diff --git a/Makefile b/Makefile
index d7e2a73a..eab71919 100644
--- a/Makefile
+++ b/Makefile
@@ -1,29 +1,5 @@
-UNAME := $(shell uname)
-
-ifeq ($(UNAME), Darwin)
-    OS_MESSAGE := "MacOS detected"
-	CMAKE_SETUP := "which cmake || brew install cmake"
-	PROTOBUF_SETUP := "which protoc || brew install protobuf"
-	OPENSSL_SETUP := "which openssl || brew install openssl"
-else ifeq ($(UNAME), Linux)
-	OS_MESSAGE := "Linux detected"
-	CMAKE_SETUP := "which cmake || sudo apt-get install --yes build-essential cmake"
-	PROTOBUF_SETUP := "which protoc || sudo apt-get install --yes protobuf-compiler"
-	OPENSSL_SETUP := "which openssl || sudo apt-get install --yes libssl-dev"
-else
-	OS_MESSAGE := "Unsupported OS; please install rust, cmake, protobuf, and openssl manually"
-	CMAKE_SETUP := ""
-	PROTOBUF_SETUP := ""
-	OPENSSL_SETUP := ""
-endif
-
 setup:
-	@echo "${OS_MESSAGE}: installing..."
-	$(shell "${CMAKE_SETUP}")
-	$(shell "${PROTOBUF_SETUP}")
-	$(shell "${OPENSSL_SETUP}")
-	which cargo || curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
-	which maturin || pip install maturin[patchelf]
+	@./setup.sh
 
 publish:
 	maturin publish
diff --git a/docs/mixer.md b/docs/mixer.md
index afa49fd6..6a20add0 100644
--- a/docs/mixer.md
+++ b/docs/mixer.md
@@ -25,7 +25,7 @@ The following parameters are supported either via CLI (e.g. `dolma mix --paramet
 |`streams[].span_replacement`|No| A list of objects specifying spans of text to be replaced. |
 |`streams[].span_replacement[].span`|No| A json-path expression for an attribute that contains an array of spans. Each span should be list of length three:  `[start, end, score]`. |
 |`streams[].span_replacement[].min_score`|No| If the span score is less than this value, the span will not be replaced. |
-|`streams[].span_replacement[].replacement`|No| The text that should be inserted in place of the span. Use `{}` to represent the original text. |
+|`streams[].span_replacement[].replacement`|No| The text that should be inserted in place of the span. Use `{}` to represent the original text. Field selection from the document is also supported by prefixing a jq selector with `$`. Note: Escape a leading $ if you do not with to use jq selector pattern. |
 |`work_dir.input`|No| Path to a local scratch directory where temporary input files can be placed. If not provided, Dolma will make one for you and delete it upon completion. |
 |`work_dir.output`|No| Path to a local scratch directory where temporary output files can be placed. If not provided, Dolma will make one for you and delete it upon completion. |
 |`processes`|No| Number of processes to use for mixing. By default 1 process is used. |
diff --git a/pyproject.toml b/pyproject.toml
index 13ff1ff7..cc48c430 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "dolma"
-version = "1.0.12"
+version = "1.0.13"
 description = "Data filters"
 license = { text = "Apache-2.0" }
 readme = "README.md"
diff --git a/python/dolma/cli/mixer.py b/python/dolma/cli/mixer.py
index 8be8a0d9..943d7f74 100644
--- a/python/dolma/cli/mixer.py
+++ b/python/dolma/cli/mixer.py
@@ -40,7 +40,7 @@ class SpanReplacementConfig:
         default=None,
         help="Maximum score for the span to be replaced. Either min_score or max_score must be specified.",
     )
-    replacement: str = field(default="", help="Replacement for the span")
+    replacement: str = field(default="", help="Replacement config for the span(s).")
     syntax: str = field(
         default="jsonpath",
         help="Syntax to use for filter expressions. Currently only JSONPath is supported. Defaults to JSONPath.",
diff --git a/setup.sh b/setup.sh
new file mode 100755
index 00000000..0b4212a7
--- /dev/null
+++ b/setup.sh
@@ -0,0 +1,40 @@
+#!/bin/bash
+set -e
+
+UNAME="$(uname)"
+PLATFORM="$(uname -m)"
+
+if [[ $UNAME == "Darwin" ]]; then
+  echo "MacOS detected..."
+  which cmake || brew install cmake
+  which protoc || brew install protobuf
+  which openssl || brew install openssl
+elif [[ $UNAME == "Linux" ]]; then
+  echo "Linux detected..."
+  which cmake || sudo apt-get install --yes build-essential cmake
+  which protoc || sudo apt-get install --yes protobuf-compiler
+  which openssl || sudo apt-get install --yes libssl-dev
+else
+  echo "Unsupported OS; please install rust, cmake, protobuf, maturin and openssl manually!"
+  exit 1
+fi
+
+which cargo || curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
+
+if [[ $PLATFORM == "x86_64" ]]; then
+  echo "x86_64 detected..."
+  which maturin || pip install maturin[patchelf]
+fi
+
+if [[ $PLATFORM = "aarch64" ]]; then
+  echo "aarch64 detected..."
+  which maturin || pip install maturin
+fi
+
+if [[ $PLATFORM = arm* ]]; then
+  echo "arm detected..."
+  which maturin || pip install maturin
+else
+  echo "Unsupported platform; please install maturin manually"
+  exit 0
+fi
diff --git a/src/shard.rs b/src/shard.rs
index 526f4f4f..d5992caa 100644
--- a/src/shard.rs
+++ b/src/shard.rs
@@ -399,9 +399,10 @@ impl Shard {
                                     );
                                 new_text.push_str(&replacement_text);
                             }
+
                             data["text"] = Value::String(new_text);
                         }
-                        // }
+
                         for f in self.discard_fields.iter().flatten() {
                             data.as_object_mut().unwrap().remove(f);
                         }
@@ -467,7 +468,7 @@ impl Shard {
 }
 
