TypeError: jsonify does not accept multiple top-level objects

TypeError: jsonify multiple top-level objects

$ flask --app app.py run
Traceback (most recent call last):
  File "app.py", line 10, in api
    return jsonify({'a': 1}, {'b': 2})
TypeError: jsonify accepts at most one top-level object

Why this happens

jsonify expects a single mapping or sequence to serialize. Passing multiple positional arguments is ambiguous: should it be a list, a dict merge, or a tuple? Flask raises TypeError to enforce clarity.

Fix

Wrap values in a single dict or list, or merge them before calling jsonify.

Wrong code

from flask import Flask, jsonify
app = Flask(__name__)

@app.route('/api')
def api():
    return jsonify({'a': 1}, {'b': 2})

Fixed code

from flask import Flask, jsonify
app = Flask(__name__)

@app.route('/api')
def api():
    return jsonify({'a': 1, 'b': 2})

Tip

For multiple items, consider returning a list: jsonify([obj1, obj2]).