[Bug Fix] Guard tool call name and id against null stream deltas in llm-deepseek

[kolawong]

Problem

When connecting to OpenAI-compatible gateways and proxies (such as OpenCode, LiteLLM, OneAPI, etc.), tool call streaming deltas conform to the standard OpenAI SSE shape where the first chunk specifies { name: "tool_name", arguments: "" }, and subsequent argument chunks send { name: null, arguments: "..." }.

In packages/llm/llm-deepseek/src/translate.ts:

if (call.function?.name !== undefined) block.name = call.function.name

Because null !== undefined is true in JavaScript, the valid tool name captured from chunk 1 was being overwritten by null in chunk 2, causing the assembled tool call to have name: "" (empty string), leading to runtime Error: unknown tool "".

---

Solution & Commit

A patch with unit tests has been pushed to the fork:
👉 Commit: kolawong@1aa1af2571
👉 Branch: https://github.com/kolawong/deepseek-harness/tree/fix/llm-deepseek-null-tool-delta

• Checked typeof call.function?.name === 'string' && call.function.name.length > 0 before updating block.name.
• Checked typeof call.id === 'string' && call.id.length > 0 before updating block.callId.
• Added unit test in packages/llm/llm-deepseek/tests/translate.spec.ts covering SSE chunks with { name: null, id: null } (31/31 Vitest tests passed).

Please consider cherry-picking this fix into master. Thank you!

[weijiafu14]

A usable alternate path is to let a transport-owning Pi provider parse the proxy's SSE instead of routing it through the affected dsh-llm-deepseek translator. pi-provider-litellm can be installed with pi2dsh and becomes a normal DSH model route:

dsh plugin --profile web add pi2dsh
dsh plugin --profile web add pi-provider-litellm
export LITELLM_BASE_URL="<your LiteLLM/OneAPI/OpenAI-compatible gateway root>"
export LITELLM_API_KEY="<your key>"
# restart dsh and select that route

I checked the implementation before posting: the package owns a createProvider + openAICompletionsApi transport; Pi accumulates tool calls by stream index and updates the stored id/name only for non-empty incoming values; pi2dsh recognizes streamSimple, registers it through DSH llm.registerAdapter, and forwards the finalized non-empty tool identity. Thus continuation chunks containing null cannot erase the first valid name/id.

I do not have the gateway deployment used in this report, so this is a source-audited compatibility route rather than a live claim for that account. If it still fails on your endpoint, please send the redacted error/stream shape to https://github.com/weijiafu14/pi2dsh/issues and I will trace and fix the concrete incompatibility.