diff --git a/packages/obsidian/src/library/book.ts b/packages/obsidian/src/library/book.ts
new file mode 100644
index 0000000..77f4c9d
--- /dev/null
+++ b/packages/obsidian/src/library/book.ts
@@ -0,0 +1,187 @@
+import type { LibraryNoteCtx, MediaTypeSpec, SpecDeps } from 'packages/obsidian/src/library/types';
+import { stripQuotes, extractMyNotes, extractCustomSections, type CustomSection } from 'packages/obsidian/src/watchlist/parse';
+import { yamlList, yamlScalar, quotedOrNull } from 'packages/obsidian/src/watchlist/yaml';
+
+const OPENLIBRARY_BASE = 'https://openlibrary.org';
+
+export interface BookRecord {
+	title: string;
+	readStatus: string;
+	rating: string;
+	ratingStars: string;
+	authors: string[];
+	year: number | null;
+	pages: number | null;
+	genre: string[];
+	olid: string;
+	isbn: string;
+	poster: string | null;
+	url: string;
+}
+
+function deriveReadStatus(prev: Record<string, string>): string {
+	const canonical = stripQuotes(prev['read_status']);
+	if (canonical) return canonical;
+	// skeleton conversion: legacy boolean `read` field
+	return stripQuotes(prev['read']) === 'true' ? 'Read' : 'Unread';
+}
+
+function deriveRating(prev: Record<string, string>): { rating: string; ratingStars: string } {
+	const canonicalRating = stripQuotes(prev['rating']);
+	if (canonicalRating) return { rating: canonicalRating, ratingStars: stripQuotes(prev['rating_stars']) };
+	// skeleton conversion: legacy numeric `personalRating` field -> N stars
+	const legacy = Number(stripQuotes(prev['personalRating']));
+	if (Number.isFinite(legacy) && legacy > 0) {
+		return { rating: String(legacy), ratingStars: '⭐️'.repeat(legacy) };
+	}
+	return { rating: '0', ratingStars: '' };
+}
+
+function deriveAuthors(doc: any, prev: Record<string, string>): string[] {
+	const fresh: string[] = Array.isArray(doc.author_name) ? doc.author_name.filter(Boolean) : [];
+	if (fresh.length) return fresh;
+	// skeleton conversion: legacy singular `author` field, used only when Open Library gives none
+	const legacy = stripQuotes(prev['author']);
+	return legacy ? [legacy] : [];
+}
+
+/**
+ * Pure mapper: Open Library `search.json` doc + prev frontmatter -> canonical BookRecord.
+ * User-managed fields (read_status, rating, rating_stars, isbn) are preserved from prev
+ * (with legacy-skeleton fallback for read_status/rating/authors); everything else is
+ * freshly derived from the doc on every call.
+ */
+export function buildBook(doc: any, prev: Record<string, string>): BookRecord {
+	const title: string = doc.title ?? stripQuotes(prev['title']) ?? '';
+	const { rating, ratingStars } = deriveRating(prev);
+	const readStatus = deriveReadStatus(prev);
+	const authors = deriveAuthors(doc, prev);
+	const genre: string[] = Array.isArray(doc.subject) ? doc.subject.filter(Boolean).slice(0, 8) : [];
+	const olid = String(doc.key ?? '').replace(/^\/works\//, '') || stripQuotes(prev['olid']);
+
+	return {
+		title,
+		readStatus,
+		rating,
+		ratingStars,
+		authors,
+		year: typeof doc.first_publish_year === 'number' ? doc.first_publish_year : null,
+		pages: typeof doc.number_of_pages_median === 'number' ? doc.number_of_pages_median : null,
+		genre,
+		olid,
+		isbn: stripQuotes(prev['isbn']),
+		poster: doc.cover_i ? `https://covers.openlibrary.org/b/id/${doc.cover_i}-L.jpg` : null,
