SDKs

The application talks to the local daemon. The daemon is the cluster member. The SDK does not join Raft and does not dial other nodes.

your process  ──►  clusdr on this host  ──►  the rest of the cluster

Same split as a local Docker engine. Two apps on one machine share one daemon.

The guide is the first call. These pages are the SDK.

Language	Install	Start here
Go	go get github.com/odurgut/clusdr/sdk	Go SDK
Python	pip install clusdr	Python SDK

CPython 3.10+. Wire package clusdr.v1alpha1.

What both SDKs do

• Local / local() — apps. Address: CLUSDR_GRPC_ADDR or 127.0.0.1:7947
• Dial / dial(addr) — tests and operators, not the default app path
• Membership, leader, Watch, Publish
• Locks and leases with a fencing token and background renew
• Retry Unavailable / Aborted / ResourceExhausted with bounded backoff
• Watch reconnects with last_seq
• On connect, wait for the Health RPC (default 10s) or fail

TLS is on unless CLUSDR_TLS=disabled. Certs: ca.crt, node.crt, node.key in CLUSDR_DATA_DIR or ~/.clusdr.

What they do not do

• Join, promote, or configure the cluster (CLI)
• Filter Watch by topic (CLI --topic exists; the SDK stream is the full bus)
• Store application data
• Talk to a remote node's Runtime API as the normal path — put a daemon on that host

Environment

Variable	Who reads it	Meaning
CLUSDR_GRPC_ADDR	Both	Runtime address. Default 127.0.0.1:7947
CLUSDR_TLS	Both	disabled / off / false / 0 → plaintext
CLUSDR_DATA_DIR	Both	Directory with PEMs. Else ~/.clusdr
CLUSDR_TLS_SERVER_NAME	Python only	TLS server name override (peer node id)

Holder

Each connection has a lock/lease identity. Empty → generated sdk-<hex>. Two apps on the same host cannot unlock each other unless they share WithHolder / holder=.