Add Dev Proxy agent skill. Closes #341

Closes #341

Author: garrytrinder

.gitignore

@@ -6,3 +6,6 @@ node_modules
 
 # Coverage reports
 coverage/
+
+# Skills fetched at build time
+skills/

.vscode/launch.json

@@ -15,7 +15,7 @@
 			"outFiles": [
 				"${workspaceFolder}/dist/**/*.js"
 			],
-			"preLaunchTask": "${defaultBuildTask}"
+			"preLaunchTask": "pre-launch"
 		}
 	]
 }

.vscode/tasks.json

@@ -48,6 +48,25 @@
 				"npm: watch-tests"
 			],
 			"problemMatcher": []
+		},
+		{
+			"label": "fetch-skill",
+			"type": "shell",
+			"command": "bash scripts/fetch-skill.sh",
+			"presentation": {
+				"reveal": "silent",
+				"group": "build"
+			},
+			"problemMatcher": []
+		},
+		{
+			"label": "pre-launch",
+			"dependsOn": [
+				"fetch-skill",
+				"npm: watch"
+			],
+			"dependsOrder": "sequence",
+			"problemMatcher": []
 		}
 	]
 }

.vscodeignore

@@ -3,6 +3,8 @@
 out/**
 node_modules/**
 src/**
+scripts/**
+skills/**
 .gitignore
 .yarnrc
 webpack.config.js

CHANGELOG.md

@@ -9,6 +9,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [1.27.1] - Unreleased
 
+### Added:
+
+- Agent Skill: [Dev Proxy](https://github.com/dotnet/dev-proxy/tree/main/skills/dev-proxy)
+
 ### Fixed:
 
 - Problem matcher: `$devproxy-watch` `beginsPattern` updated to match actual Dev Proxy output

README.md

@@ -265,6 +265,12 @@ Run Dev Proxy as a VS Code task for integration with build workflows.
 
 This extension includes an MCP server for AI-assisted development. See [Dev Proxy MCP Server](https://github.com/dev-proxy-tools/mcp) for available tools.
 
+## Agent Skill
+
+This extension contributes a Dev Proxy [agent skill](https://code.visualstudio.com/docs/copilot/customization/agent-skills) for GitHub Copilot. The skill teaches Copilot how to configure Dev Proxy, mock API responses, simulate errors, test rate limiting, and more — without you having to explain the setup every time.
+
+The skill is automatically available when the extension is installed. Type `/dev-proxy` in Copilot Chat to invoke it, or let Copilot load it automatically when your question is relevant.
+
 ## Troubleshooting
 
 **View debug logs**

package-lock.json

@@ -5,7 +5,7 @@
   "version": "1.27.1",
   "publisher": "garrytrinder",
   "engines": {
-    "vscode": "^1.101.0"
+    "vscode": "^1.109.0"
   },
   "categories": [
     "Snippets",
@@ -120,6 +120,11 @@
         "label": "Dev Proxy"
       }
     ],
+    "chatSkills": [
+      {
+        "path": "./dist/skills/dev-proxy/SKILL.md"
+      }
+    ],
     "menus": {
       "editor/title": [
         {
@@ -273,7 +278,8 @@
   "icon": "dist/icon.png",
   "homepage": "https://github.com/garrytrinder/dev-proxy-toolkit/blob/main/README.md",
   "scripts": {
-    "vscode:prepublish": "npm run package",
+    "vscode:prepublish": "npm run fetch-skill && npm run package",
+    "fetch-skill": "bash scripts/fetch-skill.sh",
     "clean": "rm -rf out dist",
     "compile": "webpack",
     "watch": "webpack --watch",
@@ -292,7 +298,7 @@
     "@types/node": "^24.5.2",
     "@types/semver": "^7.7.1",
     "@types/sinon": "17.0.4",
-    "@types/vscode": "1.101.0",
+    "@types/vscode": "1.109.0",
     "@typescript-eslint/eslint-plugin": "8.44.1",
     "@typescript-eslint/parser": "8.44.1",
     "@vscode/test-cli": "^0.0.12",

package.json

@@ -0,0 +1,44 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Downloads the Dev Proxy skill from dotnet/dev-proxy main branch.
+# The skill files (SKILL.md + references/) are fetched into skills/dev-proxy/
+# and are .gitignored — they're bundled into the VSIX at build time.
+
+REPO="dotnet/dev-proxy"
+BRANCH="main"
+SKILL_PATH="skills/dev-proxy"
+TARGET_DIR="skills/dev-proxy"
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+ROOT_DIR="$(cd "$SCRIPT_DIR/.." && pwd)"
+
+echo "Fetching Dev Proxy skill from $REPO@$BRANCH..."
+
+# Clean existing skill directory
+rm -rf "$ROOT_DIR/$TARGET_DIR"
+mkdir -p "$ROOT_DIR/$TARGET_DIR/references"
+
+BASE_URL="https://raw.githubusercontent.com/$REPO/$BRANCH/$SKILL_PATH"
+
+# Download SKILL.md
+curl -fsSL "$BASE_URL/SKILL.md" -o "$ROOT_DIR/$TARGET_DIR/SKILL.md"
+
+# Download reference files
+REFERENCES=(
+  "analyze-api-usage.md"
+  "best-practices.md"
+  "ci-cd-integration.md"
+  "configuration.md"
+  "installation.md"
+  "mock-api-responses.md"
+  "plugin-catalog.md"
+  "test-api-resilience.md"
+  "test-llm-apps.md"
+)
+
+for ref in "${REFERENCES[@]}"; do
+  curl -fsSL "$BASE_URL/references/$ref" -o "$ROOT_DIR/$TARGET_DIR/references/$ref"
+done
+
+echo "Dev Proxy skill fetched successfully."

scripts/fetch-skill.sh

@@ -52,6 +52,7 @@ const extensionConfig = {
         {from: 'src/snippets/yaml-snippets.json', to: '[name][ext]'},
         {from: 'src/icon.png', to: '[name][ext]'},
         {from: 'LICENSE', to: '[name][ext]'},
+        {from: 'skills', to: 'skills', globOptions: {ignore: ['**/.DS_Store']}},
       ],
     }),
   ],