This skill helps an LLM generate correct AxAgent RLM/runtime code using @ax-llm/ax. Use when the user asks about RLM code execution, AxJSRuntime, contextFields, contextPolicy, liveRuntimeState, promptLevel, stage prompt controls, executorModelPolicy, maxRuntimeChars, agent.test(...), llmQuery(...), recursionOptions, or long-running agent runtime behavior.
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Use this skill for code-runtime agents and llmQuery(...) semantic-helper behavior. For ordinary agent setup, child agents, tool namespaces, clarification, and bubbleErrors, use ax-agent. For callbacks and logs, use ax-agent-observability. For memories and skill loading, use ax-agent-memory-skills.
agent(...), not new AxAgent(...).console.log(...) step per non-final actor turn.autoUpgrade (ON by default) for oversized inputs you did not declare in contextFields: any input value over ~8k serialized chars is kept runtime-only automatically, with a 1,200-char prompt preview plus a contextMetadata line, while the full value stays live in the runtime as inputs.<field>. Declare a field in contextFields only when you want a specific inline policy (promptMaxChars / keepInPromptChars) or need a large required non-string field kept out of the prompt (those are left inline by auto-upgrade).contextPolicy: { preset: 'checkpointed', budget: 'balanced' } for most RLM tasks.contextPolicy: { preset: 'adaptive', budget: 'balanced' } when older successful turns should collapse sooner while live runtime state stays visible.contextMap for recurring long-context corpora when the distiller should start future runs with a small persisted orientation cache.promptLevel: 'default' for normal use.promptLevel: 'detailed' when you want extra anti-pattern examples and tighter teaching scaffolding in the actor prompt.executorModelPolicy when the actor may need to upgrade after repeated error turns or discovery in specific namespaces without also upgrading the responder.functions: [...] when the task needs specialist agents with their own tools/runtime.llmQuery(...) only for focused semantic questions over narrowed context; it does not spawn a tool-using child AxAgent.maxSubAgentCalls only when you need an explicit cap on llmQuery(...) sub-query usage.AxAgent is a three-stage pipeline. Each forward() call walks the stages in order:
distiller (RLM actor) -> executor (RLM actor) -> responder (synthesizer)contextFields stay runtime-only when present. It distils relevant evidence by writing runtime-language code in a multi-turn loop, then calls the runtime-exposed final(request, evidence) primitive. The request becomes the executor's inputs.executorRequest; it must be self-contained and restate the concrete action, target, and constraints, not vague wording like "do it". The distiller should expand the original user task with facts found in context, including follow-ups like "yes, do it". When no contextFields are configured, it still performs request normalization over the original inputs with contextFields: []. The distiller has no tools and is not a capability gate.inputs.executorRequest, a compact distilledContextSummary prompt field, and the real evidence live as inputs.distilledContext from the distiller's final(request, evidence) payload. Declared or auto-promoted context fields stay runtime-readable as inputs.<field> when contextMetadata lists them, but their raw contents are not pasted into the executor prompt. The executor owns tool use, decides whether to call its available functions or finish directly from distilled evidence, and reports actual tool results or failures.With directResponse: 'auto' (the default), the distiller can end the run with the respond(task, evidence) primitive when the task needs no user-provided functions — the executor stage is skipped entirely (zero executor model calls) and the responder synthesizes straight from the distiller's evidence. Unlike final, whose evidence stays live in the shared session by reference, respond's evidence crosses into the responder prompt (budgeted by maxEvidenceChars), and the distiller's runtime variables are exported as the cross-run state exactly as the executor's would have been.
functions, no child agents) run respond-only: final is not offered to the distiller and every run is distiller → responder.respond alongside final under a conservative covenant: only for tasks answered purely by reading/synthesizing provided context, never when a listed function/module domain covers the need, never for current/live/fresh-state asks (context may be stale — tools are the source of truth for "now"), never for side effects. Landing-gate eval (both pinned models, 3 repeats): 0 false skips on tool-required tasks including a stale-context trap, 100% skip recall on pure context Q&A.directResponse: 'off' removes the primitive from the prompt and the runtime, and the pipeline rejects a respond payload outright.Treat both actor stages as long-running code runtime sessions that the actor steers over multiple turns, not as fresh script generators on every turn. AxJSRuntime is the default; custom runtimes set language so the actor code field becomes <language>Code such as pythonCode while JavaScript keeps the legacy javascriptCode.
