diff --git a/Cargo.lock b/Cargo.lock
index 92bfd2b..8fdbfac 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -950,6 +950,12 @@ version = "1.0.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "80af6f9131f277a45a3fba6ce8e2258037bb0477a67e610d3c1fe046ab31de47"
 
+[[package]]
+name = "ryu"
+version = "1.0.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e86697c916019a8588c99b5fac3cead74ec0b4b819707a682fd4d23fa0ce1ba1"
+
 [[package]]
 name = "scopeguard"
 version = "1.2.0"
@@ -976,6 +982,17 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "serde_json"
+version = "1.0.115"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "12dc5c46daa8e9fdf4f5e71b6cf9a53f2487da0e86e55808e2d35539666497dd"
+dependencies = [
+ "itoa",
+ "ryu",
+ "serde",
+]
+
 [[package]]
 name = "sharded-slab"
 version = "0.1.7"
@@ -1070,6 +1087,8 @@ dependencies = [
  "rcgen",
  "rmp",
  "rustls 0.23.4",
+ "serde",
+ "serde_json",
  "tempfile",
  "time",
  "tokio",
diff --git a/Cargo.toml b/Cargo.toml
index 3c736ef..872c15f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -16,6 +16,8 @@ prost = "0.12.4"
 rcgen = "0.13.1"
 rmp = "0.8.12"
 rustls = { version = "0.23.4", default-features = false, features = ["ring", "logging", "std", "tls12"] }
+serde = "1.0.197"
+serde_json = "1.0.115"
 tempfile = "3.10.1"
 time = "0.3.35"
 tokio = { version = "1.37.0", features = ["full"] }
diff --git a/src/example.rs b/src/example.rs
index a44922b..6a2b36a 100644
--- a/src/example.rs
+++ b/src/example.rs
@@ -6,7 +6,7 @@ use crate::{
         provider::Provider,
         DResult,
     },
-    values::Value,
+    values::{Value, ValueKind},
 };
 
 pub struct ExampleProvider {}
@@ -61,16 +61,22 @@ impl DataSource for ExampleDataSource {
     }
 
     fn read(&self, config: Value) -> DResult<Value> {
-        Ok(Value::Object(BTreeMap::from([
+        Ok(Value::Known(ValueKind::Object(BTreeMap::from([
             (
                 "name".to_owned(),
                 match config {
-                    Value::Object(mut obj) => obj.remove("name").unwrap(),
+                    Value::Known(ValueKind::Object(mut obj)) => obj.remove("name").unwrap(),
                     _ => unreachable!(),
                 },
             ),
-            ("meow".to_owned(), Value::String("mrrrrr".to_owned())),
-            ("id".to_owned(), Value::String("0".to_owned())),
-        ])))
+            (
+                "meow".to_owned(),
+                Value::Known(ValueKind::String("mrrrrr".to_owned())),
+            ),
+            (
+                "id".to_owned(),
+                Value::Known(ValueKind::String("0".to_owned())),
+            ),
+        ]))))
     }
 }
diff --git a/src/framework/datasource.rs b/src/framework/datasource.rs
index 798497a..6261339 100644
--- a/src/framework/datasource.rs
+++ b/src/framework/datasource.rs
@@ -1,6 +1,6 @@
 use std::collections::HashMap;
 
-use crate::values::Value;
+use crate::values::{Type, Value};
 
 use super::DResult;
 
@@ -56,4 +56,26 @@ impl Mode {
     pub fn computed(&self) -> bool {
         matches!(self, Self::OptionalComputed | Self::Computed)
     }
-}
\ No newline at end of file
+}
+
+impl Schema {
+    pub fn typ(&self) -> Type {
+        let attrs = self
+            .attributes
+            .iter()
+            .map(|(name, attr)| {
+                let attr_type = match attr {
+                    Attribute::Int64 { .. } => Type::Number,
+                    Attribute::String { .. } => Type::String,
+                };
+
+                (name.clone(), attr_type)
+            })
+            .collect();
+
+        Type::Object {
+            attrs,
+            optionals: vec![],
+        }
+    }
+}
diff --git a/src/framework/mod.rs b/src/framework/mod.rs
index 425f5e9..2c7c9d7 100644
--- a/src/framework/mod.rs
+++ b/src/framework/mod.rs
@@ -10,3 +10,17 @@ pub struct Diagnostics {
 }
 
