diff --git a/server/Cargo.lock b/server/Cargo.lock
index b650552..7e94b15 100644
--- a/server/Cargo.lock
+++ b/server/Cargo.lock
@@ -2,18 +2,78 @@
 # It is not intended for manual editing.
 version = 4
 
+[[package]]
+name = "block-buffer"
+version = "0.10.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3078c7629b62d3f0439517fa394996acacc5cbc91c5a20d8c658e77abd503a71"
+dependencies = [
+ "generic-array",
+]
+
+[[package]]
+name = "cfg-if"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
+
+[[package]]
+name = "cpufeatures"
+version = "0.2.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "59ed5838eebb26a2bb2e58f6d5b5316989ae9d08bab10e0e6d103e656d1b0280"
+dependencies = [
+ "libc",
+]
+
+[[package]]
+name = "crypto-common"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "78c8292055d1c1df0cce5d180393dc8cce0abec0a7102adb6c7b1eef6016d60a"
+dependencies = [
+ "generic-array",
+ "typenum",
+]
+
+[[package]]
+name = "digest"
+version = "0.10.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9ed9a281f7bc9b7576e61468ba615a66a5c8cfdff42420a70aa82701a3b1e292"
+dependencies = [
+ "block-buffer",
+ "crypto-common",
+]
+
 [[package]]
 name = "equivalent"
 version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
 
+[[package]]
+name = "generic-array"
+version = "0.14.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85649ca51fd72272d7821adaf274ad91c288277713d9c18820d8499a7ff69e9a"
+dependencies = [
+ "typenum",
+ "version_check",
+]
+
 [[package]]
 name = "hashbrown"
 version = "0.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5419bdc4f6a9207fbeba6d11b604d481addf78ecd10c11ad51e76c2f6482748d"
 
+[[package]]
+name = "hex"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"
+
 [[package]]
 name = "indexmap"
 version = "2.12.0"
@@ -30,6 +90,12 @@ version = "1.0.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4a5f13b858c8d314ee3e8f639011f7ccefe71f97f96e50151fb991f267928e2c"
 
+[[package]]
+name = "libc"
+version = "0.2.178"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "37c93d8daa9d8a012fd8ab92f088405fb202ea0b6ab73ee2482ae66af4f42091"
+
 [[package]]
 name = "memchr"
 version = "2.7.6"
@@ -112,6 +178,17 @@ dependencies = [
  "serde_core",
 ]
 
+[[package]]
+name = "sha2"
+version = "0.10.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a7507d819769d01a365ab707794a4084392c824f54a7a6a7862f8c3d0892b283"
+dependencies = [
+ "cfg-if",
+ "cpufeatures",
+ "digest",
+]
+
 [[package]]
 name = "syn"
 version = "2.0.110"
@@ -162,18 +239,32 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "df8b2b54733674ad286d16267dcfc7a71ed5c776e4ac7aa3c3e2561f7c637bf2"
 
+[[package]]
+name = "typenum"
+version = "1.19.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "562d481066bde0658276a35467c4af00bdc6ee726305698a55b86e61d7ad82bb"
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9312f7c4f6ff9069b165498234ce8be658059c6728633667c526e27dc2cf1df5"
 
+[[package]]
+name = "version_check"
+version = "0.9.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
+
 [[package]]
 name = "wgu"
 version = "0.0.1"
 dependencies = [
+ "hex",
  "serde",
  "serde_json",
+ "sha2",
  "toml",
 ]
 
diff --git a/server/Cargo.toml b/server/Cargo.toml
index 9ef1a1f..c6307df 100644
--- a/server/Cargo.toml
+++ b/server/Cargo.toml
@@ -5,6 +5,8 @@ version = "0.0.1"
 edition = "2024"
 
 [dependencies]
+hex = "0.4.3"
 serde = { version = "*", features = ["derive"] }
 serde_json = "1.0.145"
+sha2 = "0.10.9"
 toml = "0.9.8"
diff --git a/server/src/lib.rs b/server/src/lib.rs
index a06d9a2..9bc8443 100644
--- a/server/src/lib.rs
+++ b/server/src/lib.rs
@@ -1,10 +1,15 @@
 pub mod modules;
 pub mod types;
 