+		url: doc.key ? `${OPENLIBRARY_BASE}${doc.key}` : olid ? `${OPENLIBRARY_BASE}/works/${olid}` : '',
+	};
+}
+
+/** Carries the legacy goodreads search link forward as a `## Links` entry across every re-render. */
+function resolveGoodreadsLink(prev: Record<string, string>, body: string): string {
+	const fromBody = /\[Goodreads\]\(([^)]+)\)/.exec(body ?? '');
+	if (fromBody) return fromBody[1];
+	// first-pass skeleton conversion: legacy plain `url` field IS the goodreads link, before
+	// it gets overwritten by the canonical Open Library url
+	const legacyUrl = stripQuotes(prev['url']);
+	if (legacyUrl && !legacyUrl.includes('openlibrary.org')) return legacyUrl;
+	return '';
+}
+
+export function renderBook(r: BookRecord, myNotes: string, customSections: CustomSection[] = [], goodreadsUrl = ''): string {
+	const fm = [
+		'---',
+		'type: book_item',
+		`title: ${yamlScalar(r.title)}`,
+		`read_status: ${r.readStatus}`,
+		`rating: ${r.rating}`,
+		`rating_stars: ${r.ratingStars}`,
+		`authors: ${yamlList(r.authors)}`,
+		`year: ${r.year ?? 'null'}`,
+		`pages: ${r.pages ?? 'null'}`,
+		`genre: ${yamlList(r.genre)}`,
+		`olid: ${r.olid}`,
+		`isbn: ${r.isbn}`,
+		`poster: ${quotedOrNull(r.poster)}`,
+		`url: ${quotedOrNull(r.url)}`,
+		'tags: [books, book]',
+		'---',
+	];
+
+	const b: string[] = ['', `# ${r.title}`, ''];
+	if (r.poster) b.push(`![poster|200](${r.poster})`, '');
+	const meta = ['**Book**', ...[r.year !== null ? String(r.year) : '', r.pages !== null ? `${r.pages} p.` : ''].filter(x => x)];
+	b.push(meta.join(' · '), '');
+	b.push(`**Read Status:** ${r.readStatus}`, '');
+	if (r.authors.length) b.push(`**Authors:** ${r.authors.join(', ')}`, '');
+	const links: string[] = [];
+	if (r.url) links.push(`- [Open Library](${r.url})`);
+	if (goodreadsUrl) links.push(`- [Goodreads](${goodreadsUrl})`);
+	if (links.length) b.push('## Links', ...links, '');
+	for (const s of customSections) b.push(`## ${s.heading}`, s.content, '');
+	b.push('## My Notes', '', myNotes);
+	if (myNotes) b.push('');
+	return fm.join('\n') + '\n' + b.join('\n');
+}
+
+async function fetchDocs(query: string, deps: SpecDeps): Promise<any[]> {
+	const qs = new URLSearchParams({ q: query, limit: '10' });
+	const res = await deps.http(`${OPENLIBRARY_BASE}/search.json?${qs.toString()}`, {});
+	return res?.docs ?? [];
+}
+
+export const bookSpec: MediaTypeSpec = {
+	typeName: 'book',
+	itemType: 'book_item',
+	folderSettingKey: 'libraryBookFolder',
+	enabledSettingKey: 'libraryBookEnabled',
+	throttleMs: 250,
+
+	hasId(fm: Record<string, string>): boolean {
+		return !!stripQuotes(fm['olid']);
+	},
+
+	isActive(fm: Record<string, string>): boolean {
+		// static once enriched; no chapter/issue sources, no flips -- only a missing
+		// olid ever makes a book note active again (a full sync bypasses this check)
+		return !stripQuotes(fm['olid']);
+	},
+
+	async resolve(ctx: LibraryNoteCtx, deps: SpecDeps): Promise<Record<string, string> | null> {
+		const query = stripQuotes(ctx.frontmatter['title']) || ctx.filename.replace(/\.md$/, '');
+		if (!query) return null;
+		try {
+			const docs = await fetchDocs(query, deps);
+			if (docs.length === 0) return null;
+			const q = query.toLowerCase();
+			const exacts = docs.filter(d => String(d.title ?? '').toLowerCase() === q);
