Frontend Engineering at Palantir: Building a Backend-less Cross-Application API

Summary

Palantir’s Application Frameworks team builds the “backend of the frontend”: frameworks that let applications communicate during workflows spanning multiple interfaces. The work addresses environments with denied, disrupted, intermittent, or limited (DDIL) connectivity, where relying on backend services can introduce unreliable latency. The team generalized the Gaia Controller prototype into Shared State, which lets applications define named data models and exchange updates organized by Media Type, and Commands, which exposes arbitrary logic through command IDs and request objects that return responses. Both frameworks use frontend-only browser APIs for client-side interaction, support workflows such as pairing Gaia with Workshop, and are also being used as tools by AIP agents; the post says adoption is growing across Palantir.

Takeaways

1. 1

   Shared State synchronizes application data by allowing apps to define a data model and name, then send and receive updates organized by a Media Type string.

2. 2

   Commands exposes arbitrary application logic for cross-application invocation; callers provide a command ID and request object, and the framework returns the response.

3. 3

   Client-side communication avoids depending on backend latency, supporting side-by-side Gaia and Workshop workflows and AIP agents that use Commands and Shared State as tools.