diff --git a/crates/utopia-server/src/api/auth_routes.rs b/crates/utopia-server/src/api/auth_routes.rs
index a9a532d46..464a99120 100644
--- a/crates/utopia-server/src/api/auth_routes.rs
+++ b/crates/utopia-server/src/api/auth_routes.rs
@@ -7,7 +7,6 @@ use serde_json::json;
 use utopia_core::models::User;
 use utopia_core::AppError;
 
-use super::kbs::{install_packs, DEFAULT_PACK};
 use crate::auth::{self, AuthUser};
 use crate::error::ApiResult;
 use crate::state::AppState;
@@ -66,7 +65,7 @@ pub async fn register(
     let utopia_store::accounts::Registered {
         user,
         workspace,
-        general_kb,
+        general_kb: _,
     } = utopia_store::accounts::register(
         &state.pool,
         req.email.trim(),
@@ -77,23 +76,11 @@ pub async fn register(
     )
     .await?;
 
-    /* 首个用户那个 General 库也要有词汇表（#322）。
-    建库对话框里 schema.org 是预勾选的默认（0008、0009），而这条路径绕过了
-    对话框——于是每个部署的第一个库、也就是新用户落地的那个，本体是空的：
-    没有 domain/range，抽取的方向就定不住，事实退化成 related_to，
-    而这正是 0008 装包要解决的事。
-
-    **装不上不能挡住注册。** 事务已经提交，账号已经存在；这一步失败只是
-    回到今天的行为（库空着，日后手动装包再重跑类型消解即可，见 0009），
-    让人注册不进来则是把小事变成大事 */
-    if let Some(kb_id) = general_kb {
-        if install_packs(&state, kb_id, user.id, &[DEFAULT_PACK.to_string()])
-            .await
-            .is_err()
-        {
-            tracing::warn!(kb_id = %kb_id, pack = DEFAULT_PACK, "默认库的冷启动本体包没装上");
-        }
-    }
+    // 首个用户那个 General 库**空着起步**（#580）。从前这里给它装 schema.org（#322），
+    // 理由是没有 domain/range 事实就没方向；量过之后（#580 的对照）：包给的是实体
+    // 类型，不是谓词——装了包八成事实照样没谓词；空库靠 bootstrap 从文档里长出
+    // 十几个类、上百条关系，都是语料自己的说法，每块的提示词从 18k tokens 回到 2k。
+    // 包还在建库对话框里，要的人一键装
 
     let token = auth::issue_token(&state, user.id)?;
     let secure = auth::behind_tls(&headers, state.cookie_secure);
diff --git a/crates/utopia-server/src/api/kbs.rs b/crates/utopia-server/src/api/kbs.rs
index 95d2ad077..89a4a71d5 100644
--- a/crates/utopia-server/src/api/kbs.rs
+++ b/crates/utopia-server/src/api/kbs.rs
@@ -391,10 +391,9 @@ pub async fn audit_log(
 /// **一个包失败不回滚已装的**：本体是加法，装了一半的库仍然可用，
 /// 而回滚要撤已经建好的类——那正是 0008 决定不做导入撤销的理由。
 /// 失败信息里带上是哪个包，让人知道从哪补。
-/// 建库对话框里预勾选的那个包（0008、0009）。注册时建出来的 General 库
-/// 绕过了对话框，所以它在那条路径上也要用同一个默认（#322）。
-pub(super) const DEFAULT_PACK: &str = "schema-org";
-
+///
+/// 没有默认包（#580）：注册建的 General 库与对话框里新建的库都空着起步，
+/// 装哪个包是建库的人选的。
 pub(super) async fn install_packs(
     state: &AppState,
     kb_id: Uuid,
diff --git a/docs/decisions/0008-ontology-packs-as-cold-start.md b/docs/decisions/0008-ontology-packs-as-cold-start.md
index 53216bd55..9b56d3bc6 100644
--- a/docs/decisions/0008-ontology-packs-as-cold-start.md
+++ b/docs/decisions/0008-ontology-packs-as-cold-start.md
@@ -1,9 +1,10 @@
 # 0008 · Ontology packs as the cold start
 
