Saman

If there were such a thing as a capital city of Hewellen territory, Saman would be it. In fact it's nothing more than a trading site, where Hewellen gather every three years to trade goods, resources, and information. While this is going on, Saman is a bustling metropolis; inbetween these occasions, Saman has very few inhabitants and very little happens there.
What Saman does host year round are the Longrunes, sometimes called the Saman line. This is a switchboard-like system of communication, using a variation of paired Speaking Stones. Each Hewellen artificer carries one half of the pair; their opposite numbers are all in Saman. Thus an artificer can message Saman once per day, who can then message back the next day.
These messages are written in runes, and can only be very brief. Still, the communication it allows is a major reason why Hewellen culture is dominant in the Forges.
The method is referred to as Longrunes after the distance the inscribed runes encompass. The stones used for this are composed of tuff, lithified volcanic ash, which is soft and easy to work. Runes are etched into the stone, which simultaneously appear in the twin "listening" stone; they disappear when the message is read. Though this technically "heals" the stone back to its pre-etched state, in fact a pair of longrune stones has about 30 uses in it before it is weakened and crumbles to dust. Since artificers of 2nd level or higher can all replicate the sending stones spell, any Hewellen artificer can replace their own longrune stones, and are expected to—and then they need to get one half of the pair to Saman.
The widespread guild-like group called the Tinkers, being composed largely of Hewellen and Hewellen-trained artificers, are all technically part-time spies for the Hewellen, though they would never think of it that way.