C Adapter

The C adapter provides a stable C ABI over the Rust adapter runtime.

Build

cd Build
cargo build -p saikuro-c

Output libraries are produced in Cargo target directories (for example libsaikuro_c.a and libsaikuro_c.so on Linux).

Header

• Build/adapters/c/include/saikuro.h

API model

• saikuro_client_t: connect, call, cast, batch, stream, channel, and resource invocation
• saikuro_stream_t: read stream items as JSON
• saikuro_channel_t: send/receive channel JSON frames
• saikuro_provider_t: register C callbacks and serve a namespace

Capability parity

Ownership and safety

• Pointer-returning APIs return NULL on failure
• Integer-returning APIs return non-zero on failure
• Use saikuro_last_error_message() for diagnostics
• Free adapter-owned returned strings with saikuro_string_free()
• Provider callbacks must return heap-allocated JSON strings created with saikuro_string_dup()

Ownership-safe callback example

static char *sum_cb(void *ctx, const char *args_json) {
	(void)ctx;
	(void)args_json;
	return saikuro_string_dup("42");
}

The callback return value is owned by the adapter runtime after return. Do not return stack pointers or string literals.

Useful APIs

• saikuro_client_batch_json(...)
• saikuro_client_stream_json(...) + saikuro_stream_next_json(...)
• saikuro_client_channel_json(...) + saikuro_channel_send_json(...)
• saikuro_client_resource_json(...)
• saikuro_client_log(...)

Next Steps

• C++ Adapter: RAII wrapper over the C ABI
• C API Reference: Stable ABI function and handle reference
• C examples: C ABI usage and ownership patterns
• Code Generation: Generate C-compatible clients from schema