@dsh-lattice/adapter-dsh

DSH Lattice V1 provider adapter for the DeepSeek Harness public seam.

This package is an independent community adapter, part of the DSH Lattice facade project. It is not affiliated with, endorsed by, or sponsored by DeepSeek AI, and it does not import the upstream @deepseek-ai/dsh-root package.

What it provides

Module	Responsibility
capabilities	Capability detection: required-vs-observed comparison that fails loud (ECC-V1.0 §12, §22.2)
session-mapping	Canonical agentId ↔ session mapping, identity kinds, explicit SessionLink lineage, compatibility fingerprints (§10, §16.3)
events	Lattice/audit events with REQUIRED tenantId, secret redaction <redacted:kind/name>, leak scan (§19.3, §19.4)
manifest	Adapter manifest validation; credentialRef references only — values are never inlined (§12, §19.3)
adapter	DshAdapter implementing the Lattice adapter contract over a minimal SubagentsSeam

Quick start

import { createDshAdapter } from "@dsh-lattice/adapter-dsh";

const adapter = createDshAdapter({
  id: "dsh-sdk",
  descriptor: {
    name: "dsh-sdk",
    package: "@dsh-lattice/adapter-dsh",
    adapterVersion: "1.0.0",
    requiredCapabilities: ["continuation", "directMessage", "structuredOutput", "progress"],
    observedCapabilities: ["continuation", "directMessage", "structuredOutput", "progress", "oneShot"],
    credentialRef: { kind: "env", name: "DSH_SDK_TOKEN" },
  },
  seam: harnessCtx.subagents, // the live ctx.subagents object
});

// Fail-loud gate before a run starts:
const preflight = adapter.preflight(["continuation", "artifacts"]);
if (!preflight.ok) {
  // capability_mismatch: missing [artifacts]
}

const envelope = await adapter.runOneShot({
  prompt: "review this diff",
  tenantId: "tenant_1",
  runId: "run_1",
  taskId: "tsk_1",
  assignmentId: "asn_1",
  idempotencyKey: "idem_...",
});

Capability detection

requiredCapabilities come from the project config; observedCapabilities come from the adapter manifest plus a runtime probe refreshed on every startup. If observed ⊉ required the adapter emits lattice/adapter/capability_mismatch and the run is rejected — never silently degraded.

Session mapping (ECC-V1.0 §10)

Provider kind	canonical agentId	lifetime
local in-process	canonical name + DSH sessionId	durable
ACP subprocess	adapter-assigned name + ACP session id	durable
A2A remote	cardId#a2aTaskId	durable
one-shot (Codex/Claude Code)	canonical name	ephemeral — run-scoped only

Identity changes (fork/resume/handoff) are recorded only via explicit SessionLink pointers — never implicit.

Security

See SECURITY.md. Highlights: no shell, capability fail-loud, credentialRef indirection (presence-only resolution), secret redaction on every event, explicit lineage.

Upstream compatibility evidence

Facts below were checked against the upstream repository checkout in this workspace (deepseek-harness/, as of this writing):

• Upstream package is @deepseek-ai/dsh-root 0.1.0-rc.5, "type": "module", pnpm-managed, and is Cordis-based (scripts verify-cordis-config, gen-cordis-catalog, gen-cordis-api; cordis.patch.yml files in packages/bundle/*).
• The harness context exposes ctx.subagents with registerProvider(...), start(providerId, options), startContinuable(...), interrupt(...), and listChildren(...) (see packages/sdk/server/tests/server.spec.ts, packages/subagent/subagent/README.md, and the subagent capability-seam notes). DshAdapter depends only on this documented subset via the SubagentsSeam interface, so it can be wired to a real harness context without a hard upstream dependency.
• send_message / interrupt_agent are parent-child limited. The tools live in packages/subagent/tool-subagent-control/src/index.ts; list_agents documents that only depth-1 direct children are send_message candidates and deeper entries are interrupt_agent-only. The Lattice agent_message shim preserves this constraint (see the aggregator package).
• The upstream SDK protocol client frames JSON-RPC 2.0 as one compact JSON frame per \n-terminated line (packages/sdk/protocol/README.md) — this is the framing the @dsh-lattice/transports ACP client mirrors.
• Upstream ships an MCP client, not a public MCP server; the exactly-one-tool MCP server in @dsh-lattice/transports is therefore a Lattice-owned boundary, not an upstream feature.

What is NOT verified

• No real DeepSeek Harness provider was launched in this workspace (no credentials, and upstream is developer preview). The seam contract is compile-time verified against the documented API subset, not executed against a live harness runtime.
• Protocol versions (MCP/ACP/A2A) are pinned per release manifest; re-verify before publishing (ECC-V1.0 §22.3).

Development

pnpm install          # offline-capable from the pnpm store
pnpm build            # tsc → dist/
pnpm typecheck
pnpm test             # vitest
pnpm coverage

License

Apache-2.0. See LICENSE and NOTICE.