Perplexity vs LangGraph

Almost the entire release stream is persistence work spread across four packages: langgraph, checkpoint, checkpoint-postgres and checkpoint-sqlite. The delta channel, the incremental checkpoint mechanism, has produced correctness fixes in every release from 1.2.6 through 1.2.10 and into checkpoint 4.2.0. New in this window are an opt-in omit_expired flag that skips expired rows on read, and a conformance suite that runs the same tests against both the Postgres and SQLite backends.

The graph runtime itself looks settled; the money is going into making storage backends behave identically and into controlling how much state gets read back. A conformance suite is what you build once you have multiple backends quietly drifting apart, and running it across Postgres and SQLite together suggests that drift was real. The tracing API is the unsettled edge: TracePolicy was exposed on add_node, had tags dropped, was deleted and then reverted, all inside 1.2.10.

Expect the conformance suite to pull additional checkpoint backends under the same tests, and omit_expired to graduate from opt-in once its read semantics have been exercised. The TracePolicy churn suggests the tracing surface gets another pass before it stabilizes.