RPC (Remote Procedure Calls)

Request/response pattern with correlation IDs and timeouts. Call a function on another chip and get a result back.

Server Side — Register Methods

-- Register an RPC method
ic.net.register("get_status", function(payload, fromId, fromName)
    print("get_status called by " .. fromName)
    
    local temp = ic.read(0, ic.enums.LogicType.Temperature)
    local pressure = ic.read(0, ic.enums.LogicType.Pressure)
    
    -- Return value becomes the response payload
    return {
        temp = temp,
        pressure = pressure,
        uptime = os.clock()
    }
end)

-- If the handler throws, the error is sent back to the caller
ic.net.register("set_mode", function(payload, fromId, fromName)
    if type(payload) ~= "table" or payload.mode == nil then
        error("expected payload with 'mode' field")
    end
    mem_write(0, payload.mode)
    return { ok = true }
end)

-- Unregister a method
ic.net.unregister("get_status")

-- Keep alive to process incoming requests
while true do yield() end

Handlers with yield() or sleep()

RPC handlers may call yield() or sleep() before returning. The runtime resumes the handler through the RPC machinery only (not the generic user-coroutine scheduler), honors the sleep duration, and delivers the handler's return value or error to the caller when the handler finishes.

ic.net.register("slow_status", function(payload, fromId, fromName)
    sleep(2)  -- pause inside the handler; caller waits until this completes or times out
    return { ok = true, from = fromName }
end)

If the handler throws (including after a yield() or sleep()), the caller receives ok = false and err contains the message.

Client Side — Call Methods

-- Call by target name or ID
ic.net.request("ServerChip", "get_status", nil,
    function(ok, payload, err, fromId, fromName)
        if ok then
            print("Temp: " .. tostring(payload.temp))
            print("Pressure: " .. tostring(payload.pressure))
        else
            print("RPC failed: " .. tostring(err))
        end
    end,
    10  -- Timeout in seconds (default 10, max 120)
)

-- Call with parameters
ic.net.request("ServerChip", "set_mode", { mode = 3 },
    function(ok, payload, err)
        if ok then print("Mode set!") end
    end
)

-- Keep alive to receive callbacks
while true do yield() end

RPC Rules

Rule	Detail
Method name max	64 characters
Timeout	Default 10s, max 120s
Handler pauses	yield() and sleep() are allowed; return value and errors reach the caller when the handler completes
Error handling	If handler throws, ok = false and err contains the message
Timed-out requests	Silently expired (no callback)

Function Reference

Function	Returns	Description
ic.net.register(method, handler)	—	Register RPC method
ic.net.unregister(method)	—	Unregister RPC method
ic.net.request(target, method, payload, callback [, timeout])	—	Call RPC method