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-java-signaturegit 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-java-signature)<a href="https://agentmods.dev/skills/ax-llm/ax/ax-java-signature"><img src="https://agentmods.dev/badge/skills/ax-llm/ax/ax-java-signature/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-java-signature"><img src="https://agentmods.dev/badge/skills/ax-llm/ax/ax-java-signature.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 | $0.00038 | $0.02252 |
| Opus 5.5 | $0.00015 | $0.00901 |
| Sonnet 5.5 | $0.00008 | $0.00450 |
| Haiku 4.5 | $0.00004 | $0.00225 |
Grade A, and why
ax-java-signature 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 today.
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 — 141 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Ax Signatures For Java
This skill helps an agent write Java code with the generated Ax package dev.axllm:ax. Use the generated package API, examples, and manifests; do not import TypeScript-only APIs unless you are editing the TypeScript package.
When To Use
- Declare input and output contracts with native generated-package APIs.
- Generate JSON-schema-compatible shapes for outputs, tools, prompts, and validation.
- Keep Standard Schema and TypeScript-only helper libraries out of generated-language code.
Package Facts
- Language: Java.
- Package:
dev.axllm:ax. - Package API docs:
API.mdandaxir-api.json. - Capability manifest:
axir-capabilities.json. - Runnable examples:
examples/. - Real network support: yes.
- Scripted no-key transport support: yes.
- Runtime profiles:
javascript-quickjs,python-pyodide.
Core Pattern
import dev.axllm.ax.*;
AxSignature sig = Ax.s("question:string -> answer:string");
var schema = sig.toJsonSchema("outputs", java.util.Map.of());
More Patterns
Simple string contract
Use the string form when field names and types are enough.
AxGen program = Ax.ax("questionText:string -> answerText:string");
Bounded class output
A class field constrains the model to a known label set.
AxGen router = Ax.ax(
"messageText:string -> routeClass:class \"support, sales, engineering\"");
Fluent constraints
Java exposes the native fluent builder for validation constraints and objects.
AxSignature signature = Ax.f().call()
.input("contactEmail", Ax.f().string("Contact email").email())
.output("partySize", Ax.f().number("Guests").min(1).max(12))
.output("bookingCode", Ax.f().string().regex("^[A-Z]{3}-\\d{4}$", "ABC-1234"))
.build();
JSON schema
Render the output contract for tools, validators, or external consumers.
var schema = signature.toJsonSchema("outputs", java.util.Map.of());
Reuse the signature
Pass one built signature into AxGen and call it like any other program.
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.
- today Changed 09e1b05e7be2
- 2d ago Changed 3a21e3a4c15e
- 3d ago Changed 40a0263c9af3
- 5d ago Changed · +6 lines f8a15ad7b865
- 7d ago Changed e254a689ea3b
- 9d ago Changed · +10 lines 8906d505ef8d
- 12d ago Changed 28f0bb61aba3
- 13d ago Changed · +10 lines b5cc9919633a
- 14d ago Changed 5ac241a3e4bd
- 20d ago First seen · 115 lines · 38 tokens per session scan A a69e802105e8
ax-java-signature is a skill published in the GitHub repository ax-llm/ax (2,968 stars, last pushed today), licensed Apache-2.0. It adds 38 tokens to every session and 2,252 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-08-30.
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