diff --git a/ci/OWNERS b/ci/OWNERS
index 6e2ba2f601ae..2492a221a7c8 100644
--- a/ci/OWNERS
+++ b/ci/OWNERS
@@ -73,6 +73,7 @@
 
 ## Format generators/serializers
 /pkgs/pkgs-lib                                   @Stunkymonkey @h7x4
+/pkgs/pkgs-lib/formats/json2x                    @Stunkymonkey @h7x4 @figsoda
 
 # Nixpkgs build-support
 /pkgs/build-support/writers @lassulus
diff --git a/pkgs/pkgs-lib/formats.nix b/pkgs/pkgs-lib/formats.nix
index cfe95417ac31..afeed91669bf 100644
--- a/pkgs/pkgs-lib/formats.nix
+++ b/pkgs/pkgs-lib/formats.nix
@@ -81,6 +81,8 @@ let
       str
       ;
   };
+
+  json2x = pkgs.callPackage ./formats/json2x/package.nix { };
 in
 optionalAttrs allowAliases aliases
 // rec {
@@ -469,7 +471,7 @@ optionalAttrs allowAliases aliases
           { runCommand, remarshal }:
           runCommand name
             {
-              nativeBuildInputs = [ remarshal ];
+              nativeBuildInputs = [ json2x ];
               value = builtins.toJSON value;
               preferLocalBuild = true;
               __structuredAttrs = true;
@@ -477,7 +479,7 @@ optionalAttrs allowAliases aliases
             ''
               valuePath="$TMPDIR/value"
               printf "%s" "$value" > "$valuePath"
-              json2toml "$valuePath" "$out"
+              json2x toml "$valuePath" "$out"
             ''
         ) { };
 
