params: { cacheRetention: "long" }, // global default provider params

agentRuntime: {

id: "pi", // pi | auto | registered harness id, e.g. codex

fallback: "pi", // pi | none

},

pdfMaxBytesMb: 10,

pdfMaxPages: 20,

- `params.chat_template_kwargs`: vLLM/OpenAI-compatible chat-template arguments merged into top-level `api: "openai-completions"` request bodies. For `vllm/nemotron-3-*` with thinking off, the bundled vLLM plugin automatically sends `enable_thinking: false` and `force_nonempty_content: true`; explicit `chat_template_kwargs` override generated defaults, and `extra_body.chat_template_kwargs` still has final precedence. For vLLM Qwen thinking controls, set `params.qwenThinkingFormat` to `"chat-template"` or `"top-level"` on that model entry.

- `compat.supportedReasoningEfforts`: per-model OpenAI-compatible reasoning effort list. Include `"xhigh"` for custom endpoints that truly accept it; OpenClaw then exposes `/think xhigh` in command menus, Gateway session rows, session patch validation, agent CLI validation, and `llm-task` validation for that configured provider/model. Use `compat.reasoningEffortMap` when the backend wants a provider-specific value for a canonical level.

- `params.preserveThinking`: Z.AI-only opt-in for preserved thinking. When enabled and thinking is on, OpenClaw sends `thinking.clear_thinking: false` and replays prior `reasoning_content`; see [Z.AI thinking and preserved thinking](/providers/zai#thinking-and-preserved-thinking).

- `agentRuntime`: default low-level agent runtime policy. Omitted id defaults to OpenClaw Pi. Use `id: "pi"` to force the built-in PI harness, `id: "auto"` to let registered plugin harnesses claim supported models, a registered harness id such as `id: "codex"`, or a supported CLI backend alias such as `id: "claude-cli"`. Set `fallback: "none"` to disable automatic PI fallback. Explicit plugin runtimes such as `codex` fail closed by default unless you set `fallback: "pi"` in the same override scope. Keep model refs canonical as `provider/model`; select Codex, Claude CLI, Gemini CLI, and other execution backends through runtime config instead of legacy runtime provider prefixes. See [Agent runtimes](/concepts/agent-runtimes) for how this differs from provider/model selection.

- `agentRuntime`: default low-level agent runtime policy. Omitted id defaults to OpenClaw Pi. Use `id: "pi"` to force the built-in PI harness, `id: "auto"` to let registered plugin harnesses claim supported models and use PI when none match, a registered harness id such as `id: "codex"` to require that harness, or a supported CLI backend alias such as `id: "claude-cli"`. Explicit plugin runtimes fail closed when the harness is unavailable or fails. Keep model refs canonical as `provider/model`; select Codex, Claude CLI, Gemini CLI, and other execution backends through runtime config instead of legacy runtime provider prefixes. See [Agent runtimes](/concepts/agent-runtimes) for how this differs from provider/model selection.

- Config writers that mutate these fields (for example `/models set`, `/models set-image`, and fallback add/remove commands) save canonical object form and preserve existing fallback lists when possible.

- `maxConcurrent`: max parallel agent runs across sessions (each session still serialized). Default: 4.

model: "openai/gpt-5.5",

agentRuntime: {

id: "codex",

fallback: "none",

},

},

},

}

```

- `id`: `"auto"`, `"pi"`, a registered plugin harness id, or a supported CLI backend alias. The bundled Codex plugin registers `codex`; the bundled Anthropic plugin provides the `claude-cli` CLI backend.

- `fallback`: `"pi"` or `"none"`. In `id: "auto"`, omitted fallback defaults to `"pi"` so old configs can keep using PI when no plugin harness claims a run. In explicit plugin runtime mode, such as `id: "codex"`, omitted fallback defaults to `"none"` so a missing harness fails instead of silently using PI. Runtime overrides do not inherit fallback from a broader scope; set `fallback: "pi"` alongside the explicit runtime when you intentionally want that compatibility fallback. Selected plugin harness failures always surface directly.

- Environment overrides: `OPENCLAW_AGENT_RUNTIME=<id|auto|pi>` overrides `id`; `OPENCLAW_AGENT_HARNESS_FALLBACK=pi|none` overrides fallback for that process.

- For Codex-only deployments, set `model: "openai/gpt-5.5"` and `agentRuntime.id: "codex"`. You may also set `agentRuntime.fallback: "none"` explicitly for readability; it is the default for explicit plugin runtimes.

- `id: "auto"` lets registered plugin harnesses claim supported turns and uses PI when no harness matches. An explicit plugin runtime such as `id: "codex"` requires that harness and fails closed if it is unavailable or fails.

- Environment override: `OPENCLAW_AGENT_RUNTIME=<id|auto|pi>` overrides `id` for that process.

- For Codex-only deployments, set `model: "openai/gpt-5.5"` and `agentRuntime.id: "codex"`.

- For Claude CLI deployments, prefer `model: "anthropic/claude-opus-4-7"` plus `agentRuntime.id: "claude-cli"`. Legacy `claude-cli/claude-opus-4-7` model refs still work for compatibility, but new config should keep provider/model selection canonical and put the execution backend in `agentRuntime.id`.

- Older runtime-policy keys are rewritten to `agentRuntime` by `openclaw doctor --fix`.

- Harness choice is pinned per session id after the first embedded run. Config/env changes affect new or reset sessions, not an existing transcript. Legacy sessions with transcript history but no recorded pin are treated as PI-pinned. `/status` reports the effective runtime, for example `Runtime: OpenClaw Pi Default` or `Runtime: OpenAI Codex`.

thinkingDefault: "high", // per-agent thinking level override

reasoningDefault: "on", // per-agent reasoning visibility override

fastModeDefault: false, // per-agent fast mode override

agentRuntime: { id: "auto", fallback: "pi" },

agentRuntime: { id: "auto" },

params: { cacheRetention: "none" }, // overrides matching defaults.models params by key

tts: {

providers: {