diff --git a/.miserc.toml b/.miserc.toml
deleted file mode 100644
index 8f0b74b..0000000
--- a/.miserc.toml
+++ /dev/null
@@ -1 +0,0 @@
-auto_env = true
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 021776b..97fa313 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -49,8 +49,8 @@ needs a version, which would override `rust-toolchain.toml` (the sole owner of t
 So plain `cargo` is not routed through `mbx`; call `mbx` explicitly. Set
 `CARGO_INCREMENTAL=0` for the best hit rate.
 
-There is no prebuilt `mbx` for Intel macOS, so `mise.macos-x64.toml` (loaded through `auto_env` in
-`.miserc.toml`) builds it from crates.io via the `cargo:mbx` backend (Rust 1.91 or newer). Without
+There is no prebuilt `mbx` for Intel macOS, so `mise.toml` limits `mr-boxington` to the other
+platforms and builds `mbx` there from crates.io via the `cargo:mbx` backend (Rust 1.91 or newer). Without
 mise, run `cargo install mbx --version 1.29.2 --locked`.
 
 `mbx` wraps `rustc` itself, so it **defers to any `RUSTC_WRAPPER` already set** (for example
diff --git a/mise.lock b/mise.lock
index fe1e8f2..6487cc9 100644
--- a/mise.lock
+++ b/mise.lock
@@ -56,6 +56,11 @@ version = "1.48.0"
 backend = "cargo:hk"
 specifiers = ["1.48.0"]
 
+[[tools."cargo:mbx"]]
+version = "1.29.2"
+backend = "cargo:mbx"
+specifiers = ["1.29.2"]
+
 [[tools.mr-boxington]]
 version = "1.29.2"
 backend = "packslip:github.com/jdx/mr-boxington"
@@ -79,12 +84,24 @@ url = "https://github.com/jdx/mr-boxington/releases/download/v1.29.2/mbx-x86_64-
 signer = "sigstore-oidc:https://github.com/jdx/mr-boxington/.github/workflows/release.yml"
 repository_ids = { repository = "1340721957" }
 
+[tools.mr-boxington."platforms.linux-x64-baseline"]
+checksum = "sha256:73e135d3e9e8b8ddc938b42407179a239917b7f02d3fa5f601f6783e5c0d36d6"
+url = "https://github.com/jdx/mr-boxington/releases/download/v1.29.2/mbx-x86_64-unknown-linux-gnu.tar.gz"
+signer = "sigstore-oidc:https://github.com/jdx/mr-boxington/.github/workflows/release.yml"
+repository_ids = { repository = "1340721957" }
+
 [tools.mr-boxington."platforms.linux-x64-musl"]
 checksum = "sha256:60be3ffbb4d71418827ed28686c776b86bdbb804edd43739b1dbfcdf162fbcb5"
 url = "https://github.com/jdx/mr-boxington/releases/download/v1.29.2/mbx-x86_64-unknown-linux-musl.tar.gz"
 signer = "sigstore-oidc:https://github.com/jdx/mr-boxington/.github/workflows/release.yml"
 repository_ids = { repository = "1340721957" }
 
+[tools.mr-boxington."platforms.linux-x64-musl-baseline"]
+checksum = "sha256:60be3ffbb4d71418827ed28686c776b86bdbb804edd43739b1dbfcdf162fbcb5"
+url = "https://github.com/jdx/mr-boxington/releases/download/v1.29.2/mbx-x86_64-unknown-linux-musl.tar.gz"
+signer = "sigstore-oidc:https://github.com/jdx/mr-boxington/.github/workflows/release.yml"
+repository_ids = { repository = "1340721957" }
+
 [tools.mr-boxington."platforms.macos-arm64"]
 checksum = "sha256:621ce235d8f241c5a3728ca03d34b9864f466f4e8b3307d8a6d7101a24a71a60"
 url = "https://github.com/jdx/mr-boxington/releases/download/v1.29.2/mbx-aarch64-apple-darwin.tar.gz"
@@ -97,6 +114,12 @@ url = "https://github.com/jdx/mr-boxington/releases/download/v1.29.2/mbx-x86_64-
 signer = "sigstore-oidc:https://github.com/jdx/mr-boxington/.github/workflows/release.yml"
 repository_ids = { repository = "1340721957" }
 