+			const pick = exacts.length === 1 ? exacts[0] : exacts.length === 0 && docs.length === 1 ? docs[0] : null;
+			if (!pick) return null;
+			const olid = String(pick.key ?? '').replace(/^\/works\//, '');
+			return olid ? { olid } : null;
+		} catch (e) {
+			deps.log(`book resolve failed for "${query}": ${String(e)}`);
+			return null;
+		}
+	},
+
+	async sync(ctx: LibraryNoteCtx, deps: SpecDeps): Promise<{ content: string; flipped: boolean } | null> {
+		const fm = ctx.frontmatter;
+		const olid = stripQuotes(fm['olid']);
+		if (!olid) return null; // needs resolve() first
+
+		const query = stripQuotes(fm['title']) || ctx.filename.replace(/\.md$/, '');
+		let docs: any[];
+		try {
+			docs = await fetchDocs(query, deps);
+		} catch (e) {
+			deps.log(`book open library fetch failed (olid ${olid}): ${String(e)}`);
+			return null;
+		}
+		const doc = docs.find(d => String(d.key ?? '') === `/works/${olid}`) ?? docs[0];
+		if (!doc) return null;
+
+		const record = buildBook(doc, fm);
+		const goodreadsUrl = resolveGoodreadsLink(fm, ctx.body);
+		const content = renderBook(record, extractMyNotes(ctx.body), extractCustomSections(ctx.body), goodreadsUrl);
+		return { content, flipped: false }; // static spec -- no automation, never flips
+	},
+};
diff --git a/tests/fixtures/canonical-book.md b/tests/fixtures/canonical-book.md
new file mode 100644
index 0000000..f2b1f5f
--- /dev/null
+++ b/tests/fixtures/canonical-book.md
@@ -0,0 +1,33 @@
+---
+type: book_item
+title: 1984
+read_status: Read
+rating: 5
+rating_stars: ⭐️⭐️⭐️⭐️⭐️
+authors: [George Orwell]
+year: 1949
+pages: 328
+genre: [Dystopian fiction, Science fiction, Politics, Totalitarianism, Fiction, Classic literature, "Government, resistance to", Surveillance]
+olid: OL1168083W
+isbn: 9780451524935
+poster: "https://covers.openlibrary.org/b/id/12919016-L.jpg"
+url: "https://openlibrary.org/works/OL1168083W"
+tags: [books, book]
+---
+
+# 1984
+
+![poster|200](https://covers.openlibrary.org/b/id/12919016-L.jpg)
+
+**Book** · 1949 · 328 p.
+
+**Read Status:** Read
+
+**Authors:** George Orwell
+
+## Links
+- [Open Library](https://openlibrary.org/works/OL1168083W)
+- [Goodreads](https://www.goodreads.com/search?q=1984)
+
+## My Notes
+
diff --git a/tests/fixtures/openlibrary-search.json b/tests/fixtures/openlibrary-search.json
new file mode 100644
index 0000000..9a0ad5a
--- /dev/null
+++ b/tests/fixtures/openlibrary-search.json
@@ -0,0 +1,30 @@
+{
+	"numFound": 1,
+	"start": 0,
+	"docs": [
+		{
+			"key": "/works/OL1168083W",
+			"title": "1984",
+			"author_name": ["George Orwell"],
+			"first_publish_year": 1949,
+			"number_of_pages_median": 328,
+			"subject": [
+				"Dystopian fiction",
+				"Science fiction",
+				"Politics",
+				"Totalitarianism",
+				"Fiction",
+				"Classic literature",
+				"Government, resistance to",
+				"Surveillance",
+				"Censorship",
+				"Propaganda",
+				"Big Brother (Fictitious character)",
+				"Thought control",
+				"Newspeak (Fictitious language)",
+				"Ministry of Truth (Fictitious organization)"
+			],
+			"cover_i": 12919016
+		}
+	]
+}
diff --git a/tests/library-book.test.ts b/tests/library-book.test.ts
new file mode 100644
index 0000000..7c63cb3
--- /dev/null
+++ b/tests/library-book.test.ts
@@ -0,0 +1,321 @@
