diff --git a/crates/console/prometeu-bytecode/src/lib.rs b/crates/console/prometeu-bytecode/src/lib.rs
index 1e815bd5..3a936e7a 100644
--- a/crates/console/prometeu-bytecode/src/lib.rs
+++ b/crates/console/prometeu-bytecode/src/lib.rs
@@ -18,6 +18,6 @@ pub use assembler::{assemble, AsmError};
 pub use decoder::{decode_next, DecodeError};
 pub use disassembler::disassemble;
 pub use layout::{compute_function_layouts, FunctionLayout};
-pub use model::{BytecodeLoader, FunctionMeta, LoadError};
+pub use model::{BytecodeLoader, FunctionMeta, LoadError, SyscallDecl};
 pub use program_image::ProgramImage;
 pub use value::{HeapRef, Value};
diff --git a/crates/console/prometeu-bytecode/src/model.rs b/crates/console/prometeu-bytecode/src/model.rs
index 2c162116..aabffc01 100644
--- a/crates/console/prometeu-bytecode/src/model.rs
+++ b/crates/console/prometeu-bytecode/src/model.rs
@@ -1,6 +1,7 @@
 use crate::abi::SourceSpan;
 use crate::opcode::OpCode;
 use serde::{Deserialize, Serialize};
+use std::collections::HashSet;
 
 /// An entry in the Constant Pool.
 ///
@@ -35,6 +36,9 @@ pub enum LoadError {
     InvalidFunctionIndex,
     MalformedHeader,
     MalformedSection,
+    MissingSyscallSection,
+    DuplicateSyscallIdentity,
+    InvalidUtf8,
     UnexpectedEof,
 }
 
@@ -60,6 +64,22 @@ pub struct Export {
     pub func_idx: u32,
 }
 
+#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub struct SyscallDecl {
+    pub module: String,
+    pub name: String,
+    pub version: u16,
+    pub arg_slots: u16,
+    pub ret_slots: u16,
+}
+
+const SECTION_KIND_CONST_POOL: u32 = 0;
+const SECTION_KIND_FUNCTIONS: u32 = 1;
+const SECTION_KIND_CODE: u32 = 2;
+const SECTION_KIND_DEBUG: u32 = 3;
+const SECTION_KIND_EXPORTS: u32 = 4;
+const SECTION_KIND_SYSCALLS: u32 = 5;
+
 /// Represents the final serialized format of a PBS v0 module.
 ///
 /// This structure is a pure data container for the PBS format. It does NOT
@@ -74,6 +94,7 @@ pub struct BytecodeModule {
     pub code: Vec<u8>,
     pub debug_info: Option<DebugInfo>,
     pub exports: Vec<Export>,
+    pub syscalls: Vec<SyscallDecl>,
 }
 
 impl BytecodeModule {
@@ -84,23 +105,25 @@ impl BytecodeModule {
         let debug_data =
             self.debug_info.as_ref().map(|di| self.serialize_debug(di)).unwrap_or_default();
         let export_data = self.serialize_exports();
+        let syscall_data = self.serialize_syscalls();
 
         let mut final_sections = Vec::new();
         if !cp_data.is_empty() {
-            final_sections.push((0, cp_data));
+            final_sections.push((SECTION_KIND_CONST_POOL, cp_data));
         }
         if !func_data.is_empty() {
-            final_sections.push((1, func_data));
+            final_sections.push((SECTION_KIND_FUNCTIONS, func_data));
         }
         if !code_data.is_empty() {
-            final_sections.push((2, code_data));
+            final_sections.push((SECTION_KIND_CODE, code_data));
         }
         if !debug_data.is_empty() {
-            final_sections.push((3, debug_data));
+            final_sections.push((SECTION_KIND_DEBUG, debug_data));
         }
         if !export_data.is_empty() {
-            final_sections.push((4, export_data));
+            final_sections.push((SECTION_KIND_EXPORTS, export_data));
         }
+        final_sections.push((SECTION_KIND_SYSCALLS, syscall_data));
 
