diff --git a/Cargo.lock b/Cargo.lock
index d1f009e..d23a6ec 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -140,6 +140,7 @@ dependencies = [
  "can-dbc",
  "clap",
  "daedalus",
+ "definition-rs",
  "futures-util",
  "num_enum",
  "phf",
@@ -161,6 +162,7 @@ dependencies = [
 name = "calypso-cangen"
 version = "0.1.0"
 dependencies = [
+ "definition-rs",
  "proc-macro2",
  "quote",
  "regex",
@@ -333,11 +335,22 @@ name = "daedalus"
 version = "0.1.0"
 dependencies = [
  "calypso-cangen",
+ "definition-rs",
  "proc-macro2",
  "quote",
  "serde_json",
 ]
 
+[[package]]
+name = "definition-rs"
+version = "0.1.0"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "schemars",
+ "serde",
+]
+
 [[package]]
 name = "digest"
 version = "0.10.7"
diff --git a/Cargo.toml b/Cargo.toml
index 1ea44e9..7196fab 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -24,6 +24,7 @@ serde = { version = "1.0.228", features = ["derive"] }
 serde_json = "1.0.150"
 regex = "1.12.3"
 schemars = "1.2.1"
+definition-rs = { path = "./Odyssey-Definitions/definition-rs"}
 
 [dependencies]
 rumqttc = "0.25.0"
@@ -49,6 +50,8 @@ num_enum = "0.7.5"
 [target.'cfg(target_os = "linux")'.dependencies]
 socketcan = { version = "3.6.1", features = ["tokio"] }
 
