The global collective term for Anomaly authority agencies. Narrowly, the Circle refers to the five major public authorities: the Bureau of Anomaly Control, Yggash Court, Celaeno Compound, Zerogon Laboratory, and Ghroth Island, along with Supreme Tribunal A6. More broadly, however, the Circle also includes various civilian Anomaly Hunter organizations and individual Anomaly Hunters.

The Circle operates on the 3C philosophy: Control, Containment, and Cognition. Among the five major authorities, the Bureau of Anomaly Control corresponds to Control. The Celaeno Compound, which houses contained Anomalies, and Ghroth Island, which operates as a prison, correspond to Containment. Yggash Court, responsible for intelligence, and Zerogon Laboratory, which leads research efforts, correspond to Cognition More broadly, however, the Circle also includes various civilian Anomaly Hunter organizations and individual Anomaly Hunters