@hy-sde-org/dsh-llm-slots

Host-wide model-slot admission control (ctx.modelSlots) for the DeepSeek Harness. A deployment that runs a handful of concurrent model providers behind one local inference endpoint (typically 2–3 slots, ~1M context each) needs an explicit budget over every model call — otherwise the main agent's turns, running subagents, and workflow fan-out stack dozens of simultaneous bursts against the endpoint and every call slows to queue latency.

Published standalone as @hy-sde-org/dsh-llm-slots; it mirrors @deepseek-ai/dsh-llm-slots in the hy-sde deepseek-harness fork (the fork-only package is not on npm and not in upstream stock).

How it works

• One chokepoint. Admission decides FIFO at the llm/stream waterfall — the single boundary every model-backed call crosses (main agent loops, in-process subagents, worker-thread children, workflows, title/compaction side-requests), regardless of which session or context initiated it.
• Host-global budget. The gate lives in module scope, so every derived context and plugin instance shares one pool. Capacity is configured on the llm-slots row (default 3) and adjustable at runtime: ctx.modelSlots.setCapacity(n).
• Cancellable waits. A call waiting for a slot observes its AbortSignal; cancellation while queued surfaces as an AbortError upstream and never receives a freed slot.
• One slot per logical call. A call holds its slot for its full lifetime, including adapter retries, which also prevents a failing endpoint from fanning out an unbounded retry storm.

Composition

Mount once per host in a shared-row composition:

- id: llm-slots
  name: '@hy-sde-org/dsh-llm-slots'
  config:
    enabled: true
    capacity: 3

Additional mounts share the same global budget and are safe but redundant.

Service surface

ctx.modelSlots exposes:

• stats() — { enabled, capacity, running, waiting, acquiredTotal }.
• setEnabled(boolean) — toggle admission without touching capacity.
• setCapacity(number) — change the budget; a shrink applies as calls drain.

The optional ./invariant entry registers package-owned admission-accounting checks with a Cordis host's ctx.invariants service and needs @deepseek-ai/cordis + @deepseek-ai/dsh-invariants peers only when you use that entry.

Development

pnpm install
pnpm -r check       # strict typecheck (src + tests)
pnpm -r test        # gate + admission tests
pnpm -r build       # tsc -> dist

No model-facing tools ship here; the package deliberately reads no LLM service state (it only listens on the shared event bus), which keeps it trivially testable and safe to mount in any context.

Known Limitations and Deferred Work

• The gate is process-global: capacity is not partitioned per provider or per session, and the budget never drains below what in-flight calls hold (a shrink takes effect as calls finish).
• acquire() grants one slot per logical call; there is no priority or fair-share scheduling beyond arrival order (FIFO).

License

MIT. Derived from the DeepSeek Harness codebase; see THIRD-PARTY-NOTICES.md for provenance.