         let mut out = Vec::new();
         // Magic "PBS\0"
@@ -219,6 +242,26 @@ impl BytecodeModule {
         }
         data
     }
+
+    fn serialize_syscalls(&self) -> Vec<u8> {
+        let mut data = Vec::new();
+        data.extend_from_slice(&(self.syscalls.len() as u32).to_le_bytes());
+        for syscall in &self.syscalls {
+            let module = syscall.module.as_bytes();
+            let name = syscall.name.as_bytes();
+            assert!(u16::try_from(module.len()).is_ok(), "SYSC module name exceeds u16 length");
+            assert!(u16::try_from(name.len()).is_ok(), "SYSC syscall name exceeds u16 length");
+
+            data.extend_from_slice(&(module.len() as u16).to_le_bytes());
+            data.extend_from_slice(module);
+            data.extend_from_slice(&(name.len() as u16).to_le_bytes());
+            data.extend_from_slice(name);
+            data.extend_from_slice(&syscall.version.to_le_bytes());
+            data.extend_from_slice(&syscall.arg_slots.to_le_bytes());
+            data.extend_from_slice(&syscall.ret_slots.to_le_bytes());
+        }
+        data
+    }
 }
 
 pub struct BytecodeLoader;
@@ -296,35 +339,45 @@ impl BytecodeLoader {
             code: Vec::new(),
             debug_info: None,
             exports: Vec::new(),
+            syscalls: Vec::new(),
         };
+        let mut has_syscalls = false;
 
         for (kind, offset, length) in sections {
             let section_data = &bytes[offset as usize..(offset + length) as usize];
             match kind {
-                0 => {
+                SECTION_KIND_CONST_POOL => {
                     // Const Pool
                     module.const_pool = parse_const_pool(section_data)?;
                 }
-                1 => {
+                SECTION_KIND_FUNCTIONS => {
                     // Functions
                     module.functions = parse_functions(section_data)?;
                 }
-                2 => {
+                SECTION_KIND_CODE => {
                     // Code
                     module.code = section_data.to_vec();
                 }
-                3 => {
+                SECTION_KIND_DEBUG => {
                     // Debug Info
                     module.debug_info = Some(parse_debug_section(section_data)?);
                 }
-                4 => {
+                SECTION_KIND_EXPORTS => {
                     // Exports
                     module.exports = parse_exports(section_data)?;
                 }
+                SECTION_KIND_SYSCALLS => {
+                    module.syscalls = parse_syscalls(section_data)?;
+                    has_syscalls = true;
+                }
                 _ => {} // Skip unknown or optional sections
             }
         }
 
+        if !has_syscalls {
+            return Err(LoadError::MissingSyscallSection);
+        }
+
         // Additional validations
         validate_module(&module)?;
 
@@ -520,7 +573,74 @@ fn parse_exports(data: &[u8]) -> Result<Vec<Export>, LoadError> {
     Ok(exports)
 }
 