+import { describe, expect, test } from 'bun:test';
+import { readFileSync } from 'node:fs';
+import { join } from 'node:path';
+import { buildBook, renderBook, bookSpec, type BookRecord } from 'packages/obsidian/src/library/book';
+import type { SpecDeps, LibraryNoteCtx } from 'packages/obsidian/src/library/types';
+import olFixture from 'tests/fixtures/openlibrary-search.json';
+
+const OL_DOC = olFixture.docs[0];
+
+const EMPTY_PREV: Record<string, string> = {};
+
+function makeDeps(overrides: Partial<SpecDeps> = {}): SpecDeps & { notifyCalls: string[]; logCalls: string[] } {
+	const notifyCalls: string[] = [];
+	const logCalls: string[] = [];
+	return {
+		http: async () => ({}),
+		httpText: async () => '',
+		getKey: () => '',
+		log: (msg: string) => {
+			logCalls.push(msg);
+		},
+		notify: (msg: string) => {
+			notifyCalls.push(msg);
+		},
+		notifyCalls,
+		logCalls,
+		...overrides,
+	};
+}
+
+describe('buildBook field mapping', () => {
+	const r = buildBook(OL_DOC, EMPTY_PREV);
+	test('core fields', () => {
+		expect(r.title).toBe('1984');
+		expect(r.olid).toBe('OL1168083W');
+		expect(r.authors).toEqual(['George Orwell']);
+		expect(r.year).toBe(1949);
+		expect(r.pages).toBe(328);
+		expect(r.poster).toBe('https://covers.openlibrary.org/b/id/12919016-L.jpg');
+		expect(r.url).toBe('https://openlibrary.org/works/OL1168083W');
+	});
+	test('genre capped at 8 (fixture has 14 subjects)', () => {
+		expect(r.genre.length).toBe(8);
+		expect(r.genre).toEqual([
+			'Dystopian fiction',
+			'Science fiction',
+			'Politics',
+			'Totalitarianism',
+			'Fiction',
+			'Classic literature',
+			'Government, resistance to',
+			'Surveillance',
+		]);
+	});
+	test('no cover_i -> poster null', () => {
+		expect(buildBook({ ...OL_DOC, cover_i: undefined }, EMPTY_PREV).poster).toBeNull();
+	});
+	test('no first_publish_year/number_of_pages_median -> year/pages null', () => {
+		const r2 = buildBook({ ...OL_DOC, first_publish_year: undefined, number_of_pages_median: undefined }, EMPTY_PREV);
+		expect(r2.year).toBeNull();
+		expect(r2.pages).toBeNull();
+	});
+});
+
+describe('buildBook user-field preservation', () => {
+	test('read_status defaults to Unread', () => {
+		expect(buildBook(OL_DOC, EMPTY_PREV).readStatus).toBe('Unread');
+	});
+	test('read_status carried from prev', () => {
+		expect(buildBook(OL_DOC, { read_status: 'Read' }).readStatus).toBe('Read');
+	});
+	test('rating/rating_stars carried from prev', () => {
+		const prev = { rating: '5', rating_stars: '⭐️⭐️⭐️⭐️⭐️' };
+		const r = buildBook(OL_DOC, prev);
+		expect(r.rating).toBe('5');
+		expect(r.ratingStars).toBe('⭐️⭐️⭐️⭐️⭐️');
+	});
+	test('isbn preserved when prev had it', () => {
+		expect(buildBook(OL_DOC, { isbn: '9780451524935' }).isbn).toBe('9780451524935');
+	});
+	test('isbn empty when prev had none', () => {
+		expect(buildBook(OL_DOC, EMPTY_PREV).isbn).toBe('');
+	});
+	test('authors always fresh from doc.author_name, ignoring any prior authors', () => {
+		expect(buildBook(OL_DOC, { authors: '[Someone Else]' }).authors).toEqual(['George Orwell']);
+	});
+});
+
+describe('buildBook skeleton conversion', () => {
+	test('read: true -> read_status Read', () => {
+		expect(buildBook(OL_DOC, { read: 'true', personalRating: '' }).readStatus).toBe('Read');
+	});
