> For clean Markdown of any page, append .md to the page URL. > For a complete documentation index, see https://docs.nvidia.com/skills/skillevaluator/llms.txt. > For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.nvidia.com/skills/skillevaluator/_mcp/server. # Environment Variables > The complete reference of every environment variable SkillEvaluator reads — providers, embeddings, validation, and live evaluation. Every environment variable SkillEvaluator reads, grouped by feature area. Each group links to the guide that explains the workflow the variables belong to — this page is the inventory, not the tutorial. Boolean variables accept `1`, `true`, `yes`, or `on` (case-insensitive) as true, and `0`, `false`, `no`, or `off` as false. Two historical SkillEvaluator prefixes coexist. `SKILL_EVAL_*` covers provider and model configuration plus a small set of Tier 3 engine knobs; `SKILLEVALUATOR_*` covers product-level validation, report paths, scanner paths, and sandbox/runtime behavior. The prefixes are part of each variable's literal public name and are not interchangeable. The separately documented `SKILLSPECTOR_*` family belongs to SkillSpector, provider credential families belong to their providers, and [Harbor](https://github.com/harbor-framework/harbor), the open-source agent evaluation framework used for Tier 3, owns the `HARBOR_*` in-container grader contract. None belongs to either SkillEvaluator prefix. ## LLM provider These variables select and configure the provider used for LLM-backed checks and judging. The setup walkthrough, including per-provider export blocks and default models, is in [Providers & Credentials](/skills/skillevaluator/configuration). | Variable | Default | Effect | | ------------------------------------------------------------------------------------- | --------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `SKILL_EVAL_LLM_PROVIDER` | auto-selected (see below) | Provider for chat and judging: `openai`, `anthropic`, `nv_build`, `bedrock`, or `openai-compatible`. | | `SKILL_EVAL_LLM_MODEL` | provider default | Chat model override. Required for `openai-compatible` — that provider has no default. Setting it to an empty string is a configuration error. | | `SKILL_EVAL_LLM_BASE_URL` | provider default endpoint | Endpoint override; takes precedence over `OPENAI_BASE_URL` and `ANTHROPIC_BASE_URL`. Required for `openai-compatible`. Ignored by `nv_build`, whose endpoint is fixed to `https://integrate.api.nvidia.com/v1` — point a custom endpoint at the `openai-compatible` provider instead. | | `SKILL_EVAL_LLM_API_KEY` | — | API key for the `openai-compatible` provider (local servers still require it to be set). | | `NVIDIA_API_KEY` | — | Credential for the `nv_build` provider (NVIDIA Build). | | `OPENAI_API_KEY` | — | Credential for the `openai` provider. | | `ANTHROPIC_API_KEY` | — | Credential for the `anthropic` provider. | | `OPENAI_BASE_URL` | `https://api.openai.com/v1` | Alternate OpenAI endpoint; `SKILL_EVAL_LLM_BASE_URL` wins when both are set. | | `ANTHROPIC_BASE_URL` | Anthropic SDK default | Alternate Anthropic endpoint; `SKILL_EVAL_LLM_BASE_URL` wins when both are set. | | `AWS_REGION` | `us-west-2` | Region for the `bedrock` provider. | | `AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY`, `AWS_SESSION_TOKEN`, `AWS_PROFILE`, ... | — | Standard AWS credential chain, used as-is by the `bedrock` provider. | ### Auto-selection When `SKILL_EVAL_LLM_PROVIDER` is unset, auto-selection only happens when exactly one public credential is exported: * `NVIDIA_API_KEY` → `nv_build` * `OPENAI_API_KEY` → `openai` * `ANTHROPIC_API_KEY` → `anthropic` If none is set, LLM-backed commands fail with a configuration error. If more than one is set, that is also a configuration error — there is no silent preference order, so set `SKILL_EVAL_LLM_PROVIDER` explicitly when multiple keys are exported. ### SkillSpector bridge The `--llm` security analysis runs [SkillSpector](https://github.com/NVIDIA/SkillSpector), which has its own provider environment. SkillEvaluator bridges your configured provider into that invocation with an isolated subprocess environment: only the selected provider's settings and a small set of basic process variables are forwarded, so ambient credentials for other providers never reach SkillSpector. The `nv_build` provider is bridged through SkillSpector's