credence-skin-client

The thin JSON-RPC wire client for the Credence skin — the one library external apps depend on to talk to the engine.

It ships no engine code (no juliacall, no Julia) and holds no Measures: state stays server-side as opaque IDs. A consumer of this client physically cannot do probability arithmetic, so it cannot host a brain. This is the boundary that makes the constitutional single-reasoner invariant hold by construction for any app on the other side of the wire.

Usage

Launch the engine as a pinned image and talk JSON-RPC over its stdio:

from credence_skin_client import SkinClient

skin = SkinClient(command=[
    "docker", "run", "--rm", "-i", "ghcr.io/gfrmin/credence-skin:<tag>",
])
skin.initialize(dsl_sources={"agent": "(defun choose ...)"})  # inline BDSL, no host paths
sid = skin.create_state(type="beta", alpha=1.0, beta=1.0)
skin.condition(sid, kernel={"type": "bernoulli"}, observation=1.0)
print(skin.weights(sid))
skin.shutdown()

The client pins a wire protocol major and the handshake rejects an incompatible engine with error -32010. See apps/skin/protocol.md for the full method set and the protocol changelog.

Apps declare their domain as data — dsl_sources are inline BDSL source strings; the engine never reads the host filesystem.