actionLog, liveRuntimeState, and checkpoint summaries only control what the actor can see again in the prompt.Use these rules when generating actor JavaScript for RLM in AxJSRuntime stdout mode. For custom runtimes, follow the runtime's getUsageInstructions(), primitive overrides, and callable formatter instead.
console.log(...) it, and stop immediately after that console.log(...).Action Log only as evidence for what happened.Live Runtime State, treat it as the canonical view of current variables.Action Log; inspect them and fix the code on the next turn.console.log(...).await final(outputGenerationTask, context) or await askClarification(...) without console.log(...).console.log(...) with await final(...) or await askClarification(...) in the same actor turn.await final(...) and await askClarification(...) end the current turn immediately; code after them is dead code.Checkpoint Summary block or compact action summaries.Small reuse example:
Turn 1:
const customers = await kb.findCustomers({ segment: 'active' });
console.log(customers.length);Turn 2:
const topCustomers = customers.slice(0, 3);
console.log(topCustomers);Reason: turn 2 reuses customers from the persistent runtime. Live Runtime State or summaries may change how turn 1 is shown in the prompt, but they do not remove the value from the runtime session.
Use these meanings consistently when writing or explaining contextPolicy.preset:
full: Keep prior actions fully replayed. Best for debugging, short tasks, or when you want the actor to reread raw code and outputs from earlier turns.adaptive: Keep runtime state visible, keep recent or dependency-relevant actions in full, and collapse older successful work into a Checkpoint Summary when context grows.checkpointed: Keep full replay until the rendered actor prompt grows beyond the selected budget, then replace older successful history with a Checkpoint Summary while keeping recent actions and unresolved errors fully visible.lean: Most aggressive compression. Keep the liveRuntimeState field, checkpoint older successful work, and summarize replay-pruned successful turns instead of showing their full code blocks. Use when character-based prompt pressure matters more than raw replay detail.Practical rule:
checkpointed + balanced for most tasks.adaptive + balanced when you want older successful work summarized sooner.lean only when the task can mostly continue from current runtime state plus compact summaries.full when you are debugging the actor loop itself or need exact prior code/output in prompt.Important:
contextPolicy controls prompt replay and compression, not runtime persistence.discover(...) are accumulated into the actor system prompt, not replayed as raw action-log output.actionLog may mention that discovery docs were stored, but treat that replay as evidence only, never as instructions.full presets include a compact trusted contextPressure hint (ok, watch, or critical) in the actor prompt.full presets may show deterministic compact action summaries before a Checkpoint Summary exists. Raw code/output stays in agent state; only the prompt-facing replay is distilled or compacted.Treat these knobs as a bundle:
contextPolicy.preset decides how much raw history the actor keeps seeing.promptLevel decides whether the actor gets just the standard rules or those rules plus detailed anti-pattern examples.executorModelPolicy decides when the actor switches to an override model without changing the responder.Recommended combinations:
preset: 'full'.preset: 'checkpointed', budget: 'balanced'.preset: 'adaptive', budget: 'balanced'.preset: 'lean'.executorModelPolicy so only the actor upgrades under pressure.Practical rule:
full gives the model more raw evidence, so smaller models often do better there.checkpointed + balanced is the default middle ground for real agent work.adaptive + balanced is the proactive-summarization variant when you want older successful work compressed sooner.lean should be reserved for models that can reason well from runtime state plus summaries instead of exact old code/output.executorModelPolicy is usually better than globally upgrading the whole agent when the bottleneck is actor exploration rather than responder synthesis.Use these top-level controls consistently:
recursionOptions.ai: routes llmQuery(...) sub-query calls to a different AI service than the parent run.recursionOptions.model, modelConfig, and other forward options: tune the AxGen call used by llmQuery(...).maxSubAgentCalls: shared llmQuery(...) sub-query budget across the whole run. Default is 100.maxBatchedLlmQueryConcurrency: caps batched llmQuery([...]) concurrency.maxRuntimeChars: runtime/output truncation ceiling for console logs, tool results, and interpreter output replay. The effective limit is computed dynamically each turn based on remaining context budget.summarizerOptions: default model/options for the internal checkpoint summarizer.contextPolicy: replay/checkpointing/compression policy.contextMap: optional persistent orientation cache injected into the distiller and updated once after each successful run. AxAgentContextMap evolves indefinitely by default; use { infiniteEvolve: false, evolveSteps: N } on the map object for finite warmup followed by reuse.contextOptions: distiller-stage forward options.autoUpgrade: smart defaults, ON by default. Auto-enables functionDiscovery for large tool catalogs and keeps oversized undeclared input values runtime-only with a truncated prompt preview. Set false to opt out, or tune per side: { functionDiscovery?: boolean | { aboveFunctionDocChars }, contextFields?: boolean | { promoteAboveChars, previewChars } }. Explicit functionDiscovery and declared contextFields always win.executorOptions: executor-stage forward options such as description, model, modelConfig, thinkingTokenBudget, and showThoughts.executorModelPolicy: executor-only model override rules based on consecutive error turns or discovery fetches from listed namespaces.responderOptions: responder-stage forward options.judgeOptions: built-in judge options for agent.optimize(...); for tuning workflows use ax-agent-optimize.Canonical shape:
const researchAgent = agent('query:string -> answer:string', {
contextFields: ['query'],
runtime,
recursionOptions: {
model: 'gpt-5.4-mini',
},
maxRuntimeChars: 3000,
summarizerOptions: {
model: 'gpt-5.4-mini',
modelConfig: { temperature: 0.1, maxTokens: 180 },
},
contextPolicy: {
preset: 'checkpointed',
budget: 'balanced',
},
contextOptions: {
model: 'gpt-5.4-mini',
maxTurns: 3,
},
executorOptions: {
description: 'Use tools first and keep JS steps small.',
model: 'gpt-5.4-mini',
},
executorModelPolicy: [
{
model: 'gpt-5.4',
aboveErrorTurns: 2,
namespaces: ['db', 'kb'],
},
],
responderOptions: {
model: 'gpt-5.4-mini',
},
});Semantics:
maxRuntimeChars sets the truncation ceiling and is separate from contextPolicy.budget.summarizerOptions tunes only the internal checkpoint summarizer. It does not change actor or responder model selection.executorModelPolicy only switches the actor model. It does not change responderOptions.model.llmQuery(...) uses recursionOptions.ai when set, otherwise it falls back to the parent .forward(ai, ...) service.recursionOptions configures the AxGen semantic sub-query used by llmQuery(...); it does not create a child AxAgent and cannot give the sub-query tools.executorModelPolicy entries are ordered from weaker to stronger. If multiple rules match, the last matching entry wins.namespaces, any successful discover(...) function-definition fetch from one of those namespaces marks the rule as matched starting on the next actor turn.recursionOptions unless the user needs different model/options for llmQuery(...).Runtime output truncation is budget-proportional and type-aware:
maxRuntimeChars ceiling.targetPromptChars, the limit decays linearly down to 15% of the ceiling, hard-floored at 400 chars.... [N hidden items].[Object] or [Array(N)].JSON.stringify passthrough.Users do not need to configure this behavior. maxRuntimeChars sets the upper bound; the dynamic system only reduces it.
The pipeline has three peer stage-config bags: contextOptions (distiller), executorOptions (executor), and responderOptions (responder). Each accepts the same shape: description, model, modelConfig, excludeFields, plus other forward options.
Key fields:
contextOptions.description: append extra distiller-specific instructions.executorOptions.description: append extra executor-specific instructions; this is the typical place for tool-use guidance.responderOptions.description: append extra responder-specific instructions.contextOptions.model / executorOptions.model / responderOptions.model: split model choice across stages.contextOptions.ai / executorOptions.ai / responderOptions.ai: override the AI service for a specific stage.executorModelPolicy: auto-switch only the executor when the run is on a consecutive error streak or discovery fetches land in specific namespaces.Good split-model pattern:
const researchAgent = agent('query:string -> answer:string', {
contextFields: ['query'],
runtime,
contextPolicy: { preset: 'checkpointed', budget: 'balanced' },
executorOptions: {
model: 'gpt-5.4',
},
responderOptions: {
model: 'gpt-5.4-mini',
},
});Model guidance:
executorModelPolicy over globally upgrading the whole agent when the actor only needs help after context grows or the run starts thrashing.Prompt/cache shape:
contextMetadata, contextMap, memories, executorRequest, distilledContextSummary, discoveredToolDocs, loadedSkills, and summarizedActorLog.guidanceLog, actionLog, liveRuntimeState, and contextPressure.final(...) or askClarification(...).Invalid actor turn:
await discover(['kb.findSnippets']);
const snippets = await kb.findSnippets({ topic: 'severity' });
await final("Summarize severity findings", { snippets });Reason: this mixes observation and follow-up work in one turn. discover(...) returns void; read the next prompt's "Discovered Tool Docs" section before calling the function.
