Add typing in api.py #413

Job	Run time
Test on python 3.7 and ubuntu-latest	2m 12s
Test on python 3.7 and windows-latest	2m 46s
Test on python 3.7 and macos-latest	19s
Test on python 3.8 and ubuntu-latest	1m 41s
Test on python 3.8 and windows-latest	2m 2s
Test on python 3.8 and macos-latest	47s
Test on python 3.9 and ubuntu-latest	1m 46s
Test on python 3.9 and windows-latest	2m 49s
Test on python 3.9 and macos-latest	17s
Test on python 3.10 and ubuntu-latest	1m 49s
Test on python 3.10 and windows-latest	2m 3s
Test on python 3.10 and macos-latest	17s
Test on python 3.11 and ubuntu-latest	1m 36s
Test on python 3.11 and windows-latest	1m 49s
Test on python 3.11 and macos-latest	16s
Test on python 3.12 and ubuntu-latest	1m 34s
Test on python 3.12 and windows-latest	3m 1s
Test on python 3.12 and macos-latest	17s
	27m 21s

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