@mcp-layer/schema - npm Package Compare versions

Comparing version 1.0.1 to 1.0.2

package.json

 {
   "name": "@mcp-layer/schema",
-  "version": "1.0.1",
+  "version": "1.0.2",
   "description": "Extract and normalize MCP schemas into a unified Zod-based format.",
@@ -35,9 +35,10 @@ "repository": {
     "ajv": "^8.17.1",
-    "zod": "^3.25.76"
+    "zod": "^3.25.76",
+    "@mcp-layer/error": "0.2.0"
   },
   "devDependencies": {
-    "@mcp-layer/attach": "1.1.0",
-    "@mcp-layer/config": "1.0.0",
-    "@mcp-layer/connect": "1.0.0",
-    "@mcp-layer/test-server": "1.0.0"
+    "@mcp-layer/attach": "1.1.1",
+    "@mcp-layer/config": "1.0.1",
+    "@mcp-layer/connect": "1.0.1",
+    "@mcp-layer/test-server": "1.0.1"
   },
@@ -44,0 +45,0 @@ "scripts": {

README.md

@@ -5,2 +5,15 @@ # @mcp-layer/schema
 
+## Table of Contents
+
+- [Installation](#installation)
+- [Usage](#usage)
+- [What this package does](#what-this-package-does)
+- [Output shape (authoritative)](#output-shape-authoritative)
+- [MCP Apps support](#mcp-apps-support)
+- [Generator guidance](#generator-guidance)
+- [Responsibilities and lifecycle](#responsibilities-and-lifecycle)
+- [Error handling](#error-handling)
+- [JSON Schema vs Zod](#json-schema-vs-zod)
+- [Runtime Error Reference](#runtime-error-reference)
+
 ## Installation
@@ -147,1 +160,34 @@
 Zod validators are produced to allow direct runtime validation, but the original JSON Schema is preserved in `detail.input.json` and `detail.output.json` so generators can emit OpenAPI, JSON Schema, or other schema formats without losing fidelity.
+
+## Runtime Error Reference
+
+This section is written for high-pressure debugging moments. Each entry maps directly to schema extraction preconditions.
+
+<a id="error-49ae61"></a>
+### Expected a Session instance.
+
+Thrown from: `extract`
+
+This happens when `extract(link)` is called without a connected `Session` object (or with an object that does not expose `.client`). The extractor relies on MCP client capabilities and list calls.
+
+Step-by-step resolution:
+1. Verify you are passing the `Session` returned by `connect(...)` or `attach(...)`.
+2. Confirm session setup completed and `session.client` is available.
+3. Avoid passing raw MCP client objects directly; wrap flows around `Session`.
+4. Add an integration test that extracts from a real connected session.
+
+<details>
+<summary>Fix Example: extract schemas from a connected Session</summary>
+
+```js
+const session = await connect(config, 'local-dev');
+const catalog = await extract(session);
+console.log(catalog.items.length);
+await session.close();
+```
+
+</details>
+
+## License
+
+MIT

src/index.js

 import Ajv from 'ajv';
 import { z } from 'zod';
+import { LayerError } from '@mcp-layer/error';
 