diff --git a/pkgs/pkgs-lib/formats/json2x/.gitignore b/pkgs/pkgs-lib/formats/json2x/.gitignore
new file mode 100644
index 000000000000..ea8c4bf7f35f
--- /dev/null
+++ b/pkgs/pkgs-lib/formats/json2x/.gitignore
@@ -0,0 +1 @@
+/target
diff --git a/pkgs/pkgs-lib/formats/json2x/Cargo.lock b/pkgs/pkgs-lib/formats/json2x/Cargo.lock
new file mode 100644
index 000000000000..7a7f2447dbf0
--- /dev/null
+++ b/pkgs/pkgs-lib/formats/json2x/Cargo.lock
@@ -0,0 +1,221 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "anyhow"
+version = "1.0.102"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f202df86484c868dbad7eaa557ef785d5c66295e41b460ef922eca0723b842c"
+
+[[package]]
+name = "argh"
+version = "0.1.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "211818e820cda9ca6f167a64a5c808837366a6dfd807157c64c1304c486cd033"
+dependencies = [
+ "argh_derive",
+ "argh_shared",
+]
+
+[[package]]
+name = "argh_derive"
+version = "0.1.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c442a9d18cef5dde467405d27d461d080d68972d6d0dfd0408265b6749ec427d"
+dependencies = [
+ "argh_shared",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "argh_shared"
+version = "0.1.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e5ade012bac4db278517a0132c8c10c6427025868dca16c801087c28d5a411f1"
+dependencies = [
+ "serde",
+]
+
+[[package]]
+name = "equivalent"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
+
+[[package]]
+name = "hashbrown"
+version = "0.17.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed5909b6e89a2db4456e54cd5f673791d7eca6732202bbf2a9cc504fe2f9b84a"
+
+[[package]]
+name = "indexmap"
+version = "2.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d466e9454f08e4a911e14806c24e16fba1b4c121d1ea474396f396069cf949d9"
+dependencies = [
+ "equivalent",
+ "hashbrown",
+]
+
+[[package]]
+name = "itoa"
+version = "1.0.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f42a60cbdf9a97f5d2305f08a87dc4e09308d1276d28c869c684d7777685682"
+
+[[package]]
+name = "json2x"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "argh",
+ "serde_json",
+ "toml",
+]
+
+[[package]]
+name = "memchr"
+version = "2.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f8ca58f447f06ed17d5fc4043ce1b10dd205e060fb3ce5b979b8ed8e59ff3f79"
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.106"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8fd00f0bb2e90d81d1044c2b32617f68fcb9fa3bb7640c23e9c748e53fb30934"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.45"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41f2619966050689382d2b44f664f4bc593e129785a36d6ee376ddf37259b924"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "serde"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a8e94ea7f378bd32cbbd37198a4a91436180c5bb472411e48b5ec2e2124ae9e"
+dependencies = [
+ "serde_core",
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_core"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41d385c7d4ca58e59fc732af25c3983b67ac852c1a25000afe1175de458b67ad"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d540f220d3187173da220f885ab66608367b6574e925011a9353e4badda91d79"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "serde_json"
+version = "1.0.149"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "83fc039473c5595ace860d8c4fafa220ff474b3fc6bfdb4293327f1a37e94d86"
+dependencies = [
+ "itoa",
+ "memchr",
+ "serde",
+ "serde_core",
+ "zmij",
+]
+
+[[package]]
+name = "serde_spanned"
+version = "1.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6662b5879511e06e8999a8a235d848113e942c9124f211511b16466ee2995f26"
+dependencies = [
+ "serde_core",
+]
+
+[[package]]
+name = "syn"
+version = "2.0.117"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e665b8803e7b1d2a727f4023456bbbbe74da67099c585258af0ad9c5013b9b99"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "toml"
+version = "1.1.2+spec-1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "81f3d15e84cbcd896376e6730314d59fb5a87f31e4b038454184435cd57defee"
+dependencies = [
+ "indexmap",
+ "serde_core",
+ "serde_spanned",
+ "toml_datetime",
+ "toml_parser",
+ "toml_writer",
+]
+
+[[package]]
+name = "toml_datetime"
+version = "1.1.1+spec-1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3165f65f62e28e0115a00b2ebdd37eb6f3b641855f9d636d3cd4103767159ad7"
+dependencies = [
+ "serde_core",
+]
+
+[[package]]
+name = "toml_parser"
+version = "1.1.2+spec-1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a2abe9b86193656635d2411dc43050282ca48aa31c2451210f4202550afb7526"
+dependencies = [
+ "winnow",
+]
+
+[[package]]
+name = "toml_writer"
+version = "1.1.1+spec-1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "756daf9b1013ebe47a8776667b466417e2d4c5679d441c26230efd9ef78692db"
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
+
+[[package]]
+name = "winnow"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0592e1c9d151f854e6fd382574c3a0855250e1d9b2f99d9281c6e6391af352f1"
+
+[[package]]
+name = "zmij"
+version = "1.0.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8848ee67ecc8aedbaf3e4122217aff892639231befc6a1b58d29fff4c2cabaa"
diff --git a/pkgs/pkgs-lib/formats/json2x/Cargo.toml b/pkgs/pkgs-lib/formats/json2x/Cargo.toml
new file mode 100644
index 000000000000..84df52533b68
--- /dev/null
+++ b/pkgs/pkgs-lib/formats/json2x/Cargo.toml
@@ -0,0 +1,20 @@
+[package]
+name = "json2x"
+version = "0.1.0"
+edition = "2024"
+publish = false
+
+[dependencies]
+anyhow = "1.0.102"
+argh = "0.1.19"
+serde_json = "1.0.149"
+
+[dependencies.toml]
+version = "1.1.2"
+default-features = false
+features = ["display", "serde", "std"]
+
+[profile.release]
+lto = true
+panic = "abort"
+codegen-units = 1
diff --git a/pkgs/pkgs-lib/formats/json2x/package.nix b/pkgs/pkgs-lib/formats/json2x/package.nix
new file mode 100644
index 000000000000..fcafe0b57f03
--- /dev/null
+++ b/pkgs/pkgs-lib/formats/json2x/package.nix
@@ -0,0 +1,19 @@
+{
+  lib,
+  rustPlatform,
+}:
+
+rustPlatform.buildRustPackage {
+  pname = "json2x";
+  version = "0.1.0";
+  __structuredAttrs = true;
+
+  src = lib.sourceByRegex ./. [
+    "^src(/.*)?$"
+    ''^Cargo\.(lock|toml)$''
+  ];
+
+  cargoLock = {
+    lockFile = ./Cargo.lock;
+  };
+}
diff --git a/pkgs/pkgs-lib/formats/json2x/src/main.rs b/pkgs/pkgs-lib/formats/json2x/src/main.rs
new file mode 100644
index 000000000000..b9025c67f42a
--- /dev/null
+++ b/pkgs/pkgs-lib/formats/json2x/src/main.rs
@@ -0,0 +1,49 @@
+use std::{
+    fs::{File, read_to_string},
+    io::Write,
+    path::PathBuf,
+};
+
+use anyhow::Context;
+use argh::{FromArgValue, FromArgs};
+
+/// Convert a JSON file to another format
+#[derive(FromArgs)]
+struct Args {
+    /// format of the output file, possible values: toml
+    #[argh(positional)]
+    format: Format,
+    /// path to the input file
+    #[argh(positional)]
+    input: PathBuf,
+    /// path to the output file
+    #[argh(positional)]
+    output: PathBuf,
+}
+
+#[derive(FromArgValue)]
+enum Format {
+    Toml,
+}
+
+fn main() -> anyhow::Result<()> {
+    let args: Args = argh::from_env();
+
+    let input = read_to_string(&args.input)
+        .with_context(|| format!("failed to read {}", args.input.display()))?;
+    let input: serde_json::Value = serde_json::from_str(&input)
+        .with_context(|| format!("failed to parse {}", args.input.display()))?;
+    let mut output = File::create(&args.output)
+        .with_context(|| format!("failed to create {}", args.output.display()))?;
+
+    match args.format {
+        Format::Toml => {
+            let content = toml::to_string(&input).context("failed to serialize value to toml")?;
+            output
+                .write_all(content.as_bytes())
+                .with_context(|| format!("failed to write to {}", args.output.display()))?;
+        }
+    }
+
+    Ok(())
+}
diff --git a/pkgs/pkgs-lib/tests/formats.nix b/pkgs/pkgs-lib/tests/formats.nix
index f1da9041ea79..7e3f6457588f 100644
--- a/pkgs/pkgs-lib/tests/formats.nix
+++ b/pkgs/pkgs-lib/tests/formats.nix
@@ -723,7 +723,7 @@ runBuildTests {
       ];
     };
     expected = ''
-      language-server = ["bash-language-server", {except-features = ["diagnostics"], name = "typescript-language-server"}]
+      language-server = ["bash-language-server", { except-features = ["diagnostics"], name = "typescript-language-server" }]
     '';
   };