+fn parse_syscalls(data: &[u8]) -> Result<Vec<SyscallDecl>, LoadError> {
+    if data.len() < 4 {
+        return Err(LoadError::MalformedSection);
+    }
+
+    let count = u32::from_le_bytes([data[0], data[1], data[2], data[3]]) as usize;
+    let mut syscalls = Vec::with_capacity(count);
+    let mut pos = 4;
+
+    for _ in 0..count {
+        if pos + 2 > data.len() {
+            return Err(LoadError::UnexpectedEof);
+        }
+        let module_len = u16::from_le_bytes(data[pos..pos + 2].try_into().unwrap()) as usize;
+        pos += 2;
+        if pos + module_len > data.len() {
+            return Err(LoadError::UnexpectedEof);
+        }
+        let module =
+            std::str::from_utf8(&data[pos..pos + module_len]).map_err(|_| LoadError::InvalidUtf8)?;
+        pos += module_len;
+
+        if pos + 2 > data.len() {
+            return Err(LoadError::UnexpectedEof);
+        }
+        let name_len = u16::from_le_bytes(data[pos..pos + 2].try_into().unwrap()) as usize;
+        pos += 2;
+        if pos + name_len > data.len() {
+            return Err(LoadError::UnexpectedEof);
+        }
+        let name =
+            std::str::from_utf8(&data[pos..pos + name_len]).map_err(|_| LoadError::InvalidUtf8)?;
+        pos += name_len;
+
+        if pos + 6 > data.len() {
+            return Err(LoadError::UnexpectedEof);
+        }
+        let version = u16::from_le_bytes(data[pos..pos + 2].try_into().unwrap());
+        let arg_slots = u16::from_le_bytes(data[pos + 2..pos + 4].try_into().unwrap());
+        let ret_slots = u16::from_le_bytes(data[pos + 4..pos + 6].try_into().unwrap());
+        pos += 6;
+
+        syscalls.push(SyscallDecl {
+            module: module.to_owned(),
+            name: name.to_owned(),
+            version,
+            arg_slots,
+            ret_slots,
+        });
+    }
+
+    if pos != data.len() {
+        return Err(LoadError::MalformedSection);
+    }
+
+    Ok(syscalls)
+}
+
 fn validate_module(module: &BytecodeModule) -> Result<(), LoadError> {
+    let mut syscall_identities = HashSet::with_capacity(module.syscalls.len());
+    for syscall in &module.syscalls {
+        if !syscall_identities
+            .insert((syscall.module.clone(), syscall.name.clone(), syscall.version))
+        {
+            return Err(LoadError::DuplicateSyscallIdentity);
+        }
+    }
+
     for func in &module.functions {
         // Opcode stream bounds
         if (func.code_offset as usize) + (func.code_len as usize) > module.code.len() {
@@ -591,6 +711,36 @@ mod tests {
         h
     }
 
+    fn minimal_module() -> BytecodeModule {
+        BytecodeModule {
+            version: 0,
+            const_pool: vec![],
+            functions: vec![],
+            code: vec![],
+            debug_info: None,
+            exports: vec![],
+            syscalls: vec![],
+        }
+    }
+
+    fn build_pbs_with_sections(sections: Vec<(u32, Vec<u8>)>) -> Vec<u8> {
+        let mut data = create_header(sections.len() as u32);
+        let mut offset = 32 + (sections.len() as u32 * 12);
+
+        for (kind, section_data) in &sections {
+            data.extend_from_slice(&kind.to_le_bytes());
+            data.extend_from_slice(&offset.to_le_bytes());
+            data.extend_from_slice(&(section_data.len() as u32).to_le_bytes());
+            offset += section_data.len() as u32;
+        }
+
+        for (_, section_data) in sections {
+            data.extend_from_slice(&section_data);
+        }
+
+        data
+    }
+
     #[test]
     fn test_invalid_magic() {
         let mut data = create_header(0);
@@ -645,10 +795,10 @@ mod tests {
 
     #[test]
     fn test_invalid_function_code_offset() {
-        let mut data = create_header(2);
-        // Section 1: Functions, Kind 1, Offset 64, Length 20 (Header 4 + 1 entry 16)
+        let mut data = create_header(3);
+        // Section 1: Functions, Kind 1, Offset 80, Length 20 (Header 4 + 1 entry 16)
         data.extend_from_slice(&1u32.to_le_bytes());
-        data.extend_from_slice(&64u32.to_le_bytes());
+        data.extend_from_slice(&80u32.to_le_bytes());
         data.extend_from_slice(&20u32.to_le_bytes());
 
         // Section 2: Code, Kind 2, Offset 128, Length 10
@@ -656,25 +806,31 @@ mod tests {
         data.extend_from_slice(&128u32.to_le_bytes());
         data.extend_from_slice(&10u32.to_le_bytes());
 
+        // Section 3: SYSC, Kind 5, Offset 160, Length 4 (empty)
+        data.extend_from_slice(&5u32.to_le_bytes());
+        data.extend_from_slice(&160u32.to_le_bytes());
+        data.extend_from_slice(&4u32.to_le_bytes());
+
         data.resize(256, 0);
 
         // Setup functions section
-        let func_data_start = 64;
+        let func_data_start = 80;
         data[func_data_start..func_data_start + 4].copy_from_slice(&1u32.to_le_bytes()); // 1 function
         let entry_start = func_data_start + 4;
         data[entry_start..entry_start + 4].copy_from_slice(&5u32.to_le_bytes()); // code_offset = 5
         data[entry_start + 4..entry_start + 8].copy_from_slice(&10u32.to_le_bytes()); // code_len = 10
                                                                                       // 5 + 10 = 15 > 10 (code section length)
+        data[160..164].copy_from_slice(&0u32.to_le_bytes());
 
         assert_eq!(BytecodeLoader::load(&data), Err(LoadError::InvalidFunctionIndex));
     }
 