 - **Status**: Built · five packs embedded in the binary (gzip, 1.7 MB → 316 KB),
-  multi-select at KB creation with schema.org checked by default, 22-row static alignment
-  table · a new KB seeds no relations: the packs are the whole ontology · the three open
-  questions stay open; the Chinese-label one got worse (2026-09-02 check)
+  multi-select at KB creation, 22-row static alignment table · a new KB seeds no
+  relations: the packs are the whole ontology · **no pack is checked by default and the
+  base made at registration installs none** (2026-09-10, #580) · the three open questions
+  stay open; the Chinese-label one got worse (2026-09-02 check)
 - **Written**: 2026-08-30 · condensed into English 2026-09-03
 - **Related**: [0001](0001-ontology-import-and-governance.md) criteria and IRI/key split;
   [0006](0006-ontology-scale-and-the-prompt.md) prompt budget;
@@ -99,6 +100,21 @@ order status).
   of packs is not prompt length but **choice**: many names are generic with narrow meanings
   (`affectedBy` is a medical test, `competitor` a sports event), and picking by name or
   vector will hit them.
+- 2026-09-10 (#580): **the default is no pack.** schema.org was pre-selected in the creation
+  dialog and installed into the base made at registration (#322), on the argument that a
+  base without domain and range has no direction for its facts. Measured on the ai-timeline
+  corpus (15 documents, DeepSeek-V3.2, `auto_extend_ontology` on, bootstrap allowed to
+  finish): the pack gives types, not predicates. With schema.org, 98% of entities were typed
+  at 90% accuracy against the Wikidata sheet, but 81% of facts still had no predicate before
+  bootstrap and 65% after, and 342 facts were dropped for `domain_mismatch`; the empty base
+  ended with 13 classes and 175 relations in the corpus's own words, 80% of entities typed
+  at 77%, and *more* entity-to-entity edges with a predicate (56% against 49%). Each
+  extraction call carried ~2k tokens instead of ~18k (the retrieved slice of a 915-class
+  pack; the full list would be ~105k and never goes in). The pack costs ten points of type
+  accuracy to leave out and buys an ontology the base grows itself; that is the trade this
+  record now makes by default, and a base that wants schema.org's vocabulary picks it in
+  the dialog. Still unmeasured: how many edges in the empty base run backwards, which the
+  direction check cannot catch without signatures.
 
 ## Open questions
 
diff --git a/docs/decisions/README.md b/docs/decisions/README.md
index c35d78677..13e43913d 100644
--- a/docs/decisions/README.md
+++ b/docs/decisions/README.md
@@ -31,7 +31,7 @@ The test for writing one: if someone (including us) looks at a piece of code in
 | 0005 | [The alert center](0005-alert-center.md) | Built · five alert kinds live, search and paging in the panel · `document.no_text_layer` still unwired |
 | 0006 | [Ontology scale and the extraction prompt](0006-ontology-scale-and-the-prompt.md) | Built · the character budget (24,000) and per-chunk retrieval live, values untested · answer keys still hand-filled |
 | 0007 | [Counting decides what becomes a relation](0007-who-decides-what-becomes-a-relation.md) | Built · adoption decided by counting (`MIN_DOCS = 2`, `MIN_SIGNALS = 3`), proposals persist (#112) · narrative verbs and `_by` folding still open |
-| 0008 | [Ontology packs as the cold start](0008-ontology-packs-as-cold-start.md) | Built · five packs embedded, multi-select at creation, schema.org by default · three open questions stay open; Chinese labels got worse |
+| 0008 | [Ontology packs as the cold start](0008-ontology-packs-as-cold-start.md) | Built · five packs embedded, multi-select at creation · no pack by default and none at registration (#580, measured) · three open questions stay open; Chinese labels got worse |
 | 0009 | [An undecided type stays empty](0009-no-type-is-a-type.md) | Implemented · `type_id` nullable, builtin classes gone · kin classes go to Review (#226), declared `disjointWith` keeps them apart (0016 B3) · `metric` / `dimension` builtin on demand (#231) · `metric` / `dimension` to retire under 0036 |
 | 0010 | [An unnamed relation stays empty](0010-no-relation-is-no-relation.md) | Implemented · `predicate_id` nullable, `related_to` gone, wording recovered by `fact_surface_predicate` · follow-ups done with 0011 |
 | 0011 | [A mapping is configuration](0011-a-mapping-is-not-a-fact.md) | Implemented (#126 / #140 / #148) · Review flow and revision history rebuilt · the evidence chain not built · revised in part by 0036: the concept becomes an attribute or a rule, the table becomes a rendered one |
diff --git a/docs/pipeline.md b/docs/pipeline.md
index 34cb2b9e9..42ccef3ae 100644
--- a/docs/pipeline.md
+++ b/docs/pipeline.md
@@ -38,7 +38,7 @@ flowchart TB
 
