When unset, compaction starts with the active session model. If summarization fails with a model-fallback-eligible provider error, OpenClaw retries that compaction attempt through the session's existing model fallback chain. The fallback choice is temporary and is not written back to session state. An explicit `agents.defaults.compaction.model` override remains exact and does not inherit the session fallback chain.

The memory-flush model override is exact and does not inherit the active session fallback chain. See [Memory](/concepts/memory) for details and config.

midTurnPrecheck: { enabled: false }, // optional tool-loop pressure check

postCompactionSections: ["Session Startup", "Red Lines"], // opt in to AGENTS.md section reinjection

model: "openrouter/anthropic/claude-sonnet-4-6", // optional compaction-only model override

truncateAfterCompaction: true, // rotate to a smaller successor JSONL after compaction

maxActiveTranscriptBytes: "20mb", // optional preflight local compaction trigger

notifyUser: true, // send brief notices when compaction starts and completes (default: false)

- `midTurnPrecheck`: optional tool-loop pressure check. When `enabled: true`, OpenClaw checks context pressure after tool results are appended and before the next model call. If the context no longer fits, it aborts the current attempt before submitting the prompt and reuses the existing precheck recovery path to truncate tool results or compact and retry. Works with both `default` and `safeguard` compaction modes. Default: disabled.

- `postCompactionSections`: optional AGENTS.md H2/H3 section names to re-inject after compaction. Reinjection is disabled when unset or set to `[]`. Explicitly setting `["Session Startup", "Red Lines"]` enables that pair and preserves the legacy `Every Session`/`Safety` fallback. Enable this only when the extra context is worth the risk of duplicating project guidance already captured in the compaction summary.

- `model`: optional `provider/model-id` override for compaction summarization only. Use this when the main session should keep one model but compaction summaries should run on another; when unset, compaction uses the session's primary model.

- `maxActiveTranscriptBytes`: optional byte threshold (`number` or strings like `"20mb"`) that triggers normal local compaction before a run when the active JSONL grows past the threshold. Requires `truncateAfterCompaction` so successful compaction can rotate to a smaller successor transcript. Disabled when unset or `0`.

- `notifyUser`: when `true`, sends brief notices to the user when compaction starts and when it completes (for example, "Compacting context..." and "Compaction complete"). Disabled by default to keep compaction silent.

- `memoryFlush`: silent agentic turn before auto-compaction to store durable memories. Set `model` to an exact provider/model such as `ollama/qwen3:8b` when this housekeeping turn should stay on a local model; the override does not inherit the active session fallback chain. Skipped when workspace is read-only.

Outer run loop retry iteration boundaries for the embedded agent runtime to prevent infinite execution loops during failure recovery. Note that this setting currently only applies to the embedded agent runtime, not ACP or CLI runtimes.

- `thinkingDefault`: optional per-agent default thinking level (`off | minimal | low | medium | high | xhigh | adaptive | max`). Overrides `agents.defaults.thinkingDefault` for this agent when no per-message or session override is set. The selected provider/model profile controls which values are valid; for Google Gemini, `adaptive` keeps provider-owned dynamic thinking (`thinkingLevel` omitted on Gemini 3/3.1, `thinkingBudget: -1` on Gemini 2.5).

- `reasoningDefault`: optional per-agent default reasoning visibility (`on | off | stream`). Overrides `agents.defaults.reasoningDefault` for this agent when no per-message or session reasoning override is set.

- `fastModeDefault`: optional per-agent default for fast mode (`true | false`). Applies when no per-message or session fast-mode override is set.

- `models`: optional per-agent model catalog/runtime overrides keyed by full `provider/model` ids. Use `models["provider/model"].agentRuntime` for per-agent runtime exceptions.

- `runtime`: optional per-agent runtime descriptor. Use `type: "acp"` with `runtime.acp` defaults (`agent`, `backend`, `mode`, `cwd`) when the agent should default to ACP harness sessions.

- `identity.avatar`: workspace-relative path, `http(s)` URL, or `data:` URI.

and keeps OpenClaw runtime's recent-tail cut point. Without an explicit keep budget,

manual compaction remains a hard checkpoint and rebuilt context starts from

the new summary.

- Set `agents.defaults.compaction.midTurnPrecheck.enabled: true` to run the

optional tool-loop precheck after new tool results and before the next model

call. This is a trigger only; summary generation still uses the configured

executionCwd: string;

sandboxPolicy: CodexSandboxPolicy | undefined;

releaseSharedClientLease: () => void;

export async function startCodexAttemptThread(params: {

environmentSelection: startupEnvironmentSelection,

executionCwd: startupExecutionCwd,

sandboxPolicy: startupSandboxPolicy,

};

} catch (error) {

await releaseStartupSandboxEnvironment();