diff --git a/Cargo.lock b/Cargo.lock
index 365d2e7..f519ee8 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -187,7 +187,7 @@ dependencies = [
  "miniz_oxide",
  "object",
  "rustc-demangle",
- "windows-link 0.2.1",
+ "windows-link",
 ]
 
 [[package]]
@@ -1662,7 +1662,7 @@ dependencies = [
  "log",
  "presser",
  "thiserror 2.0.18",
- "windows 0.61.3",
+ "windows",
 ]
 
 [[package]]
@@ -2015,15 +2015,6 @@ dependencies = [
  "serde_core",
 ]
 
-[[package]]
-name = "indoc"
-version = "2.0.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "79cf5c93f93228cf8efb3ba362535fb11199ac548a09ce117c9b1adc3030d706"
-dependencies = [
- "rustversion",
-]
-
 [[package]]
 name = "inflections"
 version = "1.1.1"
@@ -2164,7 +2155,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d7c4b02199fee7c5d21a5ae7d8cfa79a6ef5bb2fc834d6e9058e89c825efdc55"
 dependencies = [
  "cfg-if",
- "windows-link 0.2.1",
+ "windows-link",
 ]
 
 [[package]]
@@ -2174,7 +2165,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "754ca22de805bb5744484a5b151a9e1a8e837d5dc232c2d7d8c2e3492edc8b60"
 dependencies = [
  "cfg-if",
- "windows-link 0.2.1",
+ "windows-link",
 ]
 
 [[package]]
@@ -2294,15 +2285,6 @@ version = "2.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f8ca58f447f06ed17d5fc4043ce1b10dd205e060fb3ce5b979b8ed8e59ff3f79"
 
-[[package]]
-name = "memoffset"
-version = "0.9.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "488016bfae457b036d996092f6cb448677611ce4449e970ceaf42695203f218a"
-dependencies = [
- "autocfg",
-]
-
 [[package]]
 name = "minimal-lexical"
 version = "0.2.1"
@@ -2720,7 +2702,7 @@ dependencies = [
  "libc",
  "redox_syscall 0.5.18",
  "smallvec",
- "windows-link 0.2.1",
+ "windows-link",
 ]
 
 [[package]]
@@ -2891,37 +2873,32 @@ dependencies = [
 
 [[package]]
 name = "pyo3"
-version = "0.24.2"
+version = "0.29.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e5203598f366b11a02b13aa20cab591229ff0a89fd121a308a5df751d5fc9219"
+checksum = "4688ddedf473e32662b9b067670129a8afb8c18e351482c70d62ba4a88171e8b"
 dependencies = [
- "cfg-if",
- "indoc",
  "libc",
- "memoffset",
  "once_cell",
  "portable-atomic",
  "pyo3-build-config",
  "pyo3-ffi",
  "pyo3-macros",
- "unindent",
 ]
 
 [[package]]
 name = "pyo3-build-config"
-version = "0.24.2"
+version = "0.29.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "99636d423fa2ca130fa5acde3059308006d46f98caac629418e53f7ebb1e9999"
+checksum = "f41027e41b4bd03f6e60f9f417fe24a6341a6bb744edd62b6f709f2a52ea30e9"
 dependencies = [
- "once_cell",
  "target-lexicon",
 ]
 
 [[package]]
 name = "pyo3-ffi"
-version = "0.24.2"
+version = "0.29.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "78f9cf92ba9c409279bc3305b5409d90db2d2c22392d443a87df3a1adad59e33"
+checksum = "e591a95526fead067432c3b3a33fc74770b87b1e04e73671090d9c2055a2b327"
 dependencies = [
  "libc",
  "pyo3-build-config",
@@ -2929,9 +2906,9 @@ dependencies = [
 
 [[package]]
 name = "pyo3-macros"
-version = "0.24.2"
+version = "0.29.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0b999cb1a6ce21f9a6b147dcf1be9ffedf02e0043aec74dc390f3007047cecd9"
+checksum = "73225868fc1cd84eef2c3c230ddb91273bf1de46aeb8a4248da76d32a0924a1c"
 dependencies = [
  "proc-macro2",
  "pyo3-macros-backend",
@@ -2941,13 +2918,12 @@ dependencies = [
 