 **The dotted line back into extraction is the loop.** Extraction uses the ontology; when it meets a term the ontology lacks, it records the original wording; proposals flow back into the ontology; the next batch of documents is extracted with it. See [0003](decisions/0003-ontology-growth-loop.md).
 
-**Where the ontology comes from.** A new database seeds nothing. The starting point is an optional prebuilt pack (schema.org checked by default; also W3C Org, PROV-O, FOAF, IOF Core), a user-imported OWL file, or nothing at all. An empty ontology still extracts; an entity without a type simply has no type. See [0008](decisions/0008-ontology-packs-as-cold-start.md) and [0009](decisions/0009-no-type-is-a-type.md).
+**Where the ontology comes from.** A new database seeds nothing. The starting point is an optional prebuilt pack (schema.org, W3C Org, PROV-O, FOAF, IOF Core; none is checked by default), a user-imported OWL file, or nothing at all, which is the default. An empty ontology still extracts; an entity without a type simply has no type. See [0008](decisions/0008-ontology-packs-as-cold-start.md) and [0009](decisions/0009-no-type-is-a-type.md).
 
 **The bottom two boxes are the ontology's axioms at work.** The consistency check never writes `facts`; it only surfaces contradictions (the Review page's two tiers, violations and defects). Materialized inference is off by default; when on, derived facts go to a separate table, show as gold on the graph, and never close any asserted fact. See section 4.
 
diff --git a/web/src/api.ts b/web/src/api.ts
index 713fe5e6e..3d3425e0e 100644
--- a/web/src/api.ts
+++ b/web/src/api.ts
@@ -1243,10 +1243,6 @@ export type AlertGroup = {
   lines: { name?: string; error?: string; job?: string }[];
 };
 
-/** 新库默认装的本体包。建库对话框和自动建出的第一个库都从这里取，
- *  两处只能有一个答案：README 承诺的是「默认 schema.org」，不是「默认没有词表」 */
-export const DEFAULT_ONTOLOGY_PACKS = ["schema-org"];
-
 export const api = {
   health: () =>
     request<{ status: string; name: string; version: string }>(
diff --git a/web/src/i18n/en.ts b/web/src/i18n/en.ts
index 311c0b007..375cc8910 100644
--- a/web/src/i18n/en.ts
+++ b/web/src/i18n/en.ts
@@ -1064,7 +1064,7 @@ export const en = {
       packsLabel: "Bundled ontologies",
       packsHint: "Optional, and more can be imported later.",
       packsPick: "Search packs…",
-      packsNone: "None — start from the ten seed relations",
+      packsNone: "None — the ontology grows out of the documents",
       packsCount: (c: number, p: number) => `${c} classes · ${p} properties`,
       name: "Name",
       description: "Description",
diff --git a/web/src/i18n/zh.ts b/web/src/i18n/zh.ts
index 2dea0b0d7..7581bda38 100644
--- a/web/src/i18n/zh.ts
+++ b/web/src/i18n/zh.ts
@@ -949,7 +949,7 @@ export const zh: Strings = {
       packsLabel: "预置本体",
       packsHint: "可不选，之后还能再导入。",
       packsPick: "搜索本体包…",
-      packsNone: "不选 —— 从十个种子关系起步",
+      packsNone: "不选 —— 本体从文档里长出来",
       packsCount: (c: number, p: number) => `${c} 个类 · ${p} 个属性`,
       name: "名称",
       description: "描述",
diff --git a/web/src/kb.tsx b/web/src/kb.tsx
index fa560480a..594420e73 100644
--- a/web/src/kb.tsx
+++ b/web/src/kb.tsx
@@ -3,7 +3,7 @@ import { useCallback, useSyncExternalStore } from "react";
 import { useLocation, useNavigate, useParams } from "@tanstack/react-router";
 import { useQuery, useQueryClient } from "@tanstack/react-query";
 import { STREAM_KEYS } from "./queryDefaults";
-import { api, DEFAULT_ONTOLOGY_PACKS, type Kb, type Workspace } from "./api";
+import { api, type Kb, type Workspace } from "./api";
 import { kbStore, wsStore } from "./wsStore";
 