     #[test]
     fn test_invalid_const_index() {
-        let mut data = create_header(2);
-        // Section 1: Const Pool, Kind 0, Offset 64, Length 4 (Empty CP)
+        let mut data = create_header(3);
+        // Section 1: Const Pool, Kind 0, Offset 80, Length 4 (Empty CP)
         data.extend_from_slice(&0u32.to_le_bytes());
-        data.extend_from_slice(&64u32.to_le_bytes());
+        data.extend_from_slice(&80u32.to_le_bytes());
         data.extend_from_slice(&4u32.to_le_bytes());
 
         // Section 2: Code, Kind 2, Offset 128, Length 6 (PushConst 0)
@@ -682,25 +838,105 @@ mod tests {
         data.extend_from_slice(&128u32.to_le_bytes());
         data.extend_from_slice(&6u32.to_le_bytes());
 
+        // Section 3: SYSC, Kind 5, Offset 160, Length 4 (empty)
+        data.extend_from_slice(&5u32.to_le_bytes());
+        data.extend_from_slice(&160u32.to_le_bytes());
+        data.extend_from_slice(&4u32.to_le_bytes());
+
         data.resize(256, 0);
 
         // Setup empty CP
-        data[64..68].copy_from_slice(&0u32.to_le_bytes());
+        data[80..84].copy_from_slice(&0u32.to_le_bytes());
 
         // Setup code with PushConst 0
         data[128..130].copy_from_slice(&(OpCode::PushConst as u16).to_le_bytes());
         data[130..134].copy_from_slice(&0u32.to_le_bytes());
+        data[160..164].copy_from_slice(&0u32.to_le_bytes());
 
         assert_eq!(BytecodeLoader::load(&data), Err(LoadError::InvalidConstIndex));
     }
 
