Change License from AGPL-3.0 to MIT

[schuenke]

License Change: AGPL-3.0 → MIT License

Overview

This PR implements the license change from AGPL-3.0 to MIT License as proposed and discussed in issue #324. This change aligns PyPulseq with the upstream MATLAB Pulseq implementation.

PR Status

⚠️ This is currently a DRAFT PR as we are still awaiting final agreement from all contributors listed in #324. However, we're opening this draft to:

• Allow the community to review the proposed changes
• Discuss the implementation approach
• Ensure we haven't missed any important aspects of the license transition

Once all contributors have confirmed their agreement in #324, this PR will be ready for final review and merge. I suggest that all maintainers approve this PR.

Changes Included

This PR includes all necessary steps for a complete license change:

Core License Updates

• LICENSE file: Completely replaced AGPL-3.0 text with standard MIT License
• pyproject.toml: Added "License :: OSI Approved :: MIT License" classifier for proper PyPI display
• README.md: Updated license badge from AGPL v3 to MIT

Verification & Compatibility

• Codebase scan: Confirmed no remaining AGPL references in the codebase (please double check)
• Documentation review: No license references found in documentation files that need updating (please double check)

Third-Party License Analysis

All existing third-party code in the repository remains compatible with the MIT License:

File	License	Status
src/pypulseq/make_adiabatic_pulse.py	BSD-3-Clause (SigPy)	✅ Compatible
src/pypulseq/utils/safe_pns_prediction.py	BSD-3-Clause (Szczepankiewicz & Witzel)	✅ Compatible
src/pypulseq/SAR/SAR_calc.py	Columbia University Copyright	✅ Compatible

All third-party licenses are permissive and shold be fully compatible with MIT. The existing copyright notices and license texts have been preserved to maintain proper attribution.

Post-Merge Actions

After this PR is merged, we should create a new PyPI release to update the license information displayed on the PyPI page.

Legal Compliance

This license change has been properly coordinated with all contributors as documented in #324, ensuring we have the necessary rights to relicense all contributed code under the MIT License. However, I would like to add that I am not a lawyer nor an expert with regard to licenses.

