I would like to create a state diagram, for example, as shown in the figure below.
I want to make this user friendly. If any user wants such a diagram, he can simply drag / drop circles / arrows and link them and put a description (1,2,3 ..... a, b, c ....), etc. It must be web .
I am not sure if there is an openource / free library for this.
How to create such a chart online?
Any idea / suggestions are welcome.
Thanks.

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