function createDependencyProposals(range) { // returning a static list of proposals, not even looking at the prefix (filtering is done by the Monaco editor), // here you could do a server side lookup return [ { label: '"lodash"', kind: monaco.languages.CompletionItemKind.Function, documentation: 'The Lodash library exported as Node.js modules.', insertText: '"lodash": "*"', range: range }, { label: '"express"', kind: monaco.languages.CompletionItemKind.Function, documentation: 'Fast, unopinionated, minimalist web framework', insertText: '"express": "*"', range: range }, { label: '"mkdirp"', kind: monaco.languages.CompletionItemKind.Function, documentation: 'Recursively mkdir, like mkdir -p', insertText: '"mkdirp": "*"', range: range }, { label: '"my-third-party-library"', kind: monaco.languages.CompletionItemKind.Function, documentation: 'Describe your library here', insertText: '"${1:my-third-party-library}": "${2:1.2.3}"', insertTextRules: monaco.languages.CompletionItemInsertTextRule.InsertAsSnippet, range: range } ]; } monaco.languages.registerCompletionItemProvider('json', { provideCompletionItems: function (model, position) { // find out if we are completing a property in the 'dependencies' object. var textUntilPosition = model.getValueInRange({ startLineNumber: 1, startColumn: 1, endLineNumber: position.lineNumber, endColumn: position.column }); var match = textUntilPosition.match( /"dependencies"\s*:\s*\{\s*("[^"]*"\s*:\s*"[^"]*"\s*,\s*)*([^"]*)?$/ ); if (!match) { return { suggestions: [] }; } var word = model.getWordUntilPosition(position); var range = { startLineNumber: position.lineNumber, endLineNumber: position.lineNumber, startColumn: word.startColumn, endColumn: word.endColumn }; return { suggestions: createDependencyProposals(range) }; } }); monaco.editor.create(document.getElementById('container'), { value: '{\n\t"dependencies": {\n\t\t\n\t}\n}\n', language: 'json' });