 [[package]]
 name = "pyo3-macros-backend"
-version = "0.24.2"
+version = "0.29.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "822ece1c7e1012745607d5cf0bcb2874769f0f7cb34c4cde03b9358eb9ef911a"
+checksum = "571575aa3749fa6216757dd47d2a3e7ef360f329a40f0666a9fbd14889024952"
 dependencies = [
  "heck",
  "proc-macro2",
- "pyo3-build-config",
  "quote",
  "syn",
 ]
@@ -3911,7 +3887,7 @@ dependencies = [
  "ntapi",
  "objc2-core-foundation",
  "objc2-io-kit",
- "windows 0.62.2",
+ "windows",
 ]
 
 [[package]]
@@ -4829,9 +4805,9 @@ dependencies = [
  "web-sys",
  "wgpu-naga-bridge",
  "wgpu-types",
- "windows 0.62.2",
- "windows-core 0.62.2",
- "windows-result 0.4.1",
+ "windows",
+ "windows-core",
+ "windows-result",
 ]
 
 [[package]]
@@ -4899,38 +4875,16 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 
-[[package]]
-name = "windows"
-version = "0.61.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9babd3a767a4c1aef6900409f85f5d53ce2544ccdfaa86dad48c91782c6d6893"
-dependencies = [
- "windows-collections 0.2.0",
- "windows-core 0.61.2",
- "windows-future 0.2.1",
- "windows-link 0.1.3",
- "windows-numerics 0.2.0",
-]
-
 [[package]]
 name = "windows"
 version = "0.62.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "527fadee13e0c05939a6a05d5bd6eec6cd2e3dbd648b9f8e447c6518133d8580"
 dependencies = [
- "windows-collections 0.3.2",
- "windows-core 0.62.2",
- "windows-future 0.3.2",
- "windows-numerics 0.3.1",
-]
-
-[[package]]
-name = "windows-collections"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3beeceb5e5cfd9eb1d76b381630e82c4241ccd0d27f1a39ed41b2760b255c5e8"
-dependencies = [
- "windows-core 0.61.2",
+ "windows-collections",
+ "windows-core",
+ "windows-future",
+ "windows-numerics",
 ]
 
 [[package]]
@@ -4939,20 +4893,7 @@ version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "23b2d95af1a8a14a3c7367e1ed4fc9c20e0a26e79551b1454d72583c97cc6610"
 dependencies = [
- "windows-core 0.62.2",
-]
-
-[[package]]
-name = "windows-core"
-version = "0.61.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c0fdd3ddb90610c7638aa2b3a3ab2904fb9e5cdbecc643ddb3647212781c4ae3"
-dependencies = [
- "windows-implement",
- "windows-interface",
- "windows-link 0.1.3",
- "windows-result 0.3.4",
- "windows-strings 0.4.2",
+ "windows-core",
 ]
 
 [[package]]
@@ -4963,20 +4904,9 @@ checksum = "b8e83a14d34d0623b51dce9581199302a221863196a1dde71a7663a4c2be9deb"
 dependencies = [
  "windows-implement",
  "windows-interface",
- "windows-link 0.2.1",
- "windows-result 0.4.1",
- "windows-strings 0.5.1",
-]
-
-[[package]]
-name = "windows-future"
-version = "0.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fc6a41e98427b19fe4b73c550f060b59fa592d7d686537eebf9385621bfbad8e"
-dependencies = [
- "windows-core 0.61.2",
- "windows-link 0.1.3",
- "windows-threading 0.1.0",
+ "windows-link",
+ "windows-result",
+ "windows-strings",
 ]
 
 [[package]]
@@ -4985,9 +4915,9 @@ version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e1d6f90251fe18a279739e78025bd6ddc52a7e22f921070ccdc67dde84c605cb"
 dependencies = [
- "windows-core 0.62.2",
- "windows-link 0.2.1",
- "windows-threading 0.2.1",
+ "windows-core",
+ "windows-link",
+ "windows-threading",
 ]
 
 [[package]]
@@ -5012,45 +4942,20 @@ dependencies = [
  "syn",
 ]
 
-[[package]]
-name = "windows-link"
-version = "0.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5e6ad25900d524eaabdbbb96d20b4311e1e7ae1699af4fb28c17ae66c80d798a"
-
 [[package]]
 name = "windows-link"
 version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f0805222e57f7521d6a62e36fa9163bc891acd422f971defe97d64e70d0a4fe5"
 