+definition-rs.workspace = true
+
 
 [build-dependencies]
 protobuf-codegen = "3.7.2"
diff --git a/Odyssey-Definitions b/Odyssey-Definitions
index b3a32f1..7972023 160000
--- a/Odyssey-Definitions
+++ b/Odyssey-Definitions
@@ -1 +1 @@
-Subproject commit b3a32f1621076a2169694d947f0668782f5d1301
+Subproject commit 7972023297513d015075a5f39ae148a9a06fb2c1
diff --git a/libs/calypso-cangen/Cargo.toml b/libs/calypso-cangen/Cargo.toml
index a674178..eb93376 100644
--- a/libs/calypso-cangen/Cargo.toml
+++ b/libs/calypso-cangen/Cargo.toml
@@ -12,3 +12,4 @@ serde_json = { workspace = true }
 thiserror = "2.0.18"
 schemars = { workspace = true }
 serde_path_to_error = "0.1.20"
+definition-rs.workspace = true
diff --git a/libs/calypso-cangen/src/can_gen_decode.rs b/libs/calypso-cangen/src/can_gen_decode.rs
index 4462034..dd246b8 100644
--- a/libs/calypso-cangen/src/can_gen_decode.rs
+++ b/libs/calypso-cangen/src/can_gen_decode.rs
@@ -1,4 +1,4 @@
-use crate::can_types::{CANMsg, CANPoint, NetField};
+use definition_rs::{CANMsg, CANPoint, NetField};
 use proc_macro2::Literal;
 use proc_macro2::TokenStream as ProcMacro2TokenStream;
 use quote::{format_ident, quote};
diff --git a/libs/calypso-cangen/src/can_gen_encode.rs b/libs/calypso-cangen/src/can_gen_encode.rs
index a324faa..5288a7c 100644
--- a/libs/calypso-cangen/src/can_gen_encode.rs
+++ b/libs/calypso-cangen/src/can_gen_encode.rs
@@ -1,4 +1,4 @@
-use crate::can_types::{CANMsg, CANPoint};
+use definition_rs::{CANMsg, CANPoint};
 use proc_macro2::Literal;
 use proc_macro2::TokenStream as ProcMacro2TokenStream;
 use quote::{format_ident, quote};
diff --git a/libs/calypso-cangen/src/can_gen_simulate.rs b/libs/calypso-cangen/src/can_gen_simulate.rs
index 904c857..e6741ad 100644
--- a/libs/calypso-cangen/src/can_gen_simulate.rs
+++ b/libs/calypso-cangen/src/can_gen_simulate.rs
@@ -1,4 +1,4 @@
-use crate::can_types::{CANMsg, CANPoint, NetField, Sim};
+use definition_rs::{CANMsg, CANPoint, NetField, Sim};
 use proc_macro2::TokenStream as ProcMacro2TokenStream;
 use quote::quote;
 use regex::Regex;
diff --git a/libs/calypso-cangen/src/can_types.rs b/libs/calypso-cangen/src/can_types.rs
deleted file mode 100644
index 25ab42a..0000000
--- a/libs/calypso-cangen/src/can_types.rs
+++ /dev/null
@@ -1,144 +0,0 @@
-use proc_macro2::TokenStream;
-use quote::quote;
-use schemars::JsonSchema;
-use serde::{Deserialize, Serialize};
-
-// Classes to represent levels of the CAN hierarchy
-// For more specific descriptions, refer to the README
-// in Embedded-Base/cangen
-
-// See https://nerdocs.atlassian.net/wiki/spaces/NER/pages/1162018881/Odyssey+Car+Configuration+Framework
-#[derive(Serialize, Deserialize, Clone)]
-#[serde(untagged, expecting = "CANMsg")]
-pub enum OdysseyMsg {
-    Can(CANMsg),
-    Meta(MetaMsg), // to be indexed, but not recieved - MUST GO LAST
-}
-
-#[derive(JsonSchema, Deserialize, Serialize, Debug, Clone)]
-#[serde(deny_unknown_fields)]
-pub struct MetaMsg {
-    pub desc: String,
-    pub fields: Vec<DumbNetField>,
-}
-
-/**
- *  Class representing a CAN message
- */
-#[derive(JsonSchema, Deserialize, Serialize, Clone, Debug)]
-#[serde(deny_unknown_fields)]
-pub struct CANMsg {
-    pub id: String,
-    pub desc: String,
-    pub points: Vec<CANPoint>,
-    pub fields: Vec<NetField>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub key: Option<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub is_ext: Option<bool>,
-    #[serde(default)]
-    pub bidir_mode: BidirMode,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub sim_freq: Option<f32>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub clients: Option<Vec<u16>>,
-}
-
-#[derive(JsonSchema, Debug, Deserialize, Serialize, PartialEq, Copy, Clone)]
-#[serde(rename_all(deserialize = "lowercase", serialize = "PascalCase"))]
-#[derive(Default)]
-pub enum BidirMode {
-    Oneshot,
-    #[default]
-    Broadcast,
-    Configuration,
-}
-
-impl quote::ToTokens for BidirMode {
-    fn to_tokens(&self, tokens: &mut TokenStream) {
-        let path: TokenStream = match self {
-            BidirMode::Broadcast => {
-                quote!(::calypso_cangen::can_types::BidirMode::Broadcast)
-            }
-            BidirMode::Oneshot => quote!(::calypso_cangen::can_types::BidirMode::Oneshot),
-            BidirMode::Configuration => {
-                panic!("Configuration sendable message is not available yet")
-            }
-        };
-        tokens.extend(path);
-    }
-}
-
-/**
- *  Class representing a `NetField` of a CAN message
- */
-#[derive(JsonSchema, Deserialize, Serialize, Clone, Debug)]
-#[serde(deny_unknown_fields)]
-pub struct NetField {
-    pub name: String,
-    pub unit: String,
-    pub doc: String,
-    pub desc: Option<String>,
-    pub values: Vec<usize>,
-}
-
-/**
- *  Class representing a `NetField` of a Meta message (there are no values)
- */
-#[derive(JsonSchema, Deserialize, Serialize, Clone, Debug)]
-#[serde(deny_unknown_fields)]
-pub struct DumbNetField {
-    pub name: String,
-    pub unit: String,
-    pub doc: String,
-    pub desc: Option<String>,
-}
-
-/**
- *  Class representing a CAN point of a `NetField`
- */
-#[derive(JsonSchema, Deserialize, Serialize, Clone, Debug)]
-#[serde(deny_unknown_fields)]
-pub struct CANPoint {
-    pub size: usize,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub name: Option<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub c_type: Option<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub parse: Option<bool>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub signed: Option<bool>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub endianness: Option<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub formatter: Option<Formatter>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub default: Option<f32>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub ieee754_f32: Option<bool>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub sim: Option<Sim>,
-}
-
-#[derive(JsonSchema, Deserialize, Serialize, Clone, Debug)]
-pub struct Formatter {
-    pub key: String,
-    pub arg: f32,
-}
-
-#[derive(JsonSchema, Deserialize, Serialize, Clone, Debug)]
-#[serde(untagged, deny_unknown_fields)]
-pub enum Sim {
-    SimRange {
-        min: f32,
-        max: f32,
-        inc_min: f32,
-        inc_max: f32,
-        #[serde(skip_serializing_if = "Option::is_none")]
-        round: Option<bool>,
-    },
-    SimDiscrete {
-        options: Vec<[f32; 2]>,
-    },
-}
diff --git a/libs/calypso-cangen/src/lib.rs b/libs/calypso-cangen/src/lib.rs
index 720e8c5..e3d89d6 100644
--- a/libs/calypso-cangen/src/lib.rs
+++ b/libs/calypso-cangen/src/lib.rs
@@ -1,7 +1,6 @@
 pub mod can_gen_decode;
 pub mod can_gen_encode;
 pub mod can_gen_simulate;
-pub mod can_types;
 pub mod validate;
 /**
  *  Path to CAN spec JSON files
diff --git a/libs/calypso-cangen/src/validate.rs b/libs/calypso-cangen/src/validate.rs
index c292b09..2fe60ce 100644
--- a/libs/calypso-cangen/src/validate.rs
+++ b/libs/calypso-cangen/src/validate.rs
@@ -1,5 +1,5 @@
 use crate::CANGEN_SPEC_PATH;
-use crate::can_types::{BidirMode, OdysseyMsg, Sim};
+use definition_rs::{BidirMode, OdysseyMsg, Sim};
 use regex::Regex;
 use std::collections::HashSet;
 use std::fs;
@@ -74,6 +74,11 @@ pub enum CANSpecError {
     #[error("Invalid topic name {0}")]
     InvalidTopicName(String),
 
