siftwise blogIntroducing siftwise · Part 3 of 10
What siftwise is
siftwise is self-hosted test selection plus failure triage, for CI and for coding agents. It records every CI test result in your own Postgres, with no test instrumentation; selects the tests a change can affect, each with a reason; gives each failure a verdict with its evidence; and measures its own misses in shadow mode. Apache-2.0.
It ships as a light CLI (pip install siftwise), three GitHub composite actions,
an MCP server (siftwise mcp), and an API server published as a Docker image.
Import graphs are computed by the client, in the checkout, so the server never needs your
source code.
It fails open. An unreachable server, a timeout, an HTTP error or a
missing token makes select run the full suite and record/rollup
log a warning. A siftwise outage never blocks CI. The one exception is fail-on,
which you opt into, and which then fails closed, so an outage can't let a regression
through.