function createDependencyProposals() { // 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": "*"' }, { label: '"express"', kind: monaco.languages.CompletionItemKind.Function, documentation: "Fast, unopinionated, minimalist web framework", insertText: '"express": "*"' }, { label: '"mkdirp"', kind: monaco.languages.CompletionItemKind.Function, documentation: "Recursively mkdir, like mkdir -p", insertText: '"mkdirp": "*"' }, { 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 } ]; } 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*)*([^"]*)?$/); var suggestions = match ? createDependencyProposals() : []; return { suggestions: suggestions }; } }); monaco.editor.create(document.getElementById("container"), { value: "{\n\t\"dependencies\": {\n\t\t\n\t}\n}\n", language: "json" });