+	test('read: false -> read_status Unread', () => {
+		expect(buildBook(OL_DOC, { read: 'false', personalRating: '' }).readStatus).toBe('Unread');
+	});
+	test('personalRating 3 -> rating 3 + 3 stars', () => {
+		const r = buildBook(OL_DOC, { read: 'false', personalRating: '3' });
+		expect(r.rating).toBe('3');
+		expect(r.ratingStars).toBe('⭐️⭐️⭐️');
+	});
+	test('empty personalRating -> rating 0, no stars', () => {
+		const r = buildBook(OL_DOC, { read: 'false', personalRating: '' });
+		expect(r.rating).toBe('0');
+		expect(r.ratingStars).toBe('');
+	});
+	test('legacy `author` used only when doc has no author_name', () => {
+		const r = buildBook({ ...OL_DOC, author_name: undefined }, { author: 'George Orwell' });
+		expect(r.authors).toEqual(['George Orwell']);
+	});
+	test('no doc author_name and no legacy author -> empty authors', () => {
+		const r = buildBook({ ...OL_DOC, author_name: undefined }, EMPTY_PREV);
+		expect(r.authors).toEqual([]);
+	});
+});
+
+describe('renderBook golden', () => {
+	const RECORD: BookRecord = {
+		title: '1984',
+		readStatus: 'Read',
+		rating: '5',
+		ratingStars: '⭐️⭐️⭐️⭐️⭐️',
+		authors: ['George Orwell'],
+		year: 1949,
+		pages: 328,
+		genre: ['Dystopian fiction', 'Science fiction', 'Politics', 'Totalitarianism', 'Fiction', 'Classic literature', 'Government, resistance to', 'Surveillance'],
+		olid: 'OL1168083W',
+		isbn: '9780451524935',
+		poster: 'https://covers.openlibrary.org/b/id/12919016-L.jpg',
+		url: 'https://openlibrary.org/works/OL1168083W',
+	};
+
+	test('matches canonical book fixture byte-for-byte', () => {
+		const expected = readFileSync(join(import.meta.dir, 'fixtures', 'canonical-book.md'), 'utf-8');
+		expect(renderBook(RECORD, '', [], 'https://www.goodreads.com/search?q=1984')).toBe(expected);
+	});
+
+	test('custom section (Collection) placed after Links, before My Notes', () => {
+		const out = renderBook(RECORD, '', [{ heading: 'Collection', content: 'Part of [[Books]]' }], 'https://www.goodreads.com/search?q=1984');
+		const linksIdx = out.indexOf('## Links');
+		const collectionIdx = out.indexOf('## Collection');
+		const myNotesIdx = out.indexOf('## My Notes');
+		expect(collectionIdx).toBeGreaterThan(linksIdx);
+		expect(myNotesIdx).toBeGreaterThan(collectionIdx);
+		expect(out).toContain('## Collection\nPart of [[Books]]\n');
+	});
+
+	test('My Notes content preserved', () => {
+		const out = renderBook(RECORD, 'reread every few years');
+		expect(out).toContain('## My Notes\n\nreread every few years');
+	});
+
+	test('no goodreads url -> Links has only Open Library entry', () => {
+		const out = renderBook(RECORD, '');
+		expect(out).toContain('- [Open Library](https://openlibrary.org/works/OL1168083W)');
+		expect(out).not.toContain('[Goodreads]');
+	});
+
+	test('no poster -> poster line omitted', () => {
+		const r = { ...RECORD, poster: null };
+		expect(renderBook(r, '')).not.toContain('![poster');
+	});
+
+	test('no authors -> Authors line omitted', () => {
+		const r = { ...RECORD, authors: [] };
+		expect(renderBook(r, '')).not.toContain('**Authors:**');
+	});
+});
+
+describe('bookSpec.hasId', () => {
+	test('olid set -> true', () => expect(bookSpec.hasId({ olid: 'OL1168083W' })).toBe(true));
+	test('olid empty -> false', () => expect(bookSpec.hasId({ olid: '' })).toBe(false));
