diff --git a/src/completions.ts b/src/completions.ts
index c2b7c4e80..d4feab044 100644
--- a/src/completions.ts
+++ b/src/completions.ts
@@ -9,6 +9,9 @@ import * as vscode from 'vscode';
 
 import * as session from './session';
 
+import { extendSelection } from './selection';
+import { cleanLine } from './lineCache';
+
 
 // Get with names(roxygen2:::default_tags())
 const roxygenTagCompletionItems = [
@@ -93,11 +96,16 @@ export class LiveCompletionItemProvider implements vscode.CompletionItemProvider
             });
         }
 
-        if (trigger === undefined || trigger === '"' || trigger === '\'') {
+        if (trigger === undefined || trigger === '[' || trigger === ',' || trigger === '"' || trigger === '\'') {
             const bracketItems = getBracketCompletionItems(document, position, token);
             items.push(...bracketItems);
         }
 
+        if (trigger === undefined || trigger === '(' || trigger === ',') {
+            const pipelineItems = getPipelineCompletionItems(document, position, token);
+            items.push(...pipelineItems);
+        }
+
         return items;
     }
 }
@@ -149,3 +157,53 @@ function getBracketCompletionItems(document: vscode.TextDocument, position: vsco
     }
     return items;
 }
+
+function getPipelineCompletionItems(document: vscode.TextDocument, position: vscode.Position, token: vscode.CancellationToken) {
+    const items: vscode.CompletionItem[] = [];
+    const range = extendSelection(position.line, (x) => document.lineAt(x).text, document.lineCount);
+    let symbol: string;
+
+    for (let i = range.startLine; i <= range.endLine; i++) {
+        if (token.isCancellationRequested) {
+            break;
+        }
+
+        const line = document.lineAt(i);
+        if (line.isEmptyOrWhitespace) {
+            continue;
+        }
+        
+        const cleanedLine = cleanLine(line.text);
+        if (cleanedLine.length === 0) {
+            continue;
+        }
+
+        const pipeSymbolIndex = line.text.search(/([\w_.]+)\s*(%.+%|\|>)/);
+        if (pipeSymbolIndex < 0) {
+            break;
+        }
+
+        const symbolPosition = new vscode.Position(i, pipeSymbolIndex);
+        const symbolRange = document.getWordRangeAtPosition(symbolPosition);
+
+        if (symbolRange !== undefined) {
+            symbol = document.getText(symbolRange);
+        }
+
+        break;
+    }
+    
+    if (!token.isCancellationRequested && symbol !== undefined) {
+        const obj = session.globalenv[symbol];
+        if (obj !== undefined && obj.names !== undefined) {
+            const doc = new vscode.MarkdownString('Element of `' + symbol + '`');
+            obj.names.map((name: string) => {
+                const item = new vscode.CompletionItem(name, vscode.CompletionItemKind.Field);
+                item.detail = '[session]';
+                item.documentation = doc;
+                items.push(item);
+            });
+        }
+    }
+    return items;
+}
diff --git a/src/extension.ts b/src/extension.ts
index a6cdbc5a2..5a2111cb7 100644
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -164,7 +164,7 @@ export async function activate(context: vscode.ExtensionContext): Promise<apiImp
         void vscode.commands.executeCommand('setContext', 'r.WorkspaceViewer:show', enableSessionWatcher);
 
         // if session watcher is active, register dyamic completion provider
-        const liveTriggerCharacters = ['', '$', '@', '"', '\'' ];
+        const liveTriggerCharacters = ['', '[', '(', ',', '$', '@', '"', '\'' ];
         vscode.languages.registerCompletionItemProvider('r', new completions.LiveCompletionItemProvider(), ...liveTriggerCharacters);
     }
 
diff --git a/src/lineCache.ts b/src/lineCache.ts
index c9a7b2800..6559e627e 100644
--- a/src/lineCache.ts
+++ b/src/lineCache.ts
@@ -48,7 +48,7 @@ function isComment(c: string) {
     return c === '#';
 }
 
-function cleanLine(text: string) {
+export function cleanLine(text: string): string {
     let cleaned = '';
     let withinQuotes = null;
     for (let i = 0; i < text.length; i++) {
diff --git a/src/selection.ts b/src/selection.ts
index bb4218a30..95cf144d1 100644
--- a/src/selection.ts
+++ b/src/selection.ts
@@ -190,8 +190,8 @@ export function extendSelection(line: number, getLine: (line: number) => string,
     endLine: number;
 } {
     const lc = new LineCache(getLine, lineCount);
-    const getLineFromCache = (x) => lc.getLineFromCache(x);
-    const getEndsInOperatorFromCache = (x) => lc.getEndsInOperatorFromCache(x);
+    const getLineFromCache = (x: number) => lc.getLineFromCache(x);
+    const getEndsInOperatorFromCache = (x: number) => lc.getEndsInOperatorFromCache(x);
     let lookingForward = true;
     /* poss[1] is the farthest point reached looking forward from line,
      and poss[0] is the farthest point reached looking backward from line. */