+[tools.mr-boxington."platforms.windows-x64-baseline"]
+checksum = "sha256:5ccfe5942c224844ffc50eb689de9c02033e401b210d3c80fffe4b94c929b0a2"
+url = "https://github.com/jdx/mr-boxington/releases/download/v1.29.2/mbx-x86_64-pc-windows-msvc.zip"
+signer = "sigstore-oidc:https://github.com/jdx/mr-boxington/.github/workflows/release.yml"
+repository_ids = { repository = "1340721957" }
+
 [[tools.node]]
 version = "24.22.2"
 backend = "core:node"
diff --git a/mise.macos-x64.lock b/mise.macos-x64.lock
deleted file mode 100644
index 063a85f..0000000
--- a/mise.macos-x64.lock
+++ /dev/null
@@ -1,8 +0,0 @@
-# @generated - this file is auto-generated by `mise lock` https://mise.jdx.dev/dev-tools/mise-lock.html
-
-lockfile_version = 4
-
-[[tools.mr-boxington]]
-version = "1.29.2"
-backend = "cargo:mbx"
-specifiers = ["1.29.2"]
diff --git a/mise.macos-x64.toml b/mise.macos-x64.toml
deleted file mode 100644
index 4b81b4b..0000000
--- a/mise.macos-x64.toml
+++ /dev/null
@@ -1,6 +0,0 @@
-# mr-boxington ships no darwin/x86_64 release archive, so build mbx from crates.io.
-[tools]
-mr-boxington = "1.29.2"
-
-[tool_alias]
-mr-boxington = "cargo:mbx"
diff --git a/mise.toml b/mise.toml
index e514889..3d22cc5 100644
--- a/mise.toml
+++ b/mise.toml
@@ -11,6 +11,9 @@
 # mise.lock is lockfile_version 4, which mise 2026.11.1+ writes and reads.
 min_version = "2026.11.1"
 
+[vars]
+mbx = "1.29.2"
+
 [tools]
 node = "24"
 bun = "1.3.14" # matches package.json packageManager
@@ -20,7 +23,18 @@ bun = "1.3.14" # matches package.json packageManager
 # Pinned to match the v1.48.0 hk.pkl amends — keep the two in sync on upgrades.
 # Details: dev-tooling → references/git-hooks.md
 "cargo:hk" = "1.48.0"
-mr-boxington = "1.29.2"
+
+# mr-boxington ships no darwin/x86_64 release archive, so Intel macOS builds the same mbx
+# from crates.io.
+mr-boxington.version = "{{vars.mbx}}"
+mr-boxington.os = [
+  "linux",
+  "macos/arm64",
+  "windows",
+]
+
+"cargo:mbx".version = "{{vars.mbx}}"
+"cargo:mbx".os = [ "macos/x64" ]
 
 [env]
 # Wrap hooks in `mise x` so the mise-managed node/bun are on PATH
@@ -34,14 +48,6 @@ HK_MISE = "1"
 # to avoid a noisy "hk: not found" postinstall warning where git hooks aren't wanted.
 postinstall = "command -v hk >/dev/null 2>&1 && hk install --mise || true"
 
-[tasks.lock]
-description = "Refresh mise.lock checksums without the macos-x64 cargo:mbx alias"
-env = { MISE_AUTO_ENV = "false" }
-run = [
-  "mise lock node bun cargo:hk",
-  "mise lock mr-boxington --platform linux-x64,linux-arm64,linux-x64-musl,linux-arm64-musl,macos-arm64,windows-x64"
-]
-
 [tasks.lint]
 description = "Lint JS/TS (eslint)"
 run = "bun run lint"