RFC 0011: MetaCall Client API Support (`metacall()`)

Implementation Notes

Implemented as designed with these notes:

metacall_handle is excluded because argument layout varies per port (tag first in C/Node, handle first in Rust).
Phase A and Phase B index all extracted symbols regardless of visibility flag.
Rust metacall_no_arg and metacall_untyped map to ClientCall; load::from_single_file maps to LoadFromFile.
Client-call reference edges flow as distinct inter-pod reference edges without altering load confidence.

1. Problem

The deploy scanner previously detected only metacall_load_from_* calls. Client function calls were not tracked:

from metacall import metacall_load_from_file, metacall

metacall_load_from_file('node', ['auth/auth.js'])

def encrypt(text):
    return metacall('sign', text) # Untracked client call

Without client call tracking, Function Mesh topology missed function-level cross-language dependencies and call-site attribution.

2. API Surface

The scanner detects client invocation APIs across all supported ports:

API	Ports	Target
`metacall(name, ...)`	py, node, C, C++, Rust, Go	function name string
`metacall_await(name, ...)`	node, C, Go	function name string
`metacallfms(name, buffer)`	node	function name string
`metacallv(name, args[])`, `metacallt(...)`	C	function name string
`metacall_function(name)`	C	function name string
`metacall::metacall`, `metacall_no_arg`, `metacall_untyped`	Rust	function name string
`metacall.Call(...)`, `metacall.Await(...)`	Go	function name string

3. Design

3.1 Model

CallSite includes ClientCall variant fields:

#![allow(unused)]
fn main() {
pub enum CallSiteVariant {
    LoadFromFile,
    LoadFromMemory,
    LoadFromPackage,
    LoadFromConfiguration,
    ClientCall,
}

pub struct CallSite {
    pub function_name: Option<String>,
    pub is_async: bool,
    // existing fields...
}
}

3.2 Two-Phase Function Resolution

client_call::resolve_client_calls resolves target functions:

Phase A (Load-aware): Matches call names against public symbols in files explicitly loaded by the calling file. Matches score 1.0 (unique) or 0.8 (ambiguous).
Phase B (Global fallback): Searches all project symbols if Phase A finds no match. Matches score 0.6 (unique) or 0.5 (ambiguous).
Computed names: Dynamic arguments cap edge confidence at 0.4. Unresolved names produce a Warning diagnostic.

Client-call edges are EdgeKind::Reference from calling file node to target symbol node. They participate in SCC analysis before pod partitioning, ensuring cross-language call cycles create proper cuts.

4. Impact

metacall.pods.json: Includes reference edges for cross-language client calls.
metacall.mesh.json: cross_language_edges attributes target deployment units and call-site files.

meta-ast