 pub mod shard_config {
-    use crate::filters::Selector;
+    use crate::filters::{JqSelector, Selector};
     use jsonpath_rust::JsonPathFinder;
     use serde::{Deserialize, Serialize};
     use serde_json::Value;
@@ -543,7 +544,34 @@ pub mod shard_config {
         selector: Selector,
         min_score: f64,
         max_score: f64,
-        replacement: String,
+        replacement: Replacement,
+    }
+
+    pub enum Replacement {
+        Selectors(JqSelector),
+        String(String),
+    }
+
+    impl Replacement {
+        pub fn new(string: &str) -> Result<Replacement, IoError> {
+            // Note: Users should escape leading $ in replacement strings
+            if string.starts_with("$") {
+                // Strip leading $ and create a selector
+                let selector = JqSelector::new(&string[1..])?;
+                Ok(Replacement::Selectors(selector))
+            } else {
+                Ok(Replacement::String(string.to_string()))
+            }
+        }
+
+        pub fn get(&self, json: &Value) -> Result<String, IoError> {
+            match self {
+                Replacement::Selectors(selector) => {
+                    Ok(serde_json::from_value(selector.select(json)?.to_owned()).unwrap())
+                }
+                Replacement::String(s) => Ok(s.clone()),
+            }
+        }
     }
 
     impl SpanReplacer {
@@ -553,7 +581,7 @@ pub mod shard_config {
                 selector: Selector::new(&config).unwrap(),
                 min_score: config.min_score.unwrap_or(f64::NEG_INFINITY),
                 max_score: config.max_score.unwrap_or(f64::INFINITY),
-                replacement: config.replacement.clone(),
+                replacement: Replacement::new(&config.replacement).unwrap(),
             }
         }
 
@@ -575,7 +603,7 @@ pub mod shard_config {
                                 let replacement = SpanReplacement {
                                     start: start as usize,
                                     end: end as usize,
-                                    replacement: self.replacement.clone(),
+                                    replacement: self.replacement.get(json).unwrap(),
                                 };
                                 Some(replacement)
                             } else {