deepseek-ai/deepseek-harness · error · Error

dsh-tools: mode "${mode}" requires a code runtime — load a c

Error message

dsh-tools: mode "${mode}" requires a code runtime — load a ctx.codeRuntime implementation (e.g. @deepseek-ai/dsh-code-runtime-worker-thread) or set tools mode to "native"

What it means

Error "dsh-tools: mode "${mode}" requires a code runtime — load a ctx.codeRuntime implementation (e.g. @deepseek-ai/dsh-code-runtime-worker-thread) or set tools mode to "native"" thrown in deepseek-ai/deepseek-harness.

Source

Thrown at packages/core/tools/src/index.ts:1022

   * Resolve the code runtime or throw the actionable misconfiguration error.
   * Read at use time (assembly / run_code execution), NOT via static
   * `inject`: an inject entry would hold `ctx.tools` — and every tool plugin
   * behind it — hostage to a code runtime existing even under `mode:
   * 'native'` (the loop's optional-backend idiom, same as
   * `sessionPersistence`).
   *
   * Assembly and `run_code` execution read separately, so the language is not
   * bound to a request. Harmless while one published backend exists — both
   * reads return the same flavor — but a reload that swapped in a second
   * language between them would hand a program written against one SDK to the
   * other. Binding it is deferred until a second backend ships (the first
   * point it is testable); rationale in the
   * [language-dispatch note](../../../../.agents/notes/implemented/feature/2026-07-31-code-mode-language-dispatch.md).
   */
  private requireCodeRuntime(mode: ToolPresentationMode): CodeRuntime {
    const runtime = this.ctx.get('codeRuntime')
    if (!runtime) {
      throw new Error(`dsh-tools: mode "${mode}" requires a code runtime — load a ctx.codeRuntime implementation (e.g. @deepseek-ai/dsh-code-runtime-worker-thread) or set tools mode to "native"`)
    }
    if (!Object.hasOwn(SDK_RENDERERS, runtime.language)) {
      const known = Object.keys(SDK_RENDERERS).map(name => JSON.stringify(name)).join(', ')
      throw new Error(`dsh-tools: no SDK renderer registered for runtime language ${JSON.stringify(runtime.language)} (known: ${known})`)
    }
    return runtime
  }

  /**
   * Register globally or in the calling agent scope. Scoped tools shadow
   * globals; duplicates within one layer and the reserved `run_code` name fail.
   * @param definition - tool schema, execution, and optional finalization/presentation callbacks.
   * @returns the exact disposer that unregisters the tool.
   */
  register(definition: ToolDefinition): () => void {
    const name = definition.name
    const output = (definition as Partial<ToolDefinition>).output
    if (output === undefined || typeof output !== 'object'

View on GitHub (pinned to b150a551b8)

When it happens

Trigger: Thrown at packages/core/tools/src/index.ts:1022 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of deepseek-ai/deepseek-harness@b150a551b8 (2026-08-24). Data as JSON: /api/errors/aa43c1fe3d1fba33. Report an issue: GitHub.