DeepSeek Chat Completion

Wraps DeepSeek's chat/completions endpoint in the same subprocess-invocation shape as the other ruflo-*-harness skills (see ruflo-metaharness's harness-score for the reference). No library import on ruflo's boot path.

When to use

• You want a cheap, fast completion from a non-reasoning model.
• The task fits in a single request/response — no multi-turn context.
• You want the raw content back as JSON so downstream tooling can consume it.
• For reasoning-heavy tasks (proofs, multi-step planning, hard debugging), use deepseek-reason instead — same plugin, different model.

Algorithm

Implementation: scripts/chat.mjs.

1. Read DEEPSEEK_API_KEY from env. If missing, emit { status: 'degraded', reason: 'DEEPSEEK_API_KEY is not set', ... } and exit 0 (ADR-150-style graceful degradation).
2. POST to https://api.deepseek.com/v1/chat/completions with { model, messages, temperature?, max_tokens? }. 60s hard timeout.
3. Extract choices[0].message.content and usage counters.
4. --format table prints only the content (for piping); --format json (default) returns the full envelope.
5. --alert-on-error exits 1 on any degraded/error status (CI-friendly).

Example

node plugins/ruflo-deepseek-harness/scripts/chat.mjs \
  --prompt "In one sentence: what is HNSW?" \
  --temperature 0.2

Sample output:

{
  "status": "ok",
  "model": "deepseek-chat",
  "content": "HNSW is a graph-based approximate nearest neighbor …",
  "finishReason": "stop",
  "usage": { "promptTokens": 12, "completionTokens": 34, "totalTokens": 46 }
}