Default new AxJSRuntime() is hardened: no network, no filesystem, no child process, dynamic import() blocked, intrinsics frozen, ShadowRealm locked to undefined, worker IPC locked in browser/Deno/Bun, Bun workers use smol: true, and on Node 20+ the OS Permission Model auto-engages where available.
Threat model: this is defense-in-depth for LLM-authored code, not a container or VM boundary. Host callbacks and granted runtime permissions remain the authority boundary; keep durable secrets and privileged effects in host-side functions.
Permission enum (AxJSRuntimePermission):
NETWORK, STORAGE, CODE_LOADING, COMMUNICATION, TIMING, WORKERS, FILESYSTEM, CHILD_PROCESS.
Options quick reference:
permissions?: readonly AxJSRuntimePermission[]: default []; opt in capabilities.blockDynamicImport?: boolean: default true.allowedModules?: readonly string[]: default []; narrow dynamic-import allowlist gate. Allowlisted specifiers are attempted, but full Node module namespace passthrough depends on Node vm semantics.freezeIntrinsics?: boolean: default true.blockShadowRealm?: boolean: default true.lockWorkerIPC?: boolean: default true.preventGlobalThisExtensions?: boolean: default false; opt-in and breaks top-level persistence.useNodePermissionModel?: boolean | 'auto': default 'auto'.nodePermissionAllowlist?: { fsRead?; fsWrite?; childProcess?; addons?; wasi? }.resourceLimits?: { maxOldGenerationSizeMb?; maxYoungGenerationSizeMb?; codeRangeSizeMb?; stackSizeMb? }.allowDenoRemoteImport?: boolean: default false.allowUnsafeNodeHostAccess?: boolean: default false.Recipes:
new AxJSRuntime();
new AxJSRuntime({ permissions: [AxJSRuntimePermission.NETWORK] });
new AxJSRuntime({
permissions: [AxJSRuntimePermission.FILESYSTEM],
allowedModules: ['node:fs', 'node:fs/promises', 'node:path'],
useNodePermissionModel: 'auto',
nodePermissionAllowlist: {
fsRead: ['/app/data'],
fsWrite: ['/app/data'],
},
});Rules for the LLM author:
new AxJSRuntime() with no options unless the user asked for a specific capability.fetch, add permissions: [AxJSRuntimePermission.NETWORK].permissions: [AxJSRuntimePermission.FILESYSTEM], scope with nodePermissionAllowlist when the user names a directory, and treat allowedModules as an import allowlist gate rather than a portability guarantee.freezeIntrinsics, blockShadowRealm, or lockWorkerIPC unless the user explicitly asks.allowUnsafeNodeHostAccess: true as a red flag; only use it when the user is authoring trusted code in their own process.preventGlobalThisExtensions: true breaks top-level var/let/const persistence across turns; never set it for stdout-mode RLM where persistence is load-bearing.blockDynamicImport is a no-op; the defense is the worker permission sandbox. Pass allowDenoRemoteImport: true only if remote module loading is genuinely required.Implement AxCodeRuntime when the actor should write a language other than JavaScript.
language to the model-facing language name. JavaScript aliases (JavaScript, js, ecmascript) keep javascriptCode; other values derive lower-camel code fields such as pythonCode or cSharpCode.createSession(globals, options). AxAgent passes inputs, llmQuery, final, askClarification, progress callbacks, memory/discovery primitives, and namespaced tools as host globals; the runtime decides how those globals appear in the target language.getUsageInstructions().getPrimitiveOverrides() to describe language-native calls for built-in primitives, and formatCallable() to describe language-native calls for tools and child agents.inspectGlobals() on sessions when contextPolicy should show live runtime state for non-JavaScript runtimes; otherwise AxAgent will not run JavaScript fallback inspection snippets.Use agent.test(code, contextFieldValues?, options?) when the user wants to validate runtime snippets against the actual AxAgent runtime environment without running the full actor/responder loop. With AxJSRuntime, those snippets are JavaScript.
