Add typing in api.py #406

Job	Run time
Test on python 3.7 and ubuntu-latest	35s
Test on python 3.7 and windows-latest	23s
Test on python 3.7 and macos-latest	24s
Test on python 3.8 and ubuntu-latest	35s
Test on python 3.8 and windows-latest	23s
Test on python 3.8 and macos-latest	18s
Test on python 3.9 and ubuntu-latest	17s
Test on python 3.9 and windows-latest	1s
Test on python 3.9 and macos-latest	1s
Test on python 3.10 and ubuntu-latest	36s
Test on python 3.10 and windows-latest	25s
Test on python 3.10 and macos-latest	30s
Test on python 3.11 and ubuntu-latest	34s
Test on python 3.11 and windows-latest	22s
Test on python 3.11 and macos-latest	24s
Test on python 3.12 and ubuntu-latest	35s
Test on python 3.12 and windows-latest	19s
Test on python 3.12 and macos-latest	21s
	7m 3s

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