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Code Mode

Code mode is an experimental, opt-in OpenClaw agent-runtime feature. When enabled, the model no longer sees every enabled tool schema. Instead, it sees exec, wait, and any direct-only tool whose structured result cannot cross the JSON-only guest bridge. The model writes a small JavaScript or TypeScript program that searches, describes, and calls the hidden tool catalog.

This page documents OpenClaw Code Mode, not Codex Code Mode. The two features share a name and the same control-tool names (exec, wait), but they are separate implementations:

  • Codex Code Mode runs inside the Codex coding harness. Its exec tool is a freeform-grammar tool: the model writes raw JavaScript source (optionally prefixed by a // @exec: {...} pragma line for execution options), executed in Codex's in-process V8 Code Mode runtime.
  • OpenClaw Code Mode runs in the generic OpenClaw agent runtime and is enabled through global, agent, or model activation settings. Its exec tool takes a JSON { code, language } payload, executed in a QuickJS-WASI worker.

Both are JavaScript execution surfaces, not shell-command surfaces. Treat them as independent, differently-implemented features that happen to expose identically-named exec/wait tools.

In OpenClaw Code Mode, command is a JavaScript or TypeScript alias for code, not a shell command. For shell or file operations, call the appropriate async tool global from guest JavaScript. Recognizable shell commands are rejected before guest execution with actionable invalid_input guidance.

Source validation, TypeScript compilation, and guest execution run in a bounded pool of worker threads that scales with available CPU cores. Workers stay warm between calls. Each cell gets an isolated QuickJS VM. Fast host exchanges retain that VM within the same call rather than snapshotting every await. Tool permissions, approvals, and session ownership remain with the Gateway. Queued work shares the execution deadline, and cancellation stops an active worker before the call settles.

This page is an index. Code Mode is documented on eight pages, one per reader job. Open the page that matches your task.

Page Read it when
Code Mode quickstart You want to turn Code Mode on, override one model, and recover from tool errors.
Code Mode configuration You need the configuration fields, the preferred-model list, and activation order.

What it does

  • The model-visible tool list becomes exec, wait, plus any direct-only tool such as computer or the native-vision view_image loader whose image result cannot survive the guest bridge.
  • exec evaluates model-generated JavaScript or TypeScript in an isolated QuickJS-WASI worker thread.
  • Every catalog-eligible enabled non-MCP tool (OpenClaw core, plugin, client) is hidden as a standalone model tool and exposed inside the guest program as an async global function. MCP stays under the MCP namespace.
  • The exec description carries a bounded quick index of final callable names, compact input hints, and compact declared output hints when a trusted tool provides an output schema. It omits descriptions, full schemas, MCP entries, and overflow entries. Callable catalog.search(...) results are the fallback. Input hints retain integer and numeric bounds as comments, such as offset?: number /* integer, >= 1 */. Other validation details remain in the full schema available through describe(). These hints do not change tool validation or output contracts.
  • Guest code calls globals directly or searches the hidden catalog for callable handles. A handle exposes bounded metadata and describe(), but never the exact internal catalog id. Calls use the same execution path as normal agent turns (policy, approvals, hooks, telemetry all still apply).
  • MCP tools are grouped under the MCP namespace. In Code Mode this is the only supported way to call them.
  • wait resumes a suspended Code Mode run when nested tool calls are still pending.

Call wait only when the outer Code Mode result has status: "waiting", using its top-level runId. A completed cell can return a background shell operation with its own sessionId inside value. Use the enabled process-control tool inside a new exec to poll that operation. Its sessionId is not a Code Mode run ID.

Code mode changes the model-facing orchestration surface only. It does not replace tools, plugin tools, MCP tools, auth, approval policy, channel behavior, or model selection.

Why use it

  • Smaller prompt surface: providers get two control tools, a bounded native-tool index, and only the few required direct tools instead of dozens or hundreds of full tool schemas.
  • Better orchestration: the model can use loops, joins, small transforms, conditional logic, and parallel nested tool calls inside one code cell.
  • Fewer model round trips: a declared output contract lets the model call and transform a tool result in one exec. Unknown outputs remain raw-first.
  • Provider neutral: works for OpenClaw, plugin, MCP, and client tools without depending on provider-native code execution.
  • Fails closed: if Code Mode is enabled but the QuickJS-WASI runtime is unavailable, the run fails instead of silently falling back to broad direct tool exposure.

Most useful for agents with a large enabled tool catalog, or workflows where the model needs to search, combine, and call several tools before answering.

Keep direct tool exposure for a small catalog or a model that does not reliably write short programs. Use Tool Search when you want a compact catalog but prefer structured search/describe/call controls instead of the QuickJS-WASI guest.

Technical tour

These pages cover the runtime contract and implementation details, for maintainers, plugin authors debugging tool exposure, and operators validating high-risk deployments.

Page Read it when
Code Mode tool surface You need the exec and wait contracts, the hidden catalog, and collisions.
Code Mode guest API You are writing guest code and need its globals, handles, and MCP namespaces.
Code Mode output You need declared output contracts or the guest output API.
Code Mode internals You need scope, terms, nested execution, snapshots, or the security boundary.
Code Mode troubleshooting You need error codes, telemetry fields, or the debug environment variables.
Code Mode maintainer notes You are changing Code Mode source, validating it, or writing E2E coverage.

Where each section moved

Every section heading from the previous single-page version keeps its anchor here, so an existing link such as /tools/code-mode#guest-runtime-api still resolves. Each entry points at the page that now holds the content.

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