OpenAI-compatible path, pointing `OPENAI_BASE_URL` at the public NVIDIA Build endpoint. | Variable | Default | Effect | | ----------------------- | ---------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | `SKILLSPECTOR_PROVIDER` | bridged from your provider | Overrides the provider SkillSpector uses. Must name a supported public provider (`openai`, `anthropic`, `bedrock`, or `nv_build`) — only that provider's credential variables are forwarded. Any other value fails closed: SkillSpector runs without a credential. | | `SKILLSPECTOR_MODEL` | bridged from your configured model | Model SkillSpector uses for its LLM analysis. | ## Embeddings Tier 2 semantic checks use an OpenAI-compatible embeddings API. Workflow context lives in [Providers & Credentials](/skills/skillevaluator/configuration#embeddings) and [Tier 2: Deduplication](/skills/skillevaluator/tier2-deduplication). | Variable | Default | Effect | | ------------------------------- | --------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `SKILL_EVAL_EMBEDDING_PROVIDER` | falls back to `SKILL_EVAL_LLM_PROVIDER` | Embedding provider: `openai`, `nv_build`, or `openai-compatible`. `anthropic` and `bedrock` are rejected — they provide no embeddings API. | | `SKILL_EVAL_EMBEDDING_MODEL` | provider default | Embedding model override. Required for `openai-compatible`. | | `SKILL_EVAL_EMBEDDING_BASE_URL` | provider default endpoint | Embedding endpoint override; for `openai-compatible` it falls back to `SKILL_EVAL_LLM_BASE_URL`. Ignored by `nv_build`, whose endpoint is fixed to `https://integrate.api.nvidia.com/v1` — use `openai-compatible` for a custom endpoint. | | `SKILL_EVAL_EMBEDDING_API_KEY` | falls back to `SKILL_EVAL_LLM_API_KEY` | API key for `openai-compatible` embeddings. `openai` and `nv_build` use their own provider keys. | ## Validation (Tier 1) These variables tune the static and security checks. The check-by-check guide is [Tier 1: Validation](/skills/skillevaluator/tier1-validation). | Variable | Default | Effect | | ------------------------------------ | --------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `SKILLEVALUATOR_PROFILE` | `external` | Default validation profile when no `--profile` flag is passed. The CLI flag always wins. | | `SKILLEVALUATOR_BANDIT_PATH` | auto-discovered | Absolute path to the Bandit executable. | | `SKILLEVALUATOR_SEMGREP_PATH` | auto-discovered | Absolute path to the Semgrep executable. | | `SKILLEVALUATOR_SKILLSPECTOR_PATH` | auto-discovered | Absolute path to the SkillSpector executable. | | `SKILLEVALUATOR_SCHEMA_ALLOWED_DIRS` | — | Extra allowed skill-root directory names (comma- or whitespace-separated), e.g. `data,fixtures`. Additive only — names extend the built-in allowlist and never replace it. | | `SKILLEVALUATOR_SUBMITTER` | auto-detected | Explicit submitter identity for the home-path PII check. It is combined with `GITHUB_ACTOR`, `USER`, `LOGNAME`, `USERNAME`, the OS login name, and the skill's declared author — every identity that resolves is protected. If none resolves, the home-path check is disabled with a warning. | | `SKILLEVALUATOR_PREVIOUS_VERSION` | — | The previously published skill version that the opt-in version check (`--checks version`) compares against. | The scanner path overrides fail closed: a value that is not an absolute, executable file is treated as a configuration error rather than silently falling back to another same-named binary on `PATH`. This prevents a planted executable from hijacking a security scan. ## Live evaluation (Tier 3) These variables control where results land and how Harbor confines local mode. The run workflow is [Tier 3: Live Evaluation](/skills/skillevaluator/tier3-live-evaluation); execution environments are covered in [Agents & Sandboxes](/skills/skillevaluator/agents-and-sandboxes). | Variable | Default | Effect | | ----------------------------------------------------- | ---------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `SKILLEVALUATOR_RESULTS_DIR` | `/evals/results` | External root for run results. Precedence for writes: the `--results-dir` flag, then this variable, then the legacy in-skill location. Read commands (`view`, `compare`) honor the same order and also fall back to the legacy location so older runs stay visible. | | `SKILLEVALUATOR_LOCAL_SANDBOX` | `require` | Local-mode sandbox policy. `require` fails closed when no