Ax is a TypeScript-first programming framework for building applications with large language models through typed generation, agents, workflows, and optimization tools. It is intended for developers who want one model for LLM programs across TypeScript, Python, Java, C++, Go, Rust, and other runtimes.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add ax-llm/ax --skill ax-agent-observabilitygit clone --depth 1 https://github.com/ax-llm/axWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/ax-llm/ax/ax-agent-observability)<a href="https://agentmods.dev/skills/ax-llm/ax/ax-agent-observability"><img src="https://agentmods.dev/badge/skills/ax-llm/ax/ax-agent-observability/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/ax-llm/ax/ax-agent-observability"><img src="https://agentmods.dev/badge/skills/ax-llm/ax/ax-agent-observability.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00095 | $0.03970 |
| Opus 5 | $0.00048 | $0.01985 |
| Sonnet 5 | $0.00019 | $0.00794 |
| Haiku 4.5 | $0.00010 | $0.00397 |
Grade A, and why
ax-agent-observability scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 409 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AxAgent Observability Rules (@ax-llm/ax)
Use this skill when an agent needs runtime visibility, progress reporting, tracing, usage accounting, or chat-log access. For ordinary agent setup use ax-agent. For RLM runtime policy use ax-agent-rlm. For memories and dynamic skill loading use ax-agent-memory-skills.
Choose The Smallest Hook
- Need a quick prompt/runtime trace during development -> start with
debug: true. - Need structured per-turn code, raw runtime result, formatted output, provider thoughts, or actor stage -> use
actorTurnCallback. - Need context-pressure and compaction telemetry -> use
onContextEvent. - Need real-time task progress emitted by actor code -> use
agentStatusCallback. - Need every runtime function call before execution -> use
onFunctionCall. - Need model prompts/responses after a run -> use
getChatLog(). - Need centralized chat/embed usage across APIs, users, agents, and services -> use
axGlobals.onUsageplususageContext. - Need token usage by actor/responder -> use
getUsage()andresetUsage(). - Need usage split by context and task stages -> use
getStagedUsage(). - Need Ax program traces -> use
getTraces(). - Do not add multiple hooks unless the user clearly needs each output stream.
Global Runtime Defaults
OpenTelemetry and debug defaults come from the shared Ax runtime surface:
import { axGlobals, axCreateDefaultColorLogger } from '@ax-llm/ax';
import { metrics, trace } from '@opentelemetry/api';
axGlobals.rateLimiter = async (next, info) => next();
axGlobals.tracer = trace.getTracer('agent-app');
axGlobals.meter = metrics.getMeter('agent-app');
axGlobals.debug = true;
axGlobals.logger = axCreateDefaultColorLogger();
axGlobals.onUsage = (event) => usageQueue.enqueue(event);
Each agent run snapshots these globals. A forward-scoped rateLimiter, tracer, or meter overrides agent defaults, child-generator defaults, service hooks, and globals for that invocation. Ax carries it through the distiller, executor, responder, repeated actor turns, citation repair, built-in llmQuery, context-map work, checkpoint/tombstone summaries, and other direct internal model calls without mutating child programs or leaking across concurrent runs.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- yesterday Changed 6ae03e86c1eb
- 5d ago First seen · 409 lines · 95 tokens per session scan A 2c76c420966e
ax-agent-observability is a skill published in the GitHub repository ax-llm/ax (2,893 stars, last pushed yesterday), licensed Apache-2.0. It adds 95 tokens to every session and 3,970 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
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output-dev-prompt-file
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develop-ai-functions-example
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