-use crate::modules::{ModuleItem, item_registry};
-use crate::types::{ObjectInstance, ObjectTemplate};
+use std::time::{SystemTime, UNIX_EPOCH};
+use std::collections::HashMap;
+
+use crate::modules::{ModuleItem, FunctionItem, item_registry};
+use crate::types::{FunctionTemplate, FunctionTemplateObject, ObjectInstance, ObjectTemplate};
 
 use serde_json::{Value, json};
+use sha2::{Sha256, Digest};
+use hex;
 
 impl ObjectTemplate {
     fn from_object_type(object_type: &str) -> Result<ObjectTemplate, String> {
@@ -21,13 +26,50 @@ impl ObjectTemplate {
 }
 
 impl ObjectInstance {
-    pub fn from_template(object_type: &str, input: Value) -> Result<Self, String> {
-        let instance = ObjectInstance {
+    pub fn from_object_type(object_type: &str, input: Value) -> Result<Self, String> {
+        let mut instance = ObjectInstance {
             object_type: object_type.to_string(),
             input: json!(input),
             ..ObjectInstance::default()
         };
 
+        // https://stackoverflow.com/questions/26593387/how-can-i-get-the-current-time-in-milliseconds
+        instance.created = format!("{:?}", SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .expect("time should go forward")
+            .as_millis());
+
+        instance.edited = format!("{:?}", SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .expect("time should go forward")
+            .as_millis());
+
+        instance.hashed = format!("{:?}", SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .expect("time should go forward")
+            .as_millis());
+
+        let input_sha256_bytes = Sha256::digest(
+            format!("{}+{}",
+                instance.object_type,
+                json!(instance.input)
+            )
+        );
+
+        instance.input_sha256 = hex::encode(input_sha256_bytes);
+
+        let full_sha256_bytes = Sha256::digest(
+            format!("{}+{}+{}+{}+{}",
+                instance.object_type,
+                instance.hashed,
+                json!(instance.input),
+                json!(instance.local),
+                json!(instance.remote)
+            )
+        );
+        
+        instance.full_sha256 = hex::encode(full_sha256_bytes);
+
         ObjectInstance::validate(&instance)?;
         Ok(instance)
     }
@@ -66,7 +108,13 @@ impl ObjectInstance {
         Ok(())
     }
 
-    pub fn transform(obj: &ObjectInstance, source: &str, destination: &str) -> Result<Self, String> {
+    pub fn run_transform(
+        obj: &ObjectInstance,
+        source: &str,
+        destination: &str
+    )
+        -> Result<Self, String>
+    {
         let object_type = &obj.object_type;
         let template = ObjectTemplate::from_object_type(object_type)?;
         
@@ -100,13 +148,75 @@ impl ObjectInstance {
         };
 
         if template_property.transforms.contains(&destination.to_string()) {
-            let result = ObjectInstance::from_template(destination_parts[0], json!({
+            let result = ObjectInstance::from_object_type(destination_parts[0], json!({
                 destination_parts[1]: source_instance_category.get(source_parts[1])
             }))?;
 
