd = mkdtempSync(join(tmpdir(), 'ah-dec-')); });
+  afterEach(() => { rmSync(cwd, { recursive: true, force: true }); });
+
+  it('creates and reads a decision', () => {
+    const d = createDecision(cwd, { title: 'Use SQLite', context: 'c', decision: 'd' });
+    expect(d.id).toBe('DEC-0001');
+    expect(getDecision(cwd, d.id).decision.title).toBe('Use SQLite');
+    expect(listDecisions(cwd)).toHaveLength(1);
+  });
+});