 /** 当前路径里的知识库 id。**页面都在 /kb/$kbId 之下，所以直接从路径取**——
@@ -55,13 +55,13 @@ export function useKb(): {
       if (existing.length > 0) return existing;
       // 空工作区自动创建 General——建库现在是管理员动作，非管理员会 403：
       // 静默等管理员来创建（现实中首个用户即管理员，General 总在）。
-      // **带默认本体包。** 从前这里不传 packs，于是一个新部署的第一个库一个类
-      // 都没有，第一批文档抽出来全是未分类实体；建库对话框里那个"默认 schema.org"
-      // 只对第二个库起效。第一个库恰恰是大多数人唯一会用的那个
+      // **空着起步，不带包**（#580）。从前这里装 schema.org，怕第一批文档抽出来全是
+      // 未分类实体；量过之后（#580 的对照）本体从文档里自己长出来，装包换来的类型
+      // 准确率十个点，代价是每块提示词 18k 对 2k。要包的人在建库对话框里选
       try {
         const created = await api.createKb(ws!.id, {
           name: "General",
-          ontology_packs: DEFAULT_ONTOLOGY_PACKS,
+          ontology_packs: [],
         });
         queryClient.invalidateQueries({ queryKey: ["kbs", ws!.id] });
         return [created];
diff --git a/web/src/pages/MyKbs.tsx b/web/src/pages/MyKbs.tsx
index fd036daec..c73775444 100644
--- a/web/src/pages/MyKbs.tsx
+++ b/web/src/pages/MyKbs.tsx
@@ -6,7 +6,7 @@ import { useState } from "react";
 import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 import { useNavigate, useSearch } from "@tanstack/react-router";
 import { Lock, Plus, Search } from "lucide-react";
-import { api, DEFAULT_ONTOLOGY_PACKS, type MyKb } from "../api";
+import { api, type MyKb } from "../api";
 import { S } from "../i18n";
 import { useKb } from "../kb";
 import {
@@ -192,10 +192,10 @@ function NewKbModal({
   const [name, setName] = useState("");
   const [desc, setDesc] = useState("");
   const [restricted, setRestricted] = useState(true);
-  // schema.org 默认勾选，可反选（0009）。删掉内置类之后不选任何包的库是真的空，
-  // 而空库仍然能用——但绝大多数人要的是一个已经能认出人、组织、产品的起点。
-  // 一秒装完（0008 的批量插入），所以默认装得起
-  const [packs, setPacks] = useState<string[]>([...DEFAULT_ONTOLOGY_PACKS]);
+  // 默认一个包都不勾（#580）。从前预勾 schema.org，理由是"要一个已经能认出人、
+  // 组织、产品的起点"；量过之后本体从文档里长出来的是库自己的十几个类，而 915 个
+  // 类的包让每块抽取提示词从 2k 涨到 18k tokens。要包的人在这里勾
+  const [packs, setPacks] = useState<string[]>([]);
 
   const available = useQuery({
     queryKey: ["ontologyPacks"],