diff --git a/README.md b/README.md
index c1b21a9..bcc8991 100644
--- a/README.md
+++ b/README.md
@@ -332,7 +332,7 @@ Errors throw a `ZenRowsCrawlError` with `status`, `code`, `detail` and `retryAft
 
 `content()` takes a content id, a `content_url` or a result, and throws a `TypeError` when it cannot read a content id from it. Requests retry network errors and 502/503/504 (and 429 on reads) when it is safe; a `create()` is retried only with an `idempotencyKey`, and a `stop()` as described above.
 
-`outputFormat` takes `"html"`; without it a crawl returns URLs only. `maxPages` and `maxItems` default to 100 each. A crawl created without `depth` has no `depth` field; one created with it echoes it. Response enum fields (`status`, `stop_reason`, `error.code`, `content_status`) are `Extensible<...>`: the known values plus any `string`. A failed crawl carries `error.code` and `error.detail`. So does a crawl that ran out of credits, or whose API key hit a credit cap: it ends `stopped`, with `error.code` `insufficient_credits` or `api_key_cap_reached` and no `stop_reason`, and the pages it fetched before that stay readable. A download line's `content` is a string, or an object for a crawl that returns JSON.
+`outputFormat` takes `"html"`; without it a crawl returns URLs only. `maxPages` and `maxItems` default to 100 each. A crawl created without `depth` has no `depth` field; one created with it echoes it. Response enum fields (`status`, `stop_reason`, `error.code`, `content_status`) are `Extensible<...>`: the known values plus any `string`. A crawl whose pages held nothing new to follow (no link, only links to other sites, or only links the patterns reject) ends `completed` with no results and no `error`: check the patterns against the URLs the start page links to. A failed crawl carries `error.code` and `error.detail`. So does a crawl that ran out of credits, or whose API key hit a credit cap: it ends `stopped`, with `error.code` `insufficient_credits` or `api_key_cap_reached` and no `stop_reason`, and the pages it fetched before that stay readable. A download line's `content` is a string, or an object for a crawl that returns JSON.
 
 The crawl client (`ZenRowsCrawlClient`) also works standalone. Both forms take the same options:
 
diff --git a/acceptance/crawl/README.md b/acceptance/crawl/README.md
index c61773c..ad098de 100644
--- a/acceptance/crawl/README.md
+++ b/acceptance/crawl/README.md
@@ -78,7 +78,7 @@ and signal checks.
 | 16 | Errors carry the server code | SDKs: `code` holds it, empty when the body has none; MCP, CLI: `server_code` |
 | 17 | Naming | the API's operation and parameter names, in this surface's casing |
 | 18 | Copy | Crawl is "new", never "beta"; one "still evolving" line; the 429 limit reads as the account's active jobs, shared with Batch |
-| 19 | Failed crawl | an include pattern that matches nothing ends `failed` with `no_items_found`; SDKs return it, not raise it; MCP and CLI say `ok: false` (CLI: exit 1, `CRAWL_FAILED`) |
+| 19 | Patterns match nothing | an include pattern that matches nothing ends `completed` with 0 results and no `error`; SDKs return it; MCP and CLI say `ok: true` (CLI: exit 0) |
 | 20 | Results after stop | the html crawl is stopped while its pages are still being fetched: reading its results ends at once (MCP and CLI: `partial: false`, no note to call again), and the same URLs come back once the pages in flight finish |
 | 21 | Documented defaults | a create without `max_pages` and `max_items` gets the default the docs state (100) |
 
diff --git a/acceptance/crawl/contract.lock b/acceptance/crawl/contract.lock
new file mode 100644
index 0000000..435df9b
--- /dev/null
+++ b/acceptance/crawl/contract.lock
@@ -0,0 +1,3 @@
+1adcbc2fd87e3f508317f3ce24c3d48573aec657
+pending GET /healthz
+pending POST /internal/v1/crawls/{crawl_id}/stop
diff --git a/acceptance/crawl/surface/harness.mjs b/acceptance/crawl/surface/harness.mjs
index 763d581..f0b3b5d 100644
--- a/acceptance/crawl/surface/harness.mjs
+++ b/acceptance/crawl/surface/harness.mjs
@@ -10,7 +10,7 @@ export const HAS_KEY = KEY.length > 0;
 export const CRAWL_URL = process.env.CRAWL_URL;
 export const INCLUDE = process.env.CRAWL_INCLUDE;
 export const API_BASE = process.env.CRAWL_API_BASE || "https://api.zenrows.com/v1";
-/** An include pattern no URL contains: the crawl keeps nothing and ends failed (check 19). */
+/** An include pattern no URL contains: the crawl keeps nothing and completes (check 19). */
 export const NO_MATCH = "/crawl-acceptance-matches-nothing/";
 /** The default every client documents for max_pages and max_items (check 21). */
 export const DOCUMENTED_DEFAULT = 100;
diff --git a/acceptance/crawl/surface/test.mjs b/acceptance/crawl/surface/test.mjs
index 42fc8f7..9bc00d0 100644
--- a/acceptance/crawl/surface/test.mjs
+++ b/acceptance/crawl/surface/test.mjs
@@ -702,21 +702,21 @@ await check(
 );
 await cap.close();
 