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
/home/runner/.local/lib/python3.12/site-packages/pypulseq
add_gradients.py	123	51	59%	44, 52, 58, 61, 75–86, 92, 120–123, 130–131, 150, 157, 162–241
add_ramps.py	36	36	0%	1–89
align.py	35	4	89%	41, 45, 69, 73
calc_duration.py	25	1	96%	37
calc_ramp.py	218	214	2%	45–353
calc_rf_bandwidth.py	27	20	26%	37–59, 63–67
check_timing.py	96	29	70%	78, 82, 107, 180, 199, 232, 239, 249–293
compress_shape.py	30	1	97%	28
convert.py	40	8	80%	42, 48, 66, 72–73, 82, 88–89
event_lib.py	96	14	85%	6–9, 48–51, 70–71, 205–210
make_adc.py	92	13	86%	63, 72–76, 79, 128, 131, 135, 141, 145, 184, 186, 188, 196
make_adiabatic_pulse.py	129	39	70%	196–200, 217–221, 229–230, 253, 259, 328–347, 451–460, 498–506
make_arbitrary_grad.py	37	7	81%	68, 71, 74, 77, 81, 83, 103
make_arbitrary_rf.py	66	55	17%	83–160
make_block_pulse.py	46	3	93%	112–116, 119
make_delay.py	9	1	89%	27
make_digital_output_pulse.py	16	2	88%	39, 47
make_extended_trapezoid.py	56	12	79%	67, 70, 76, 82, 85, 88, 91, 94, 116, 134, 136, 139
make_extended_trapezoid_area.py	93	3	97%	52, 227, 230
make_gauss_pulse.py	69	20	71%	127–131, 134–158, 165, 168
make_label.py	22	4	82%	64, 66, 68, 75
make_sigpy_pulse.py	116	31	73%	12–13, 112, 115, 119, 154, 157–161, 165, 168–169, 172–173, 188, 195, 200, 212, 215, 240–250, 264, 267, 297–307
make_sinc_pulse.py	68	10	85%	94, 100, 127–131, 135, 138–139, 142–143, 165
make_soft_delay.py	25	2	92%	102, 120
make_trapezoid.py	111	7	94%	177, 190, 196, 214, 232, 237, 255
make_trigger.py	16	2	88%	44, 52
opts.py	66	9	86%	78, 83, 102, 142, 166–170
points_to_waveform.py	9	1	89%	27
rotate.py	69	14	80%	15, 55, 66–69, 85–90, 112, 119–120
scale_grad.py	14	4	71%	28–30, 33
sigpy_pulse_opts.py	26	7	73%	34–41
split_gradient.py	39	31	21%	46–103
split_gradient_at.py	70	27	61%	63–90, 110, 114, 118–120, 154–156
traj_to_grad.py	13	9	31%	26–40
/home/runner/.local/lib/python3.12/site-packages/pypulseq/SAR
SAR_calc.py	113	98	13%	33–40, 55–62, 89–108, 129–132, 168–212, 242–246, 264–306
/home/runner/.local/lib/python3.12/site-packages/pypulseq/Sequence
block.py	405	37	91%	63, 66, 74, 80, 95, 103, 109, 120, 123, 126, 134, 139, 148, 159, 167, 207, 209, 213, 225, 274, 278, 294, 334–337, 366–367, 433, 439, 472, 541, 577, 583, 610, 648, 727
calc_grad_spectrum.py	81	76	6%	68–190
calc_pns.py	40	31	22%	45–96
ext_test_report.py	144	12	92%	23, 61, 138, 149–150, 237–243
install.py	75	42	44%	31, 52, 69, 71, 112–131, 148, 181–184, 200–212, 254–278
parula.py	4	2	50%	19–86
read_seq.py	319	68	79%	42–43, 90, 93, 105, 110, 116, 123, 132, 141, 146, 149, 157–159, 202, 207, 215–264, 294–297, 312–313, 342–359, 422, 425, 460, 468, 542, 584–588
sequence.py	815	224	73%	11–14, 104–114, 135–148, 195, 260–263, 310, 337, 354, 402, 430, 457–462, 499, 515, 606, 628, 669–672, 726, 764, 775–776, 782, 793, 799, 801, 809, 842–850, 1000, 1002, 1005, 1048–1049, 1052–1055, 1091–1101, 1110–1112, 1156–1168, 1183–1184, 1200–1218, 1252–1253, 1282, 1288, 1291, 1294, 1331, 1452–1465, 1488, 1516, 1538–1540, 1561, 1624, 1632, 1699, 1710–1723, 1735–1746, 1792–1793, 1802–1820, 1844, 1874–1882, 1914–2024, 2060, 2074–2084, 2088, 2099
write_seq.py	354	176	50%	42, 66, 69–76, 303–526
/home/runner/.local/lib/python3.12/site-packages/pypulseq/utils
cumsum.py	14	1	93%	17
safe_pns_prediction.py	126	113	10%	50–87, 102–189, 197–214, 222, 244–250, 279–286, 310–336, 344–383, 396–411, 415
tracing.py	16	6	62%	33–34, 42, 54–55, 75
/home/runner/.local/lib/python3.12/site-packages/pypulseq/utils/siemens
asc_to_hw.py	58	53	9%	21–28, 48–106
readasc.py	48	45	6%	25–100
TOTAL	4719	1675	65%

Tests	Skipped	Failures	Errors	Time
1358	21 💤	0 ❌	0 🔥	3m 46s ⏱️

[fzimmermann89]

(Despite being mostly AI slop) the PR text raises an interesting question: the SAR code does not have a separate license and copyright is held by Columbia. It was originally contributed under AGPL.

How can we relicense it?

Is the author still at Columbia and can agree in Columbia's Name to the change?
The license change issue assumed the GitHub authors hold copyright and can grant us use under the new license.