             Ok(result)
         } else {
-            Err(format!("invalid transform destination {}", destination))
+            Err(format!("invalid destination {}", destination))
         }
     }
+
+    pub fn run_function(
+        function: &str,
+        inputs: FunctionItem,
+        params: Option<FunctionItem>
+    )
+        -> Result<FunctionItem, String> 
+    {
+        let modules = item_registry();
+ 
+        // same thing as in ObjectTemplate::from_object_type
+        let (template, function): (FunctionTemplate, _) = match modules.get(function) {
+            Some(ModuleItem::Function((template_str, function))) => (toml::from_str(template_str).unwrap(), function),
+            Some(_) => return Err(format!("the ModuleItem `{}` is not a ModuleItem::Function", function)),
+            None => return Err(format!("the ModuleItem `{}` doesn't exist", function))
+        };
+
+        validate_function_data(&inputs, &template.inputs, "input")?;
+
+        if let Some(params) = &params {
+            validate_function_data(params, &template.params, "parameter")?;
+        }
+ 
+        let result = function(inputs.clone(), params.clone())?;
+        validate_function_data(&result, &template.outputs, "output")?;
+
+        Ok(result)
+    }
+}
+
+// helpers
+
+fn validate_function_data(data: &FunctionItem, template: &HashMap<String, FunctionTemplateObject>, category: &str) -> Result<(), String> {
+    for (name, template_object) in template {
+        if let None = data.get(name) && template_object.required {
+            return Err(format!("required {} {} doesn't exist", category, name))
+        }
+    }
+
+    for (name, instances) in data {
+        let template_object = match template.get(name) {
+            Some(template_object) => template_object,
+            None => return Err(format!("{} {} doesn't exist in the template", "input", name))
+        };
+
+        let expected_count = &template_object.count;
+        let expected_object_type = &template_object.object_type;
+
+        if instances.len() != *expected_count {
+            return Err(format!("the amount of object instances in the {} {} ({}) doesn't match the expected amount ({})", category, name, instances.len(), expected_count));
+        }
+
+        for instance in instances {
+            if instance.object_type != *expected_object_type {
+                return Err(format!("the object type of one or more object instances in the {} {} ({}) doesn't match the expected type ({})", category, name, instance.object_type, expected_object_type))
+            }
+
+            ObjectInstance::validate(&instance)?;
+        }
+    }
+
+    Ok(())
 }
diff --git a/server/src/main.rs b/server/src/main.rs
index 79d64ee..58e4d92 100644
--- a/server/src/main.rs
+++ b/server/src/main.rs
@@ -1,48 +1,33 @@
+use std::collections::HashMap;
+
 use serde_json::json;
 use wgu::types::ObjectInstance;
-use wgu::modules::{ModuleItem, item_registry};
 
 fn main() -> Result<(), String> {
-    let modules = item_registry();
-
     // change these!
-    // for step 1
+    // 1 | creating a new object instance
     let object_type = "meta/number";
     let input = json!({
         "value": 1312
     });
 
-    // for step 2
-    let function = "local";
-    
-    // for step 3
-    let transform_source = "local.length";
-    let transform_destination = "meta/number:value";
-
-    // this creates a new object instance
     let some_object = ObjectInstance::from_object_type(object_type, input)?;
 
     println!("this is an object:");
     println!("{:#?}", some_object);
     println!("");
 
-    // this runs a function on it to calculate other properties
-    let some_object_with_data = match modules.get(format!("{}:func:{}", object_type, function).as_str()) {
-        Some(ModuleItem::Calculator(calc)) => calc(&some_object)?,
-        Some(_) => return Err(format!("if you're trying to run a ModuleItem::Function and not a ModuleItem::Calculator, you'll have to add the match arm for that")),
-        None => {
-            return Err(format!("the ModuleItem `{}:func:{}` doesn't exist. this is not necessarily bad in this example (if you changed `object_type`)", object_type, function));
-        }
-    };
+    // 2 | running a function on it
+    let function = "meta/number:func:local";
+    let mut function_input = HashMap::new();
+    function_input.insert(format!("main"), vec![some_object.clone()]);
 
-    println!("this is the same object with data:");
-    println!("{:#?}", some_object_with_data);
-    println!("");
+    println!("running function {}", function);
+    println!("input: {:#?}", function_input);
+    
+    let some_object_with_data = ObjectInstance::run_function(function, function_input, None)?;
 
-    let transformed = ObjectInstance::transform(&some_object_with_data, transform_source, transform_destination)?;
-
-    println!("this is what happens when we transform the {} property into a new {}:", transform_source, transform_destination);
-    println!("{:#?}", transformed);
+    println!("output: {:#?}", some_object_with_data);
 
     Ok(())
 }
diff --git a/server/src/modules.rs b/server/src/modules.rs
index feae52c..266aec6 100644
--- a/server/src/modules.rs
+++ b/server/src/modules.rs
@@ -3,14 +3,15 @@ use std::collections::HashMap;
 
 pub mod meta;
 
