What evidence suggests that there was a trade between Harappa and Sumer?

Archaeological findings of Harappan seals in Mesopotamia and Sumerian artifacts in the Indus Valley indicate a trade relationship between the two civilizations. These seals were used for marking goods in trade, suggesting a commercial exchange between the cities. Additionally, excavations at various sites have revealed evidence of Harappan products such as pottery and beads in Mesopotamia, further supporting the existence of trade between Harappa and Sumer.