     #[test]
-    fn test_valid_minimal_load() {
+    fn test_missing_sysc_section_is_rejected() {
         let data = create_header(0);
+
+        assert_eq!(BytecodeLoader::load(&data), Err(LoadError::MissingSyscallSection));
+    }
+
+    #[test]
+    fn test_valid_minimal_load_with_empty_sysc() {
+        let data = minimal_module().serialize();
         let module = BytecodeLoader::load(&data).unwrap();
         assert_eq!(module.version, 0);
         assert!(module.const_pool.is_empty());
         assert!(module.functions.is_empty());
         assert!(module.code.is_empty());
+        assert!(module.syscalls.is_empty());
+    }
+
+    #[test]
+    fn test_valid_sysc_roundtrip() {
+        let mut module = minimal_module();
+        module.syscalls = vec![SyscallDecl {
+            module: "gfx".into(),
+            name: "draw_line".into(),
+            version: 1,
+            arg_slots: 4,
+            ret_slots: 0,
+        }];
+
+        let data = module.serialize();
+        let loaded = BytecodeLoader::load(&data).unwrap();
+
+        assert_eq!(loaded.syscalls, module.syscalls);
+    }
+
+    #[test]
+    fn test_malformed_sysc_section_is_rejected() {
+        let data = build_pbs_with_sections(vec![(SECTION_KIND_SYSCALLS, vec![1, 0, 0])]);
+
+        assert_eq!(BytecodeLoader::load(&data), Err(LoadError::MalformedSection));
+    }
+
+    #[test]
+    fn test_invalid_utf8_in_sysc_section_is_rejected() {
+        let mut sysc = Vec::new();
+        sysc.extend_from_slice(&1u32.to_le_bytes());
+        sysc.extend_from_slice(&1u16.to_le_bytes());
+        sysc.push(0xFF);
+        sysc.extend_from_slice(&1u16.to_le_bytes());
+        sysc.push(b'x');
+        sysc.extend_from_slice(&1u16.to_le_bytes());
+        sysc.extend_from_slice(&0u16.to_le_bytes());
+        sysc.extend_from_slice(&0u16.to_le_bytes());
+
+        let data = build_pbs_with_sections(vec![(SECTION_KIND_SYSCALLS, sysc)]);
+
+        assert_eq!(BytecodeLoader::load(&data), Err(LoadError::InvalidUtf8));
+    }
+
+    #[test]
+    fn test_duplicate_sysc_identity_is_rejected() {
+        let mut module = minimal_module();
+        module.syscalls = vec![
+            SyscallDecl {
+                module: "system".into(),
+                name: "has_cart".into(),
+                version: 1,
+                arg_slots: 0,
+                ret_slots: 1,
+            },
+            SyscallDecl {
+                module: "system".into(),
+                name: "has_cart".into(),
+                version: 1,
+                arg_slots: 0,
+                ret_slots: 1,
+            },
+        ];
+
+        let data = module.serialize();
+
+        assert_eq!(BytecodeLoader::load(&data), Err(LoadError::DuplicateSyscallIdentity));
     }
 }
diff --git a/crates/console/prometeu-bytecode/src/program_image.rs b/crates/console/prometeu-bytecode/src/program_image.rs
index 7dd95b3b..c3293dd8 100644
--- a/crates/console/prometeu-bytecode/src/program_image.rs
+++ b/crates/console/prometeu-bytecode/src/program_image.rs
@@ -118,6 +118,7 @@ impl From<ProgramImage> for BytecodeModule {
             code: program.rom.as_ref().to_vec(),
             debug_info: program.debug_info.clone(),
             exports,
+            syscalls: Vec::new(),
         }
     }
 }
diff --git a/crates/tools/pbxgen-stress/src/lib.rs b/crates/tools/pbxgen-stress/src/lib.rs
index 632a2d97..8501d834 100644
--- a/crates/tools/pbxgen-stress/src/lib.rs
+++ b/crates/tools/pbxgen-stress/src/lib.rs
@@ -38,6 +38,7 @@ pub fn generate() -> Result<()> {
             function_names: vec![(0, "main".into())],
         }),
         exports: vec![Export { symbol: "main".into(), func_idx: 0 }],
+        syscalls: vec![],
     };
 
     let bytes = module.serialize();
diff --git a/docs/pull-requests/PR-2 - PBX SYSC and HOSTCALL Loader Patching.md b/docs/pull-requests/PR-2 - PBX SYSC and HOSTCALL Loader Patching.md
index f3a17166..f84f5f1b 100644
--- a/docs/pull-requests/PR-2 - PBX SYSC and HOSTCALL Loader Patching.md	
+++ b/docs/pull-requests/PR-2 - PBX SYSC and HOSTCALL Loader Patching.md	
@@ -268,6 +268,124 @@ Required behavior:
 
