update to fixed env var name

Author: Kyle Rader

docs/GETTINGSTARTED.md

@@ -90,12 +90,12 @@ Click "Select Tools" and choose the available tools.
 
 ##### Using Token Authentication via Environment Variables
 
-For automated scenarios or when you want to use a token stored in an environment variable, you can use the `ENV_` authentication pattern:
+For automated scenarios or when you want to use a token stored in an environment variable, you can use the `envvar` authentication type:
 
-1. **Set your token in an environment variable:**
+1. **Set your token in the ADO_MCP_AUTH_TOKEN environment variable:**
 
    ```bash
-   export ADO_TOKEN="your-azure-devops-token"
+   export ADO_MCP_AUTH_TOKEN="your-azure-devops-token"
    ```
 
 2. **Update your `.vscode/mcp.json` to use token authentication:**
@@ -112,7 +112,7 @@ For automated scenarios or when you want to use a token stored in an environment
        "ado": {
          "type": "stdio",
          "command": "npx",
-         "args": ["-y", "@azure-devops/mcp", "${input:ado_org}", "--authentication", "ENV_ADO_TOKEN"]
+         "args": ["-y", "@azure-devops/mcp", "${input:ado_org}", "--authentication", "envvar"]
        }
      }
    }

docs/TROUBLESHOOTING.md

@@ -50,18 +50,18 @@
 
 ### Token Authentication via Environment Variables
 
-For automated scenarios or when you want to use a token stored in an environment variable, you can use the `ENV_` authentication pattern:
+For automated scenarios or when you want to use a token stored in an environment variable, you can use the `envvar` authentication type:
 
-1. **Set your token in an environment variable:**
+1. **Set your token in the ADO_MCP_AUTH_TOKEN environment variable:**
 
    ```bash
-   export ADO_TOKEN="your-azure-devops-token"
+   export ADO_MCP_AUTH_TOKEN="your-azure-devops-token"
    ```
 
-2. **Use the ENV\_ authentication pattern:**
+2. **Use the envvar authentication type:**
 
    ```bash
-   npx @azure-devops/mcp myorg --authentication ENV_ADO_TOKEN
+   npx @azure-devops/mcp myorg --authentication envvar
    ```
 
 3. **For MCP configuration files, update your `.vscode/mcp.json`:**
@@ -78,7 +78,7 @@ For automated scenarios or when you want to use a token stored in an environment
        "ado": {
          "type": "stdio",
          "command": "npx",
-         "args": ["-y", "@azure-devops/mcp", "${input:ado_org}", "--authentication", "ENV_ADO_TOKEN"]
+         "args": ["-y", "@azure-devops/mcp", "${input:ado_org}", "--authentication", "envvar"]
        }
      }
    }

src/auth.ts

@@ -61,28 +61,19 @@ class OAuthAuthenticator {
 }
 
 function createAuthenticator(type: string, tenantId?: string): () => Promise<string> {
-  // Check for ENV_ prefix pattern for environment variable authentication
-  if (type.startsWith("ENV_")) {
-    const envVarName = type.substring(4); // Remove "ENV_" prefix
-    if (!envVarName) {
-      throw new Error("Environment variable name is required after ENV_ prefix. Example: ENV_ADO_MCP_TOKEN");
-    }
-
-    return async () => {
-      const token = process.env[envVarName];
-      if (!token) {
-        throw new Error(`Environment variable '${envVarName}' is not set or empty. Please set it with a valid Azure DevOps Personal Access Token.`);
-      }
-      return token;
-    };
-  }
-
   switch (type) {
+    case "envvar":
+      // Read token from fixed environment variable
+      return async () => {
+        const token = process.env["ADO_MCP_AUTH_TOKEN"];
+        if (!token) {
+          throw new Error("Environment variable 'ADO_MCP_AUTH_TOKEN' is not set or empty. Please set it with a valid Azure DevOps Personal Access Token.");
+        }
+        return token;
+      };
+
     case "azcli":
-    case "env":
-      if (type !== "env") {
-        process.env.AZURE_TOKEN_CREDENTIALS = "dev";
-      }
+      process.env.AZURE_TOKEN_CREDENTIALS = "dev";
       let credential: TokenCredential = new DefaultAzureCredential(); // CodeQL [SM05138] resolved by explicitly setting AZURE_TOKEN_CREDENTIALS
       if (tenantId) {
         // Use Azure CLI credential if tenantId is provided for multi-tenant scenarios

src/index.ts

@@ -44,8 +44,9 @@ const argv = yargs(hideBin(process.argv))
   })
   .option("authentication", {
     alias: "a",
-    describe: "Type of authentication to use. Supported values are 'interactive', 'azcli', 'env', or 'ENV_<VAR_NAME>' to read token from environment variable (default: 'interactive')",
+    describe: "Type of authentication to use",
     type: "string",
+    choices: ["interactive", "azcli", "envvar"],
     default: defaultAuthenticationType,
   })
   .option("tenant", {