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 agentmods add skills/ax-llm/ax/ax-cpp-gennpx skills add ax-llm/ax --skill ax-cpp-gengit clone --depth 1 https://github.com/ax-llm/axWhat 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 | $0.00048 | $0.00753 |
| Opus 5 | $0.00024 | $0.00377 |
| Sonnet 5 | $0.00010 | $0.00151 |
| Haiku 4.5 | $0.00005 | $0.00075 |
Grade A, and why
ax-cpp-gen 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 — 60 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AxGen Structured Generation For C++
This skill helps an agent write C++ code with the generated Ax package axllm. Use the generated package API, examples, and manifests; do not import TypeScript-only APIs unless you are editing the TypeScript package.
When To Use
- Build a structured generation program from a signature.
- Attach typed tools or MCP-derived tools to a generation call.
- Generate multiple validated structured samples and select a winner with a native callback.
- Use package examples for no-key scripted clients and provider-api calls.
Package Facts
- Language: C++.
- Package:
axllm. - 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
auto program = axllm::ax("question:string -> answer:string");
auto out = program.forward(llm, { {"question", "What is Ax?"} });
Provider Forward Options
AxGen merges constructor and per-call forward options before invoking the provider. Provider-facing keys such as promptCacheKey, sessionId, and contextCache therefore reach the chat request without being copied into program inputs. Per-call values override constructor defaults.
structuredOutputMode / structured_output_mode accepts auto, native, function, or json_object. Auto follows the selected profile/model ordering, with the provider-neutral singleton string/code JSON-object optimization. Explicit modes must be advertised and fail before transport otherwise. JSON-object mode retains exact-shape prompting, strict parsing, and one bounded correction retry without a synthetic __axOutput tool.
Multi-Sampling
- Set
sampleCount/sample_countto request N provider candidates. Core parses and validates every candidate, preserving each provider result index. - Without a result picker, AxGen returns candidate 0. A result picker receives all
{ index, sample }structured candidates and returns the winning list index; Core rejects an index outside0..N-1. - Native callback surface:
set_sample_count/set_result_picker. - OpenAI-compatible Chat and Gemini map multi-sampling to
nandcandidateCount. Anthropic rejectsn > 1explicitly.
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 b3e7ec1abec5
- 2d ago First seen · 60 lines · 48 tokens per session scan A 2b1345eb7884
ax-cpp-gen is a skill published in the GitHub repository ax-llm/ax (2,890 stars, last pushed yesterday), licensed Apache-2.0. It adds 48 tokens to every session and 753 once invoked, about $0.0002 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 2026-08-30.
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