 - patch before `Verifier::verify(...)`
 
+## Implementation Plan
+
+Implementation should be staged so each phase leaves the workspace in a coherent state and keeps the verifier/VM contract intact.
+
+### Commit Checklist
+
+1. `prometeu-bytecode: add SyscallDecl model and mandatory SYSC section`
+2. `prometeu-bytecode: add SYSC parser validation and load errors`
+3. `prometeu-bytecode: add phase-1 coverage for empty/valid/invalid SYSC`
+4. `prometeu-bytecode: wire downstream constructors to new BytecodeModule.syscalls field`
+5. `prometeu-bytecode: clean up naming/docs after phase-1 passes`
+
+### Phase 1 - Extend PBX module format
+
+Target crates:
+
+- `crates/console/prometeu-bytecode`
+
+Steps:
+
+1. add `SyscallDecl` to `src/model.rs` and extend `BytecodeModule` with `syscalls: Vec<SyscallDecl>`
+2. reserve a new section kind for `SYSC` in module serialization/deserialization
+3. enforce the mandatory-section rule: valid PBS images always carry `SYSC`, including `count = 0`
+4. reject malformed payloads, invalid UTF-8, and duplicate canonical identities during load
+5. update `src/lib.rs` exports if needed so the VM and HAL can consume the new declarations
+
+Checkpoint:
+
+- `BytecodeLoader::load(...)` returns `BytecodeModule` with canonical syscall declarations preserved from PBX
+
+### Phase 2 - Add pre-load opcode support
+
+Target crates:
+
+- `crates/console/prometeu-bytecode`
+
+Steps:
+
+1. add `HOSTCALL` to `src/opcode.rs` with a `u32` immediate
+2. extend `src/opcode_spec.rs` and `src/decoder.rs` so the loader can scan and decode `HOSTCALL`
+3. update `src/assembler.rs` and `src/disassembler.rs` so tests and fixtures can produce/read pre-load artifacts
+4. keep the runtime contract explicit: `HOSTCALL` is representable in bytecode artifacts but must not survive loader patching
+
+Checkpoint:
+
+- bytecode tooling round-trips `HOSTCALL <index>` correctly, while runtime execution still depends on patched `SYSCALL <id>`
+
+### Phase 3 - Bridge PBX declarations to host metadata
+
+Target crates:
+
+- `crates/console/prometeu-hal`
+
+Steps:
+
+1. add a resolver path that accepts program-owned syscall declarations instead of only `&'static str` identities
+2. resolve each `(module, name, version)` against `src/syscalls.rs`
+3. validate `arg_slots` and `ret_slots` against authoritative `SyscallMeta`
+4. validate required capabilities against cartridge-derived `CapFlags`
+5. return deterministic, load-facing errors for unknown syscalls, ABI mismatches, and missing capabilities
+
+Design note:
+
+- this phase likely needs a small owned-string adapter or a new helper alongside `resolve_program_syscalls(...)`, because PBX strings are runtime data, not `&'static str`
+
+Checkpoint:
+
+- given only `BytecodeModule.syscalls` plus granted `CapFlags`, the loader can produce a resolved table `sysc_index -> syscall_id`
+
+### Phase 4 - Patch before verification
+
+Target crates:
+
+- `crates/console/prometeu-vm`
+
+Steps:
+
+1. add a load-time patching helper near `src/virtual_machine.rs` or a small dedicated module
+2. run that helper immediately after `BytecodeLoader::load(...)` and before `Verifier::verify(...)`
+3. scan `module.code`, decode every instruction, and rewrite `HOSTCALL <index>` into `SYSCALL <resolved_id>`
+4. reject out-of-bounds `HOSTCALL` indices during the scan
+5. track `SYSC` usage and reject declarations that are never referenced
+6. assert that no `HOSTCALL` remains before handing code to the verifier
+7. only then call `Verifier::verify(...)`, compute `max_stack_slots`, and build `ProgramImage::from(module)`
+
+Why the sequencing matters:
+
+- the current load path in `crates/console/prometeu-vm/src/virtual_machine.rs` verifies the raw module immediately after `BytecodeLoader::load(...)`
+- `ProgramImage` currently stores only the final ROM/functions/constants and does not preserve a syscall declaration table, so patching must happen while the code is still a `BytecodeModule`
+
+Checkpoint:
+
+- the verifier sees only numeric `SYSCALL <id>` instructions, preserving the existing verifier and VM execution model
+
+### Phase 5 - Tests and failure matrix
+
+Target crates:
+
+- `crates/console/prometeu-bytecode`
+- `crates/console/prometeu-hal`
+- `crates/console/prometeu-vm`
+
+Steps:
+
+1. add serialization/deserialization tests for missing, empty, valid, malformed, and duplicate `SYSC`
+2. add opcode tests for `HOSTCALL` decoding and assembler/disassembler coverage
+3. add resolver tests for unknown identity, ABI mismatch, and capability mismatch
+4. add VM load-path tests proving patch-before-verify behavior
+5. add an assertion that final executable images contain only numeric `SYSCALL`
+
+Suggested PR slicing:
+
+1. bytecode format + tests
+2. `HOSTCALL` opcode plumbing
+3. HAL resolution/ABI validation
+4. VM loader patching
+5. integration and regression tests
+
 ## Deterministic Load Errors
 
 Load must fail for at least:
diff --git a/test-cartridges/stress-console/program.pbx b/test-cartridges/stress-console/program.pbx
index aec099eb..ed965b6a 100644
Binary files a/test-cartridges/stress-console/program.pbx and b/test-cartridges/stress-console/program.pbx differ