import { AxJSRuntime, agent, f, fn } from '@ax-llm/ax';
const runtime = new AxJSRuntime();
const tools = [
fn('sum')
.description('Return the sum of the provided numeric values')
.namespace('math')
.arg('values', f.number('Value to add').array())
.returns(f.number('Sum of all values'))
.handler(async ({ values }) =>
values.reduce((total, value) => total + value, 0)
)
.build(),
];
const toolHarness = agent('query:string -> answer:string', {
contextFields: [],
runtime,
functions: tools,
contextPolicy: { preset: 'checkpointed', budget: 'balanced' },
});
const toolOutput = await toolHarness.test(
'console.log(await math.sum({ values: [3, 5, 8] }))'
);
console.log(toolOutput);Rules:
test(...) creates a fresh runtime session per call.inputs plus non-colliding top-level aliases for configured contextFields.contextFields, or test the executor stage directly, so namespaced functions, child agents, and llmQuery(...) are in scope.AxJSRuntime, do not rely on calling inspectRuntime() from inside test(...) snippets yet; prefer checking runtime globals directly inside the snippet.final(...) or askClarification(...) inside test(...) snippets.contextFields values to test(...); it is not a general way to inject arbitrary non-context inputs.llmQuery(...), provide an AI service through the agent config or options.ai.llmQuery(...) RulesAvailable forms:
await llmQuery(query, context?)await llmQuery({ query, context? })await llmQuery([{ query, context }, ...])Rules:
llmQuery(...) forwards only the explicit context argument.llmQuery(...); include any needed facts in context.llmQuery(...) is a direct semantic helper backed by an AxGen sub-query. It does not create a child AxAgent, does not run an actor runtime session, and does not have access to tools or discovery.llmQuery([...]) only for independent semantic questions. Use serial calls when later work depends on earlier results.llmQuery(...).maxSubAgentCalls is a shared budget for llmQuery(...) sub-queries across the top-level run.llmQuery(...) may return [ERROR] ... on non-abort failures.llmQuery([...]) returns per-item [ERROR] ....[ERROR], inspect or branch on it instead of assuming success.Minimal example:
const summary = await llmQuery('Summarize this incident', inputs.context);
if (summary.startsWith('[ERROR]')) {
console.log(summary);
} else {
console.log(summary);
}Parallel semantic review example:
const narrowedIncidents = incidents.map((incident) => ({
id: incident.id,
timeline: incident.timeline,
notes: incident.notes.slice(0, 1200),
}));
const [severityReview, followupReview] = await llmQuery([
{
query:
'Use discovery and available tools to review severity policy alignment. Return compact findings.',
context: {
incidents: narrowedIncidents,
rubric: 'severity-policy',
},
},
{
query:
'Use discovery and available tools to review postmortem and follow-up obligations. Return compact findings.',
context: {
incidents: narrowedIncidents,
rubric: 'postmortem-followup',
},
},
]);
const merged = await llmQuery(
'Merge these delegated reviews into one manager-ready summary with next steps.',
{
severityReview,
followupReview,
audience: inputs.audience,
}
);Delegation decision guide:
llmQuery(...) with narrow context.agent(...) and pass it in functions: [...].llmQuery([...]).Context handling:
inputs.*.{ emails: filtered, rubric: 'classify-urgency' }.maxSubAgentCalls is shared across the run.Patterns:
llmQuery([...]) fans out per category -> JS or one more llmQuery(...) merges semantic results.llmQuery(...) calls where each depends on the prior result.await team.writer({ draft }).Fetch these for full working code:
llmQuery(...)Flagship real-world long-agents (also ported to Python, Go, Rust, Java, and C++ under src/examples/<lang>/long-agents/; run with npm run example -- <lang> <path>):
contextFields (Gemini)contextFields + typed warehouse tools the model queries instead of inliningconsole.log(...) with final(...).llmQuery(...) as spawning a tool-using child AxAgent.llmQuery(...) unless passed in context.[ERROR] ... results from llmQuery(...).AxJSRuntime permissions unless the user asked for the capability.If you maintain this skill, you can claim it as your own. Once claimed, you can manage eval scenarios, bundle related skills, attach documentation or rules, and ensure cross-agent compatibility.