-[[package]]
-name = "windows-numerics"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9150af68066c4c5c07ddc0ce30421554771e528bde427614c61038bc2c92c2b1"
-dependencies = [
- "windows-core 0.61.2",
- "windows-link 0.1.3",
-]
-
 [[package]]
 name = "windows-numerics"
 version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6e2e40844ac143cdb44aead537bbf727de9b044e107a0f1220392177d15b0f26"
 dependencies = [
- "windows-core 0.62.2",
- "windows-link 0.2.1",
-]
-
-[[package]]
-name = "windows-result"
-version = "0.3.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "56f42bd332cc6c8eac5af113fc0c1fd6a8fd2aa08a0119358686e5160d0586c6"
-dependencies = [
- "windows-link 0.1.3",
+ "windows-core",
+ "windows-link",
 ]
 
 [[package]]
@@ -5059,16 +4964,7 @@ version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7781fa89eaf60850ac3d2da7af8e5242a5ea78d1a11c49bf2910bb5a73853eb5"
 dependencies = [
- "windows-link 0.2.1",
-]
-
-[[package]]
-name = "windows-strings"
-version = "0.4.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "56e6c93f3a0c3b36176cb1327a4958a0353d5d166c2a35cb268ace15e91d3b57"
-dependencies = [
- "windows-link 0.1.3",
+ "windows-link",
 ]
 
 [[package]]
@@ -5077,7 +4973,7 @@ version = "0.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7837d08f69c77cf6b07689544538e017c1bfcf57e34b4c0ff58e6c2cd3b37091"
 dependencies = [
- "windows-link 0.2.1",
+ "windows-link",
 ]
 
 [[package]]
@@ -5113,7 +5009,7 @@ version = "0.61.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ae137229bcbd6cdf0f7b80a31df61766145077ddf49416a728b02cb3921ff3fc"
 dependencies = [
- "windows-link 0.2.1",
+ "windows-link",
 ]
 
 [[package]]
@@ -5138,7 +5034,7 @@ version = "0.53.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4945f9f551b88e0d65f3db0bc25c33b8acea4d9e41163edf90dcd0b19f9069f3"
 dependencies = [
- "windows-link 0.2.1",
+ "windows-link",
  "windows_aarch64_gnullvm 0.53.1",
  "windows_aarch64_msvc 0.53.1",
  "windows_i686_gnu 0.53.1",
@@ -5149,22 +5045,13 @@ dependencies = [
  "windows_x86_64_msvc 0.53.1",
 ]
 
-[[package]]
-name = "windows-threading"
-version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b66463ad2e0ea3bbf808b7f1d371311c80e115c0b71d60efc142cafbcfb057a6"
-dependencies = [
- "windows-link 0.1.3",
-]
-
 [[package]]
 name = "windows-threading"
 version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3949bd5b99cafdf1c7ca86b43ca564028dfe27d66958f2470940f73d86d75b37"
 dependencies = [
- "windows-link 0.2.1",
+ "windows-link",
 ]
 
 [[package]]
diff --git a/crates/symclaw-python/Cargo.toml b/crates/symclaw-python/Cargo.toml
index 730d946..b5efc6b 100644
--- a/crates/symclaw-python/Cargo.toml
+++ b/crates/symclaw-python/Cargo.toml
@@ -14,6 +14,6 @@ crate-type = ["cdylib"]
 
 [dependencies]
 symclaw-core = { path = "../symclaw-core" }
-pyo3 = { version = "0.24", features = ["extension-module"] }
+pyo3 = { version = "0.29", features = ["extension-module"] }
 num-rational = { workspace = true }
 ordered-float = { workspace = true }
diff --git a/crates/symclaw-python/src/lib.rs b/crates/symclaw-python/src/lib.rs
index 5d82126..0aa0c3e 100644
--- a/crates/symclaw-python/src/lib.rs
+++ b/crates/symclaw-python/src/lib.rs
@@ -163,7 +163,7 @@ fn py_to_expr(obj: &Bound<'_, PyAny>) -> PyResult<Arc<Expr>> {
 // ── PyExpr ───────────────────────────────────────────────────────
 
 /// A Python-facing symbolic expression.
-#[pyclass(name = "Expression")]
+#[pyclass(name = "Expression", from_py_object)]
 #[derive(Clone)]
 struct PyExpr {
     inner: Arc<Expr>,
@@ -482,7 +482,7 @@ impl PyLimitResult {
 /// Create symbol(s). Single name returns Expression, comma-separated returns tuple.
 #[pyfunction]
 #[pyo3(name = "S")]
-fn py_s(py: Python<'_>, names: &str) -> PyResult<PyObject> {
+fn py_s(py: Python<'_>, names: &str) -> PyResult<Py<PyAny>> {
     let parts: Vec<&str> = names
         .split(',')
         .map(str::trim)