processfork-sglang 1.0.3

ProcessFork plugin for SGLang ≥0.5 — RadixAttention prefix-share preserved across snapshot/restore.

processfork-sglang

ProcessFork plugin for SGLang ≥0.5. Snapshot / fork / checkout endpoints that preserve RadixAttention prefix-sharing across restores.

Install

pip install "processfork-sglang[sglang]"

Use

python -m sglang.launch_server \
  --model meta-llama/Llama-3-8B \
  --plugin processfork \
  --deterministic-mode

Endpoints (matching the vLLM plugin's surface):

POST /processfork/snapshot
POST /processfork/fork
POST /processfork/checkout
POST /processfork/merge

The plugin maps SGLang's mem_pool.req_to_token_pool onto the paged-batchinvariant-v1 LogicalSeq array, so prefix-sharing survives across snapshot/restore.

Bit-exact restore requires --deterministic-mode.

Status

The trait surface and wire format are stable. The live FFI shim into sglang.srt.mem_cache.RadixCache lands in v1.0.1 alongside the vLLM adapter. Until then, the plugin's HTTP surface returns 501 with a clear pointer to this README.