+    #[error(
+        "Message {0} CAN ID {1} is too large.  Did you mean to use an extended ID (is_ext=true) ?"
+    )]
+    CanIdTooLarge(String, String),
+
     #[error(transparent)] // Pass-through for IO error
     IOError(#[from] std::io::Error),
 }
@@ -196,6 +201,15 @@ fn validate_msg(
                 ));
             }
 
+            let _id_int = u32::from_str_radix(_msg.id.clone().trim_start_matches("0x"), 16)
+                .unwrap_or_else(|_| panic!("Invalid CAN ID for message {}", _msg.desc));
+            if !_msg.is_ext.unwrap_or(false) && _id_int > 0x7FF {
+                _errors.push(CANSpecError::CanIdTooLarge(
+                    _msg.desc.clone(),
+                    _msg.id.clone(),
+                ));
+            }
+
             let mut _is_byte_aligned = true; // if the whole message has only byte aligned points
             let mut _contains_little_endians = false; // if the message contains any little endian points
 
diff --git a/libs/daedalus/Cargo.toml b/libs/daedalus/Cargo.toml
index 56096e7..ce27c41 100644
--- a/libs/daedalus/Cargo.toml
+++ b/libs/daedalus/Cargo.toml
@@ -11,3 +11,4 @@ calypso-cangen = { path = "../calypso-cangen" }
 proc-macro2.workspace = true
 quote.workspace = true
 serde_json.workspace = true
+definition-rs.workspace = true
diff --git a/libs/daedalus/src/lib.rs b/libs/daedalus/src/lib.rs
index f09f5f1..536451b 100644
--- a/libs/daedalus/src/lib.rs
+++ b/libs/daedalus/src/lib.rs
@@ -5,7 +5,7 @@ use calypso_cangen::CANGEN_SPEC_PATH;
 use calypso_cangen::can_gen_decode::gen_decoder_fn;
 use calypso_cangen::can_gen_encode::gen_encoder_fn;
 use calypso_cangen::can_gen_simulate::gen_simulate_canmsg;
-use calypso_cangen::can_types::{BidirMode, OdysseyMsg};
+use definition_rs::{BidirMode, OdysseyMsg};
 use proc_macro::TokenStream;
 use proc_macro2::TokenStream as ProcMacro2TokenStream;
 use quote::{format_ident, quote};
@@ -23,7 +23,7 @@ pub fn gen_decode_data(_item: TokenStream) -> TokenStream {
         use std::io::Cursor;
         use bitstream_io::{BigEndian, LittleEndian, BitReader, BitRead};
         use phf::phf_map;
-        use calypso_cangen::can_types::*;
+        use definition_rs::*;
         use crate::data::{DecodeData, FormatData};
     };
     let mut __decode_functions = quote! {};
@@ -137,7 +137,7 @@ pub fn gen_encode_data(_item: TokenStream) -> TokenStream {
     let __encode_prelude = quote! {
         use bitstream_io::{BigEndian, LittleEndian, BitWriter, BitWrite};
         use phf::phf_map;
-        use calypso_cangen::can_types::*;
+        use definition_rs::*;
         use crate::data::{EncodeData, FormatData};
     };
     let mut __encode_functions = quote! {};
diff --git a/src/bin/nerdbc.rs b/src/bin/nerdbc.rs
index 89d7875..0edc22d 100644
--- a/src/bin/nerdbc.rs
+++ b/src/bin/nerdbc.rs
@@ -1,7 +1,7 @@
 use std::{env, fs::File, io::Read};
 
-use calypso_cangen::can_types::{CANMsg, CANPoint, Formatter, NetField, Sim};
 use can_dbc::{ByteOrder, NumericValue};
+use definition_rs::{CANMsg, CANPoint, Formatter, NetField, Sim};
 
 /// decode a DBC file and paste (mostly) compliant JSON to stdout
 fn main() {
@@ -97,7 +97,7 @@ fn main() {
             is_ext: None,
             sim_freq: None,
             clients: None,
-            bidir_mode: calypso_cangen::can_types::BidirMode::Broadcast,
+            bidir_mode: definition_rs::BidirMode::Broadcast,
         });
     }
 
diff --git a/src/bin/to_json_schema.rs b/src/bin/to_json_schema.rs
index 1506689..922a61b 100644
--- a/src/bin/to_json_schema.rs
+++ b/src/bin/to_json_schema.rs
@@ -1,4 +1,4 @@
-use calypso_cangen::can_types::CANMsg;
+use definition_rs::CANMsg;
 use schemars::schema_for;
 
 fn main() {
diff --git a/src/main.rs b/src/main.rs
index 20eccf9..2fef319 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -13,8 +13,8 @@ use calypso::{
         serverdata::{self, ServerData},
     },
 };
-use calypso_cangen::can_types::BidirMode;
 use clap::Parser;
+use definition_rs::BidirMode;
 use protobuf::Message;
 use rumqttc::v5::{
     AsyncClient, Event, EventLoop, MqttOptions,