A modular in-line drip emitter may include a flow restrictor and a replaceable attachment. The flow restrictor may provide fluid communication between an inlet and a fluid outlet chamber. The flow restrictor may include rate limiting fluid path producing a predefined range of flow rate over a predefined pressure differential range between the fluid inlet and the fluid outlet. The attachment may be sized and shaped to mount to the flow restrictor. In some embodiments the attachment includes an inlet opening oriented for receiving fluid from a conduit and a fluid outlet attachable to the fluid inlet of the flow restrictor. In some embodiments the attachment includes a sleeve fitting into a conduit with an annular outlet chamber attachable to the outlet chamber of the flow restrictor.