Yes
Most weak-copyleft licenses (including GNU Lesser GPL v2.1) are designed to combine with GPL-family ones. Verify the specific weak-copyleft license version against GNU Affero GPL v3.0 or later's compatibility list (FSF maintains an authoritative one).
| License | Family | Patent grant |
|---|---|---|
| GNU Lesser GPL v2.1 (LGPL-2.1) | weak-copyleft | No (implicit at most) |
| GNU Affero GPL v3.0 or later (AGPL-3.0-or-later) | network-copyleft | Yes |
GNU Lesser GPL v2.1: Library copyleft: dynamic linking permitted from non-LGPL code without triggering full copyleft.
GNU Affero GPL v3.0 or later: AGPL-3.0 with explicit upgrade path.
If you found this page because you're trying to figure out whether shipping a particular dependency is safe, the answer above is a starting point — not a substitute for reading the actual licenses or talking to a lawyer when stakes are high.
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