 pub type DResult<T> = Result<T, Diagnostics>;
+
+impl Diagnostics {
+    pub fn error_string(msg: String) -> Self {
+        Self {
+            errors: vec![msg],
+        }
+    }
+}
+
+impl<E: std::error::Error + std::fmt::Debug> From<E> for Diagnostics {
+    fn from(value: E) -> Self {
+        Self::error_string(format!("{:?}", value))
+    }
+}
diff --git a/src/server/grpc.rs b/src/server/grpc.rs
index 1fdec24..5564936 100644
--- a/src/server/grpc.rs
+++ b/src/server/grpc.rs
@@ -237,10 +237,32 @@ impl Provider for super::ProviderHandler {
             .get(&request.get_ref().type_name)
             .unwrap();
 
-        let state = ds.read(crate::values::Value::Object(BTreeMap::from([(
-            "name".to_owned(),
-            crate::values::Value::String("mykitten".to_owned()),
-        )])));
+        let typ = ds.schema().typ();
+        let config = match &request.get_ref().config {
+            None => crate::values::Value::Null,
+            Some(v) => {
+                let value = crate::values::Value::msg_unpack(&v.msgpack, &typ);
+                match value {
+                    Ok(value) => value,
+                    Err(errs) => {
+                        return Ok(Response::new(tfplugin6::read_data_source::Response {
+                            deferred: None,
+                            state: None,
+                            diagnostics: errs.to_tfplugin_diags(),
+                        }));
+                    }
+                }
+            }
+        };
+
+        let state = ds.read(crate::values::Value::Known(
+            crate::values::ValueKind::Object(BTreeMap::from([(
+                "name".to_owned(),
+                crate::values::Value::Known(crate::values::ValueKind::String(
+                    "mykitten".to_owned(),
+                )),
+            )])),
+        ));
         let (state, diagnostics) = match state {
             Ok(s) => (
                 Some(tfplugin6::DynamicValue {
diff --git a/src/server/mod.rs b/src/server/mod.rs
index 6112221..a0cb313 100644
--- a/src/server/mod.rs
+++ b/src/server/mod.rs
@@ -5,9 +5,8 @@ use std::collections::HashMap;
 
 use tokio_util::sync::CancellationToken;
 
-use crate::framework::datasource::{self, DataSource};
+use crate::framework::datasource::DataSource;
 use crate::framework::provider::Provider;
-use crate::framework::DResult;
 
 pub use grpc::plugin::grpc_controller_server::GrpcControllerServer;
 pub use grpc::tfplugin6::provider_server::ProviderServer;
diff --git a/src/values.rs b/src/values.rs
index 2e3f11f..474287f 100644
--- a/src/values.rs
+++ b/src/values.rs
@@ -1,32 +1,102 @@
 // check terraform-plugin-go tfprotov6/internal/toproto for convesions
 //                           tftypes                    for types and values
 
-use std::collections::{BTreeMap, HashMap};
+use std::{
+    collections::{BTreeMap, HashMap, HashSet},
+    io::{self, Read},
+};
+
+use rmp::encode::write_bool;
+
+use crate::framework::{DResult, Diagnostics};
 
 pub enum Type {
+    Bool,
     Number,
     String,
+    Dynamic,
+    /// A list of elements of the same type.
+    List {
+        elem: Box<Type>,
+    },
+    /// A bunch of unordered string-value pair of the same type.
+    Map {
+        elem: Box<Type>,
+    },
+    /// A set of unique values of the same type.
+    Set {
+        elem: Box<Type>,
+    },
+    /// A bunch of unordered string-value pairs of different types.
+    /// The attributes are statically known.
+    Object {
+        attrs: HashMap<String, Type>,
+        /// The attributes in `attrs` that are optional.
+        /// Always empty for now because of JSON reasons.
+        optionals: Vec<String>,
+    },
+    /// An ordered list of values of different types.
+    Tuple {
+        elems: Vec<Type>,
+    },
 }
 
