// STRYKE-GRPC — ENGINEERING REPORT

>_EXECUTIVE SUMMARY

stryke-grpc is one of the opt-in connector packages in the stryke ecosystem. Generic, reflection-based gRPC client for stryke — list services, describe methods, call unary and streaming RPCs with JSON in/out. Like grpcurl but as a stryke package: it ships as a Rust cdylib that stryke dlopens in-process on first use Grpc.

Reflection-driven means no .proto files needed on the client side. Targets that expose the gRPC reflection service work out of the box.

~ARCHITECTURE

In-process cdylib design: the stryke side is a thin .stk wrapper that calls FFI symbols on the dlopen'd library. No subprocess, no pipe — calls return on the same thread that made them.

$WHY OPT-IN (NOT BUILTIN)

Reflection-driven means no .proto files needed on the client side. Targets that expose the gRPC reflection service work out of the box.

The trade-off is intentional. The core stryke binary stays under ~40 MB precisely because each connector ships separately. Daily-driver work (one-liners, awk replacement, data scripting) doesn't need MongoDB drivers, AWS SDKs, or Spark Connect bindings linked in.

&FFI ENVELOPE

JSON in / JSON out across the FFI boundary. Each Grpc::* wrapper serializes its args to a JSON dict and calls the matching grpc__* symbol; the cdylib returns a JSON CString the wrapper parses. catch_unwind on every call converts panics to JSON errors. The returned CString is freed via the cdylib-exported stryke_free_cstring, wired automatically by rust_ffi::load_cdylib.

# request shape (built by the .stk wrapper)
{"...": ...}

# response shape
{"result": ...}            # success — per-fn shape
{"error": "<msg>"}        # failure — wrapper die()s with Grpc::<op>: <reason>

@FFI EXPORT INVENTORY

The cdylib exports 46 grpc__* symbols (the [ffi].exports array in stryke.toml). 8 are RPC verbs that open a channel; the other 38 are pure, connection-free wire helpers that parse / build / validate gRPC HTTP/2 metadata, status, target, timeout, content-type, user-agent, compression, and framing primitives. The Grpc.stk wrapper exposes a matching 46 public Grpc::* functions one-to-one.

%REFLECTION PIPELINE

No .proto files live on the client. On every list / describe / call, src/reflection.rs talks to grpc.reflection.v1alpha.ServerReflection to build the descriptor graph at call time:

The grpc.reflection.v1alpha client is generated at build time by build.rs (tonic-prost-build compiling proto/reflection.proto, client-only).

+DEPENDENCIES

The connector pulls in the tonic / prost / tokio gRPC stack — the reason it is opt-in rather than linked into core stryke.

Release profile: opt-level = 3, lto = "thin", codegen-units = 1, strip = true, panic = "abort".

/SCOPE

The package is intentionally narrower than the underlying tonic SDK — the goal is "useful from a shell pipeline", not "complete API coverage". See the README's "Why this is a package" + "API reference" sections for the authoritative scope.

#PROJECT METADATA