@@ -21,9 +22,5 @@ const ajv = new Ajv({ allErrors: true, strict: false });
 function ismissing(error) {
-  if (!error || typeof error !== 'object') {
-    return false;
-  }
+  if (!error || typeof error !== 'object') return false;
   const code = 'code' in error ? error.code : undefined;
-  if (code === -32601) {
-    return true;
-  }
+  if (code === -32601) return true;
   const message = 'message' in error ? String(error.message) : '';
@@ -48,5 +45,3 @@ return message.includes('Method') && message.includes('not found');
     const ok = check(value);
-    if (ok) {
-      return;
-    }
+    if (ok) return;
     const text = validator.errorsText(check.errors, { dataVar: 'value' });
@@ -93,9 +88,5 @@ ctx.addIssue({ code: z.ZodIssueCode.custom, message: text });
     const batch = pull(result);
-    if (Array.isArray(batch)) {
-      list.push(...batch);
-    }
+    if (Array.isArray(batch)) list.push(...batch);
     cursor = result.nextCursor;
-    if (!cursor) {
-      break;
-    }
+    if (!cursor) break;
   }
@@ -196,5 +187,3 @@
   } catch (error) {
-    if (ismissing(error)) {
-      return [];
-    }
+    if (ismissing(error)) return [];
     throw error;
@@ -241,8 +230,4 @@ }
   const out = {};
-  if (Array.isArray(item.icons)) {
-    out.icons = item.icons;
-  }
-  if (isrecord(item._meta)) {
-    out._meta = item._meta;
-  }
+  if (Array.isArray(item.icons)) out.icons = item.icons;
+  if (isrecord(item._meta)) out._meta = item._meta;
   return out;
@@ -258,5 +243,3 @@ }
   const out = meta(tool);
-  if (isrecord(tool.annotations)) {
-    out.annotations = tool.annotations;
-  }
+  if (isrecord(tool.annotations)) out.annotations = tool.annotations;
   return out;
@@ -271,8 +254,4 @@ }
 function tooltitle(tool) {
-  if (typeof tool.title === 'string') {
-    return tool.title;
-  }
-  if (isrecord(tool.annotations) && typeof tool.annotations.title === 'string') {
-    return tool.annotations.title;
-  }
+  if (typeof tool.title === 'string') return tool.title;
+  if (isrecord(tool.annotations) && typeof tool.annotations.title === 'string') return tool.annotations.title;
   return undefined;
@@ -287,22 +266,10 @@ }
 function uiitem(item) {
-  if (!isrecord(item._meta)) {
-    return undefined;
-  }
-  if (!isrecord(item._meta.ui)) {
-    return undefined;
-  }
+  if (!isrecord(item._meta)) return undefined;
+  if (!isrecord(item._meta.ui)) return undefined;
   const ui = /** @type {Record<string, unknown>} */ (item._meta.ui);
   const out = {};
-  if (typeof ui.resourceUri === 'string') {
-    out.resourceUri = ui.resourceUri;
-  }
-  if (typeof ui.csp === 'string') {
-    out.csp = ui.csp;
-  }
-  if (Array.isArray(ui.permissions)) {
-    out.permissions = ui.permissions;
-  }
-  if (Object.keys(out).length === 0) {
-    return undefined;
-  }
+  if (typeof ui.resourceUri === 'string') out.resourceUri = ui.resourceUri;
+  if (typeof ui.csp === 'string') out.csp = ui.csp;
+  if (Array.isArray(ui.permissions)) out.permissions = ui.permissions;
+  if (Object.keys(out).length === 0) return undefined;
   return out;
@@ -322,8 +289,4 @@ }
 
-  if (isrecord(tool.outputSchema)) {
-    detail.output = output;
-  }
-  if (ui) {
-    detail.ui = ui;
-  }
+  if (isrecord(tool.outputSchema)) detail.output = output;
+  if (ui) detail.ui = ui;
 
@@ -387,5 +350,3 @@ return {
 function promptinput(prompt) {
-  if (!Array.isArray(prompt.arguments)) {
-    return wrapschema(undefined);
-  }
+  if (!Array.isArray(prompt.arguments)) return wrapschema(undefined);
 
@@ -396,14 +357,8 @@ const properties = {};
   for (const item of prompt.arguments) {
-    if (!isrecord(item)) {
-      continue;
-    }
-    if (typeof item.name !== 'string' || item.name.length === 0) {
-      continue;
-    }
+    if (!isrecord(item)) continue;
+    if (typeof item.name !== 'string' || item.name.length === 0) continue;
     properties[item.name] = {
       description: typeof item.description === 'string' ? item.description : undefined
     };
-    if (item.required === true) {
-      required.push(item.name);
-    }
+    if (item.required === true) required.push(item.name);
   }
@@ -482,3 +437,7 @@
   if (!link || !link.client) {
-    throw new Error('Expected a Session instance.');
+    throw new LayerError({
+      name: 'schema',
+      method: 'extract',
+      message: 'Expected a Session instance.',
+    });
   }
@@ -498,5 +457,3 @@
 
-  if (caps && caps.tools) {
-    data.tools = await tools(client);
-  }
+  if (caps && caps.tools) data.tools = await tools(client);
 
@@ -508,5 +465,3 @@ if (caps && caps.resources) {
 
-  if (caps && caps.prompts) {
-    data.prompts = await prompts(client);
-  }
+  if (caps && caps.prompts) data.prompts = await prompts(client);
 
@@ -513,0 +468,0 @@ const items = normalize(data);

No alert changes

Improved metrics

Total package byte prevSize

22810

6.49%

Number of lines in readme file

192

31.51%

Worsened metrics

Dependency count

3

50%

Lines of code

413

-9.83%

Dependency changes

• + Added

  @mcp-layer/error@0.2.0

• + Added

  @mcp-layer/error@0.2.0
  (transitive)