+pub type FunctionItem = HashMap<String, Vec<ObjectInstance>>;
+
 pub enum ModuleItem {
     Template(&'static str),
     Validator(fn(&ObjectInstance) -> Result<(), String>),
-    Calculator(fn(&ObjectInstance) -> Result<ObjectInstance, String>),
-    Function(fn(
-        inputs: HashMap<&str, &ObjectInstance>,
-        params: Option<HashMap<&str, &ObjectInstance>>
-    ) -> Result<HashMap<String, ObjectInstance>, String>)
+    Function((
+        &'static str, // template
+        fn(inputs: FunctionItem, params: Option<FunctionItem>) -> Result<FunctionItem, String>
+    ))
 }
 
 pub fn item_registry() -> HashMap<&'static str, ModuleItem> {
diff --git a/server/src/modules/meta.rs b/server/src/modules/meta.rs
index de0070d..6c90840 100644
--- a/server/src/modules/meta.rs
+++ b/server/src/modules/meta.rs
@@ -14,12 +14,12 @@ pub fn registry() -> HashMap<&'static str, ModuleItem> {
     // meta/text
     map.insert("meta/text", ModuleItem::Template(text::TEMPLATE));
     map.insert("meta/text:func:validator", ModuleItem::Validator(text::validate));
-    map.insert("meta/text:func:local", ModuleItem::Calculator(text::local));
+    map.insert("meta/text:func:local", ModuleItem::Function((text::TEMPLATE_LOCAL, text::local)));
     
     // meta/number
     map.insert("meta/number", ModuleItem::Template(number::TEMPLATE));
     map.insert("meta/number:func:validator", ModuleItem::Validator(number::validate));
-    map.insert("meta/number:func:local", ModuleItem::Calculator(number::local));
+    map.insert("meta/number:func:local", ModuleItem::Function((number::TEMPLATE_LOCAL, number::local)));
 
     // meta/bool
     map.insert("meta/bool", ModuleItem::Template(bool::TEMPLATE));
diff --git a/server/src/modules/meta/dummy.rs b/server/src/modules/meta/dummy.rs
index 31d0885..5a3f8a2 100644
--- a/server/src/modules/meta/dummy.rs
+++ b/server/src/modules/meta/dummy.rs
@@ -1,4 +1,5 @@
-pub const TEMPLATE: &str = r#"[input.value]
+pub const TEMPLATE: &str = r#"
+[input.value]
 transforms = ["meta/text:value"]
 subobjects = []
 conditions = []
diff --git a/server/src/modules/meta/number.rs b/server/src/modules/meta/number.rs
index f6330a2..93e5c1b 100644
--- a/server/src/modules/meta/number.rs
+++ b/server/src/modules/meta/number.rs
@@ -1,5 +1,7 @@
+use std::collections::HashMap;
 use serde_json::json;
-use crate::ObjectInstance;
+
+use crate::{modules::FunctionItem, types::ObjectInstance};
 
 pub const TEMPLATE: &str = r#"
 [input.value]
@@ -15,6 +17,18 @@ conditions = []
 duplicates = false
 "#;
 
+pub const TEMPLATE_LOCAL: &str = r#"
+[inputs.main]
+required = true
+object_type = "meta/number"
+count = 1
+
+[outputs.main]
+required = true
+object_type = "meta/number"
+count = 1
+"#;
+
 pub fn validate(obj: &ObjectInstance) -> Result<(), String> {
     let value = obj.input.get("value")
         .ok_or("input.value must exist")?;
@@ -25,18 +39,28 @@ pub fn validate(obj: &ObjectInstance) -> Result<(), String> {
     Ok(())
 }
 
-pub fn local(obj: &ObjectInstance) -> Result<ObjectInstance, String> {
-    let _value = obj.input.get("value")
-        .ok_or("input.value must exist")?;
+pub fn local(
+    inputs: FunctionItem,
+    _params: Option<FunctionItem>
+) 
+    -> Result<FunctionItem, String>
+{ 
+    let Some(main) = inputs.get("main")
+        else { unreachable!() };
 
-    let value = _value.as_number()
-        .ok_or("input.value must be a number")?;
+    let main_obj = &main[0];
 
-    let mut new = obj.clone();
-    new.local = json!({
+    let Some(value) = &main_obj.input.get("value")
+        else { unreachable!() };
+
+    let mut result_obj = ObjectInstance::from_object_type("meta/number", main_obj.input.clone())?;
+
+    result_obj.local = json!({
         "length": value.to_string().len()
     });
 
-    Ok(new)
-}
+    let mut result = HashMap::new();
+    result.insert(format!("main"), vec![result_obj]);
 