-// ---------- 19-21: a failed crawl, results after a stop, the documented defaults ----------
+// ---------- 19-21: patterns that match nothing, results after a stop, the documented defaults ----------
 await liveCheck(
   "19",
-  "Failed crawl",
-  "a crawl that keeps nothing ends failed (no_items_found); wait returns it, not raises",
+  "Patterns match nothing",
+  "a crawl whose patterns match nothing ends completed with 0 results and no error",
   async () => {
     F = await create({ url: CRAWL_URL, depth: 1, includePatterns: [H.NO_MATCH] });
     const w = await client.wait(F.crawl_id);
+    const urls = [];
+    for await (const x of client.results(F.crawl_id)) urls.push(x.url);
     const ok =
-      w.status === "failed" &&
-      w.error?.code === "no_items_found" &&
-      typeof w.error?.detail === "string";
+      w.status === "completed" && !w.error && w.coverage.items_found === 0 && urls.length === 0;
     return {
       status: passIf(ok),
-      actual: `${F.crawl_id}: ${w.status}; error ${JSON.stringify(w.error)}; returned, no exception`,
+      actual: `${F.crawl_id}: ${w.status}; items_found ${w.coverage.items_found}, ${urls.length} results; error ${JSON.stringify(w.error ?? null)}`,
       evidence: JSON.stringify(w),
     };
   },
diff --git a/acceptance/crawl/tools/report.py b/acceptance/crawl/tools/report.py
index 94488f8..83e01e2 100644
--- a/acceptance/crawl/tools/report.py
+++ b/acceptance/crawl/tools/report.py
@@ -18,7 +18,7 @@
     "1": "Create", "2": "Create with html", "3": "Idempotency", "4": "Wait", "5": "Wait runs out", "6": "Get",
     "7": "List", "8": "Results", "9": "Content", "10": "Download", "11": "Stop", "12": "Not found",
     "13": "Invalid input", "14": "Gated option", "15": "Bad key", "16": "Errors carry the server code",
-    "17": "Naming", "18": "Copy", "19": "Failed crawl", "20": "Results after stop", "21": "Documented defaults",
+    "17": "Naming", "18": "Copy", "19": "Patterns match nothing", "20": "Results after stop", "21": "Documented defaults",
 }
 # The API's operation and parameter names. Each surface uses them in its own casing.
 CANON_OPS = ["create", "get", "list", "results", "content", "download", "stop", "wait"]
diff --git a/src/crawl/client.ts b/src/crawl/client.ts
index a79fcc7..1ebeaf0 100644
--- a/src/crawl/client.ts
+++ b/src/crawl/client.ts
@@ -50,7 +50,10 @@ export interface CreateCrawlParams {
   maxItems?: number;
   /** Stop once this many pages are fetched, 1–100000; bounds the cost. Server default 100. */
   maxPages?: number;
-  /** Keep a URL only if it contains at least one of these substrings. */
+  /**
+   * Keep a URL only if it contains at least one of these substrings. A crawl whose patterns reject
+   * every link ends `completed` with no results and no `error`.
+   */
   includePatterns?: string[];
   /** Drop a URL that contains any of these substrings, even if it matches an include pattern. */
   excludePatterns?: string[];
diff --git a/src/crawl/types.ts b/src/crawl/types.ts
index 541c2ed..ebc5c0a 100644
--- a/src/crawl/types.ts
+++ b/src/crawl/types.ts
@@ -11,6 +11,10 @@ export type CrawlStopReason = "max_items" | "max_pages" | "user";
 /**
  * Why a crawl failed (`status: failed`), or why it stopped on credits: `insufficient_credits` and
  * `api_key_cap_reached` come with `status: stopped`, and the pages fetched before that stay readable.
+ * `seed_unreachable`: the start page could not be reached, was blocked, or came back empty, with no
+ * visible text and no link. `no_items_found`: the crawl read the start page but found no data it could
+ * use, so it had nothing to follow; start from a listing or product page. A crawl that returns nothing
+ * for any other reason is not a failure: it ends `completed` with no results.
  */
 export type CrawlErrorCode =
   | "insufficient_credits"