 impl Type {
     pub fn to_json(&self) -> String {
-        match *self {
-            Self::String => "\"string\"".to_owned(),
-            Self::Number => "\"number\"".to_owned(),
+        let value = self.to_json_inner();
+        serde_json::to_string(&value).unwrap()
+    }
+    pub fn to_json_inner(&self) -> serde_json::Value {
+        use serde_json::Value;
+
+        let compound =
+            |tag: &str, inner: Value| Value::Array(vec![Value::String(tag.to_owned()), inner]);
+
+        match self {
+            Self::Bool => Value::String("bool".to_owned()),
+            Self::String => Value::String("string".to_owned()),
+            Self::Number => Value::String("number".to_owned()),
+            Self::Dynamic => Value::String("dynamic".to_owned()),
+            Self::List { elem } => compound("list", elem.to_json_inner()),
+            Self::Map { elem } => compound("map", elem.to_json_inner()),
+            Self::Set { elem } => compound("set", elem.to_json_inner()),
+            Self::Object {
+                attrs,
+                optionals: _,
+            } => compound(
+                "object",
+                Value::Object(
+                    attrs
+                        .iter()
+                        .map(|(k, v)| (k.clone(), v.to_json_inner()))
+                        .collect(),
+                ),
+            ),
+            Self::Tuple { elems } => compound(
+                "tuple",
+                elems.iter().map(|elem| elem.to_json_inner()).collect(),
+            ),
         }
     }
 }
 
-// this is very dumb and wrong
+#[derive(Debug)]
 pub enum Value {
-    String(String),
-    Object(BTreeMap<String, Value>),
+    Known(ValueKind),
+    Unknown,
+    Null,
 }
 
-impl Value {
-    pub fn ty(&self) -> Type {
-        todo!()
-    } 
+#[derive(Debug)]
+pub enum ValueKind {
+    String(String),
+    Number(f64),
+    Bool(bool),
+    List(Vec<Value>),
+    Set(Vec<Value>),
+    Map(BTreeMap<String, Value>),
+    Tuple(Vec<Value>),
+    Object(BTreeMap<String, Value>),
 }
 
 // marshal msg pack
@@ -35,22 +105,170 @@ impl Value {
 impl Value {
     pub fn msg_pack(&self) -> Vec<u8> {
         let mut buf = Vec::new();
-        self.msg_pack_inner(&mut buf);
+        self.msg_pack_inner(&mut buf)
+            .expect("writing to Vec<u8> cannot fail");
         buf
     }
 