OS sandbox backend (Bubblewrap on Linux, Seatbelt on macOS) is usable; `prefer` degrades to advisory-only guardrails with a loud warning; `off` skips sandbox probing entirely — for skills you fully trust. No value enables native Windows: local mode fails closed there before anything runs — use WSL2 or `--env-mode docker`. | | `SKILLEVALUATOR_LOCAL_ALLOW_NET` | `true` | Network egress for local-mode trials. Set to `0` to airgap a skill that must not reach the network. Incompatible with the `nv_build` provider — NVIDIA Build local agents require network access, so airgapped runs are rejected up front. | | `SKILLEVALUATOR_LOCAL_STRICT_READS` | `false` | Tightens the sandbox's read-only view of the host system to a stricter path set. | | `SKILLEVALUATOR_LOCAL_INHERIT_AGENT_KEYS` | `false` | When true, local-mode trials inherit the host's agent credential variables into their ambient environment. Off by default so a hostile skill command cannot read credentials — agents and verifiers receive credentials per-exec instead. | | `SKILLEVALUATOR_RUNTIME_DIR` | `~/.local/share/skillevaluator/runtimes` | Where local mode looks for managed agent CLIs. Must be a dedicated subdirectory — not the home directory or one of its parents. | | `SKILL_EVAL_HARBOR_PREBUILD_TASK_ENVS` | unset | Set to exactly `1` to opt in to pre-building Harbor task environment images before trials start (other truthy spellings are not honored). Opt-in because concurrent trial cleanup can remove a shared prebuilt image that sibling trials still need. | | `SKILL_EVAL_JUDGE_MODEL` | falls back to `SKILL_EVAL_LLM_MODEL` | Model override for the Tier 3 dimension judge in standard grading. `LLM_JUDGE_MODEL` is honored as a higher-precedence spelling; when neither is set, the judge uses `SKILL_EVAL_LLM_MODEL`, then the built-in judge default. | | `SKILLEVALUATOR_HARBOR_DIAGNOSTIC_ARTIFACT_MAX_BYTES` | `5242880` (5 MiB) | Size cap per diagnostic artifact copied from a Harbor trial into the results directory; oversized artifacts are skipped and recorded in the artifact manifest. | ## In-container grader contract The `HARBOR_*` variables are read by your custom grader *inside* the task container — you never set them yourself, and each has a fixed in-container default. The full reward contract, with defaults and examples, lives in [Custom Graders & Tasks](/skills/skillevaluator/custom-graders). | Variable | What it carries | | -------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `HARBOR_REWARD_JSON` | Path where your grader writes its `reward.json` score. | | `HARBOR_REWARD_TXT` | Path for the compatibility `reward.txt` dual-write. | | `HARBOR_ENTRY_JSON` | Path to the eval case entry being graded. | | `HARBOR_ATIF_PATH` | Path to the agent trajectory to grade, serialized in [Agent Trajectory Interchange Format (ATIF)](https://www.harborframework.com/docs/agents/trajectory-format). | | `HARBOR_LOGS_DIR` | Root of the in-container log tree; the agent trajectory lives under its `agent/` subdirectory. | | `HARBOR_TESTS_DIR` | Directory holding the staged grader and test assets. | | `HARBOR_GRADER` | Path to the staged `grader.py`. | ## Set at runtime, not committed Keep credentials out of skill repositories and CI configuration files. Export provider keys as masked secrets at runtime. Agent credentials for Tier 3 come only from the host environment — `evals/config.yml` `runtime_env` carries non-credential values, and any entry that names or references an operator-owned credential (`OPENAI_API_KEY`, `ANTHROPIC_API_KEY`, `NVIDIA_API_KEY`, their base-URL variables, `CLAUDE_CODE_USE_BEDROCK`, and the `AWS_*` credential variables) is rejected at run time, as are names that control the host process (`PATH`, `DOCKER_*`, proxy variables, `SKILLEVALUATOR_*`, and similar). See the blocked-names table in [Providers & Credentials](/skills/skillevaluator/configuration#tier-3-credentials-two-roles). With NVIDIA Build, one exported `NVIDIA_API_KEY` covers both the evaluator and the agents in the `docker` and `local` env-modes. ## See also * [Providers & Credentials](/skills/skillevaluator/configuration) — the setup walkthrough behind the provider variables * [CLI Reference](/skills/skillevaluator/cli-reference) — the per-run flags that override many of these variables * [Gate Your CI](/skills/skillevaluator/ci-integration) — supplying these variables as masked CI secrets