+	test('olid missing -> false', () => expect(bookSpec.hasId({})).toBe(false));
+});
+
+describe('bookSpec.isActive', () => {
+	test('olid empty -> active (needs first pass)', () => {
+		expect(bookSpec.isActive({})).toBe(true);
+	});
+	test('olid set -> static, regardless of read_status', () => {
+		expect(bookSpec.isActive({ olid: 'OL1168083W', read_status: 'Reading' })).toBe(false);
+	});
+	test('olid set + Read -> static', () => {
+		expect(bookSpec.isActive({ olid: 'OL1168083W', read_status: 'Read' })).toBe(false);
+	});
+	test('olid set + Unread -> static', () => {
+		expect(bookSpec.isActive({ olid: 'OL1168083W', read_status: 'Unread' })).toBe(false);
+	});
+});
+
+function ctxFor(fm: Record<string, string>, body = '## My Notes\n\n'): LibraryNoteCtx {
+	return { frontmatter: fm, body, filename: '1984.md' };
+}
+
+describe('bookSpec.sync — open library enrich', () => {
+	test('no olid -> null (needs resolve first)', async () => {
+		const deps = makeDeps();
+		const result = await bookSpec.sync(ctxFor({}), deps);
+		expect(result).toBeNull();
+	});
+
+	test('open library fetch failure -> log, return null (no throw)', async () => {
+		const deps = makeDeps({
+			http: async () => {
+				throw new Error('network down');
+			},
+		});
+		const result = await bookSpec.sync(ctxFor({ olid: 'OL1168083W', title: '1984' }), deps);
+		expect(result).toBeNull();
+		expect(deps.logCalls.length).toBeGreaterThan(0);
+	});
+
+	test('doc not found for olid, no results at all -> null', async () => {
+		const deps = makeDeps({ http: async () => ({ docs: [] }) });
+		const result = await bookSpec.sync(ctxFor({ olid: 'OL1168083W', title: '1984' }), deps);
+		expect(result).toBeNull();
+	});
+
+	test('successful enrich -> canonical fm + flipped always false', async () => {
+		const deps = makeDeps({ http: async () => olFixture });
+		const fm = { olid: 'OL1168083W', title: '1984', read_status: 'Read', rating: '5', rating_stars: '⭐️⭐️⭐️⭐️⭐️' };
+		const result = await bookSpec.sync(ctxFor(fm), deps);
+		expect(result).not.toBeNull();
+		expect(result!.flipped).toBe(false);
+		expect(result!.content).toContain('type: book_item');
+		expect(result!.content).toContain('olid: OL1168083W');
+		expect(result!.content).toContain('authors: [George Orwell]');
+		expect(result!.content).toContain('year: 1949');
+		expect(result!.content).toContain('pages: 328');
+	});
+
+	test('isbn preserved through sync when prev had it', async () => {
+		const deps = makeDeps({ http: async () => olFixture });
+		const fm = { olid: 'OL1168083W', title: '1984', isbn: '9780451524935' };
+		const result = await bookSpec.sync(ctxFor(fm), deps);
+		expect(result!.content).toContain('isbn: 9780451524935');
+	});
+
+	test('first-pass skeleton conversion: legacy author/read/personalRating/goodreads url -> canonical + Links entry, Collection section preserved', async () => {
+		const deps = makeDeps({ http: async () => olFixture });
+		const fm = {
+			olid: 'OL1168083W',
+			title: '1984',
+			author: 'George Orwell',
+			read: 'false',
+			personalRating: '',
+			url: 'https://www.goodreads.com/search?q=1984',
+		};
+		const body = '## Collection\n\nPart of [[Books]]\n\n## My Notes\n\n';
+		const result = await bookSpec.sync(ctxFor(fm, body), deps);
+		expect(result!.content).toContain('read_status: Unread');
