Hani are a feline-like species, maned, bearded, usually of red or tawny fur. Females are smaller than humans, males much larger (for much the same reason as Earth lions). They were discovered by the mahendo'sat and helped into space; most of their technology is therefore derived from mahen.

They live in autonomous clans, each consisting of related females, children, and a single male, the clan lord. A male takes over a clan by defeating the previous lord in personal combat. Most males are not that lucky. Male offspring are thrown out of their clan when they become strong enough to pose a threat to the lord. They live in exile among others like themselves, honing their fighting skills and waiting for the opportunity to challenge for a clan. For this reason and because males are stereotyped as being emotionally unstable, only females go into space (until Pyanfar Chanur changes the rules). Females do all the work on clan lands and in space ventures, although Cherryh does describe some able and intelligent males who become involved in the world around them.

Clans are united into amphictionies for control of scarce resources; the biggest one is their homeworld itself, governed by a mahen-inspired council of clans called the han. Hani politics are tradition-bound, based on such concepts as allegiance, honor, blood feud and parole.

One of the hani languages became the basis for the Compact's pidgin, because it was grammatically and phonetically easy for other species (but not as easy for humans).

Mahendo'sat (singular mahe) are black or brown primate-like creatures, human-size or larger. They are very curious, innovative and politically oriented. The Mahendo'sat political system is based on the concept of Personage, a charismatic figure with a lot of social credit; a Personage's power is determined by the number of its followers, but a supporter can either weaken or strengthen its Personage, depending on whether its actions in its Personage's name prove to be beneficial or not. To an outsider, this can (and frequently does) look like a Personage's mahen agents are promoting mutually contradictory policies at the same time. Mahendo'sat are idiosyncratically bad at learning other species' languages—many of them can not even master the pidgin used by Compact spacers—although they are quite eloquent in their own numerous languages. Mahendo'sat are the "glue" of the Compact, always trying to maintain the balance of power so peace can be kept and no species dominates. They are in constant search of new powers, recently including humans.

Homeworld: Llyene

Stsho are slight, slender, fragile, crested bird-like white beings (even their eyes are pearly white), xenophobic and non-aggressive. Stsho rely on wealth, trade, and alliances to keep their independence; they have devised the trade and legal procedures of the Compact. Although they are tame, stsho are great plotters and can cheat any other species. They hire other species for protection and order keeping in their stations, usually the mahendo'sat. They prefer delicate pleasures and pastel colors, their speech is exceedingly ceremonial and politically correct; they do not physically fight among themselves and their personalities are prone to change ("Phase") under stress, which has many legal implications. They have three genders, gtst, gtste and gtsto, which can change with Phasing. Only the gtst(indeterminate sex) deal with other species; the gtste and gtsto (equivalent of male and female) do not normally present themselves to foreigners. There is a fourth state of being, gtsta, which is also known as Holiness. This is a sexless state usually achieved by an aged, honorable Stsho. A Stsho who is in the process of Phasing from one state to another is gtstisi. They permit no other oxygen-breathing species in their territory.

Kif are bare-skinned, wrinkled, ash-grey, long-snouted rat-like bipedal hunters. They are the tallest species in the Compact, slender, fast and deadly. They are strictly predators, requiring live prey; they have twin sets of teeth (outer for biting and inner for pulping—their throats are unfit for swallowing solid food) and retractable claws.

Their social and political [dis]organization revolves about a quality called sfik, which combines face, authority, and ferociousness. Sfik is gained through victory in combat, or possession of something of value, or just the respect of others: followers with strong sfik give more sfik to their leader. A kif that loses sfik is likely to have its followers either defect or kill it. As a result, the kif are prone to change sides at the first sign of weakness. They seem to have no other moral values; they are pirates and cannibals, and are generally deemed troublesome by the other species.

Occasionally, a strong leader gains enough sfik to hold a base and/or command a whole fleet of ships; such a one is called a hakkikt (prince). These high status individuals are major annoyances to the mahendo'sat, who view hakkiktun as serious destabilizing factors. Very rarely, an ambitious and powerful hakkikt will aspire to become the mekt-hakkikt (supreme prince), the leader of all the kif, a status no kif has ever attained. However, by the time the Chanur cycle takes place, hakkiktun have been adding more and more power each time, each summing his predecessors' allies to his own. This has worried other species greatly, especially their eternal enemies, the mahendo'sat.

Kif are very linguistically adept and adaptable. They are also color blind and the color of their clothes and habitats are generally shades of black and grey. They use dot codes instead of color codes for their hardware.