-    pub fn msg_pack_inner(&self, v: &mut Vec<u8>) {
-        match self {
-            Value::String(s) => {
-                rmp::encode::write_str(v, s).unwrap();
+    pub fn msg_pack_inner(&self, wr: &mut Vec<u8>) -> std::io::Result<()> {
+        use rmp::encode as mp;
+
+        let known = match self {
+            Value::Unknown => {
+                wr.extend_from_slice(&[0xd4, 0, 0]);
+                return Ok(());
             }
-            Value::Object(o) => {
-                rmp::encode::write_map_len(v, o.len().try_into().unwrap()).unwrap();
+            Value::Null => {
+                mp::write_nil(wr)?;
+                return Ok(());
+            }
+            Value::Known(known) => known,
+        };
+
+        match known {
+            ValueKind::String(s) => {
+                mp::write_str(wr, s)?;
+            }
+            &ValueKind::Number(n) => {
+                if n.is_infinite() {
+                    if n.signum() == -1.0 {
+                        mp::write_f64(wr, f64::NEG_INFINITY)?;
+                    } else {
+                        mp::write_f64(wr, f64::INFINITY)?;
+                    }
+                } else if (n as i64 as f64) == n {
+                    // is int
+                    mp::write_i64(wr, n as i64)?;
+                } else {
+                    mp::write_f64(wr, n)?;
+                }
+                // Terraform handles bigfloats but we do emphatically not care
+            }
+            ValueKind::Bool(b) => {
+                mp::write_bool(wr, *b)?;
+            }
+            ValueKind::List(elems) | ValueKind::Set(elems) | ValueKind::Tuple(elems) => {
+                mp::write_array_len(wr, elems.len().try_into().unwrap())?;
+                for elem in elems {
+                    elem.msg_pack_inner(wr)?;
+                }
+            }
+            ValueKind::Map(o) | ValueKind::Object(o) => {
+                mp::write_map_len(wr, o.len().try_into().unwrap())?;
                 for (key, val) in o {
-                    rmp::encode::write_str(v, key).unwrap();
-                    val.msg_pack_inner(v);
+                    mp::write_str(wr, key)?;
+                    val.msg_pack_inner(wr)?;
                 }
             }
         }
+
+        Ok(())
     }
-}
\ No newline at end of file
+
+    pub fn msg_unpack(data: &[u8], typ: &Type) -> DResult<Self> {
+        let mut read = io::Cursor::new(data);
+        Self::msg_unpack_inner(&mut read, typ)
+    }
+
+    fn msg_unpack_inner(rd: &mut io::Cursor<&[u8]>, typ: &Type) -> DResult<Self> {
+        use rmp::decode as mp;
+
+        if let Ok(()) = mp::read_nil(rd) {
+            return Ok(Value::Null);
+        }
+        rd.set_position(rd.position() - 1); // revert past the nil
+
+        let read_string = |rd: &mut io::Cursor<&[u8]>| -> DResult<String> {
+            let len = std::cmp::min(mp::read_str_len(rd)?, 1024 * 1024); // you're not gonna get more than a 1MB string...
+            let mut buf = Vec::with_capacity(len as usize);
+            rd.read_exact(&mut buf)?;
+            Ok(String::from_utf8(buf)?)
+        };
+
+        let value = match typ {
+            Type::Bool => {
+                let b = mp::read_bool(rd)?;
+                ValueKind::Bool(b)
+            }
+            Type::Number => {
+                let prev = rd.position();
+                if let Ok(int) = mp::read_int::<i64, _>(rd) {
+                    ValueKind::Number(int as f64)
+                } else {
+                    rd.set_position(prev);
+                    if let Ok(f32) = mp::read_f32(rd) {
+                        ValueKind::Number(f32 as f64)
+                    } else {
+                        rd.set_position(prev);
+                        let f64 = mp::read_f64(rd)?;
+                        ValueKind::Number(f64)
+                    }
+                }
+            }
+            Type::String => ValueKind::String(read_string(rd)?),
+            Type::Dynamic => todo!("dynamic"),
+            Type::List { elem } => {
+                let len = mp::read_array_len(rd)?;
+                let elems = (0..len)
+                    .map(|_| Value::msg_unpack_inner(rd, &elem))
+                    .collect::<Result<Vec<_>, _>>()?;
+                ValueKind::List(elems)
+            }
+            Type::Map { elem } => {
+                let len = mp::read_array_len(rd)?;
+                let elems = (0..len)
+                    .map(|_| -> DResult<_> {
+                        let key = read_string(rd)?;
+                        let value = Value::msg_unpack_inner(rd, &elem)?;
+                        Ok((key, value))
+                    })
+                    .collect::<DResult<BTreeMap<_, _>>>()?;
+                ValueKind::Map(elems)
+            }
+            Type::Set { elem } => {
+                let len = mp::read_array_len(rd)?;
+                let elems = (0..len)
+                    .map(|_| Value::msg_unpack_inner(rd, &elem))
+                    .collect::<Result<Vec<_>, _>>()?;
+                ValueKind::Set(elems)
+            }
+            Type::Object { attrs, optionals } => {
+                assert!(optionals.is_empty());
+                let len = mp::read_array_len(rd)?;
+                if attrs.len() != (len as usize) {
+                    return Err(Diagnostics::error_string(format!(
+                        "expected {} attrs, found {len} attrs in object",
+                        attrs.len()
+                    )));
+                }
+                let elems = (0..len)
+                    .map(|_| -> DResult<_> {
+                        let key = read_string(rd)?;
+                        let typ = attrs.get(&key).ok_or_else(|| {
+                            Diagnostics::error_string(format!("unexpected attribute: {key}"))
+                        })?;
+                        let value = Value::msg_unpack_inner(rd, &typ)?;
+                        Ok((key, value))
+                    })
+                    .collect::<DResult<BTreeMap<_, _>>>()?;
+                ValueKind::Object(elems)
+            }
+            Type::Tuple { elems } => {
+                let len = mp::read_array_len(rd)?;
+                if elems.len() != (len as usize) {
+                    return Err(Diagnostics::error_string(format!(
+                        "expected {} elems, found {len} elems in tuple",
+                        elems.len()
+                    )));
+                }
+                let elems = elems
+                    .iter()
+                    .map(|typ| Value::msg_unpack_inner(rd, &typ))
+                    .collect::<Result<Vec<_>, _>>()?;
+                ValueKind::List(elems)
+            }
+        };
+
+        Ok(Value::Known(value))
+    }
+}