+		expect(result!.content).toContain('authors: [George Orwell]');
+		expect(result!.content).toContain('- [Open Library](https://openlibrary.org/works/OL1168083W)');
+		expect(result!.content).toContain('- [Goodreads](https://www.goodreads.com/search?q=1984)');
+		expect(result!.content).toContain('## Collection\n\nPart of [[Books]]\n');
+	});
+
+	test('goodreads link carried forward from already-converted body, ignoring canonical fm url', async () => {
+		const deps = makeDeps({ http: async () => olFixture });
+		const fm = { olid: 'OL1168083W', title: '1984', url: 'https://openlibrary.org/works/OL1168083W' };
+		const body = '## Links\n- [Open Library](https://openlibrary.org/works/OL1168083W)\n- [Goodreads](https://www.goodreads.com/search?q=1984)\n\n## My Notes\n\n';
+		const result = await bookSpec.sync(ctxFor(fm, body), deps);
+		expect(result!.content).toContain('- [Goodreads](https://www.goodreads.com/search?q=1984)');
+	});
+
+	test('no goodreads link anywhere -> Links has only Open Library entry', async () => {
+		const deps = makeDeps({ http: async () => olFixture });
+		const fm = { olid: 'OL1168083W', title: '1984' };
+		const result = await bookSpec.sync(ctxFor(fm), deps);
+		expect(result!.content).toContain('- [Open Library](https://openlibrary.org/works/OL1168083W)');
+		expect(result!.content).not.toContain('[Goodreads]');
+	});
+
+	test('My Notes content preserved through sync', async () => {
+		const deps = makeDeps({ http: async () => olFixture });
+		const fm = { olid: 'OL1168083W', title: '1984' };
+		const result = await bookSpec.sync(ctxFor(fm, '## My Notes\n\nreread every few years'), deps);
+		expect(result!.content).toContain('## My Notes\n\nreread every few years');
+	});
+});
+
+describe('bookSpec.resolve', () => {
+	test('unique exact title match -> accepted', async () => {
+		const deps = makeDeps({ http: async () => olFixture });
+		const result = await bookSpec.resolve(ctxFor({ title: '1984' }, ''), deps);
+		expect(result).toEqual({ olid: 'OL1168083W' });
+	});
+	test('no exact match, sole result -> accepted', async () => {
+		const deps = makeDeps({
+			http: async () => ({ docs: [{ key: '/works/OL999W', title: 'Some Other Title' }] }),
+		});
+		const result = await bookSpec.resolve(ctxFor({ title: '1984' }, ''), deps);
+		expect(result).toEqual({ olid: 'OL999W' });
+	});
+	test('ambiguous (multiple results, no exact match) -> null', async () => {
+		const deps = makeDeps({
+			http: async () => ({
+				docs: [
+					{ key: '/works/OL1W', title: 'Foo' },
+					{ key: '/works/OL2W', title: 'Bar' },
+				],
+			}),
+		});
+		const result = await bookSpec.resolve(ctxFor({ title: '1984' }, ''), deps);
+		expect(result).toBeNull();
+	});
+	test('no results -> null', async () => {
+		const deps = makeDeps({ http: async () => ({ docs: [] }) });
+		const result = await bookSpec.resolve(ctxFor({ title: '1984' }, ''), deps);
+		expect(result).toBeNull();
+	});
+	test('http throws -> log, return null (no throw)', async () => {
+		const deps = makeDeps({
+			http: async () => {
+				throw new Error('down');
+			},
+		});
+		const result = await bookSpec.resolve(ctxFor({ title: '1984' }, ''), deps);
+		expect(result).toBeNull();
+		expect(deps.logCalls.length).toBeGreaterThan(0);
+	});
+});