+    Ok(result)
+}
diff --git a/server/src/modules/meta/text.rs b/server/src/modules/meta/text.rs
index d3270fb..84c73b4 100644
--- a/server/src/modules/meta/text.rs
+++ b/server/src/modules/meta/text.rs
@@ -1,5 +1,7 @@
+use std::collections::HashMap;
 use serde_json::json;
-use crate::ObjectInstance;
+
+use crate::{modules::FunctionItem, types::ObjectInstance};
 
 pub const TEMPLATE: &str = r#"
 [input.value]
@@ -15,6 +17,19 @@ conditions = []
 duplicates = false
 "#;
 
+
+pub const TEMPLATE_LOCAL: &str = r#"
+[inputs.main]
+required = true
+object_type = "meta/text"
+count = 1
+
+[outputs.main]
+required = true
+object_type = "meta/text"
+count = 1
+"#;
+
 pub fn validate(obj: &ObjectInstance) -> Result<(), String> {
     let value = obj.input.get("value")
         .ok_or("input.value must exist")?;
@@ -25,17 +40,28 @@ pub fn validate(obj: &ObjectInstance) -> Result<(), String> {
     Ok(())
 }
 
-pub fn local(obj: &ObjectInstance) -> Result<ObjectInstance, String> {
-    let value = obj.input.get("value")
-        .ok_or("input.value must exist")?;
+pub fn local(
+    inputs: FunctionItem,
+    _params: Option<FunctionItem>
+)
+    -> Result<FunctionItem, String> 
+{
+    let Some(main) = inputs.get("main")
+        else { unreachable!() };
 
-    let value = value.as_str()
-        .ok_or("input.value must be a string")?;
+    let main_obj = &main[0];
 
-    let mut new = obj.clone();
-    new.local = json!({
-        "length": value.len()
+    let Some(value) = &main_obj.input.get("value")
+        else { unreachable!() };
+
+    let mut result_obj = ObjectInstance::from_object_type("meta/text", main_obj.input.clone())?;
+
+    result_obj.local = json!({
+        "length": value.to_string().len()
     });
 
-    Ok(new)
+    let mut result = HashMap::new();
+    result.insert(format!("main"), vec![result_obj]);
+
+    Ok(result)
 }
diff --git a/server/src/types.rs b/server/src/types.rs
index ef57cb9..89179ba 100644
--- a/server/src/types.rs
+++ b/server/src/types.rs
@@ -4,7 +4,7 @@ use std::collections::HashMap;
 
 #[derive(Serialize, Deserialize, Debug, Default, Clone)]
 pub struct ObjectInstance {
-    pub variant: u32,
+    pub variant: usize,
     pub plotted: bool,
     pub created: String,
     pub edited: String,
@@ -24,24 +24,39 @@ pub struct Log {
     level: String,
     variant: String,
     timestamp: String,
-    message: String,
+    message: String
 }
 
 #[derive(Deserialize, Debug, Default)]
 #[serde(default)]
 pub struct ObjectTemplate {
-    pub input: HashMap<String, TemplateProperty>,
-    pub local: HashMap<String, TemplateProperty>,
-    pub remote: HashMap<String, TemplateProperty>,
+    pub input: HashMap<String, ObjectTemplateProperty>,
+    pub local: HashMap<String, ObjectTemplateProperty>,
+    pub remote: HashMap<String, ObjectTemplateProperty>
 }
 
 // part of ObjectTemplate
 #[derive(Deserialize, Debug, Default)]
 #[serde(default)]
-pub struct TemplateProperty {
+pub struct ObjectTemplateProperty {
     pub transforms: Vec<String>,
     pub subobjects: Vec<String>,
     pub conditions: Vec<[String; 2]>,
     pub duplicates: bool
 }
 
+#[derive(Deserialize, Debug, Default)]
+#[serde(default)]
+pub struct FunctionTemplate {
+    pub inputs: HashMap<String, FunctionTemplateObject>,
+    pub params: HashMap<String, FunctionTemplateObject>,
+    pub outputs: HashMap<String, FunctionTemplateObject>
+}
+
+#[derive(Deserialize, Debug, Default)]
+#[serde(default)]
+pub struct FunctionTemplateObject {
+    pub required: bool,
+    pub object_type: String,
+    pub count: usize
+}