forecasting

forecasting is a skill for Claude Code, Codex from ericrisco/rsc-harness. It costs 80 tokens per session (2,751 once invoked), scanned A, original, MIT.

A guide to projecting future sales, demand, revenue, signups, or traffic from historical data. It includes uncertainty ranges and tests whether the forecast is better than simply repeating the last period.

In plain words
What is it for?
It helps choose a forecasting method, test it on past data, compare it with a simple baseline, and produce a reproducible forecast with an error range.
Why use it?
It reduces the risk of presenting an unsupported single-number guess as a forecast.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit It helps choose a forecasting method, test it on past data, compare it with a simple baseline, and produce a reproducible forecast with an error range.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/ericrisco/rsc-harness/forecasting
Install

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.

Any agent
npx skills add ericrisco/rsc-harness --skill forecasting
Clone the repo
git clone --depth 1 https://github.com/ericrisco/rsc-harness

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for forecasting

README.md
[![agentmods](https://agentmods.dev/badge/skills/ericrisco/rsc-harness/forecasting/github.svg)](https://agentmods.dev/skills/ericrisco/rsc-harness/forecasting)
Your own site
<a href="https://agentmods.dev/skills/ericrisco/rsc-harness/forecasting"><img src="https://agentmods.dev/badge/skills/ericrisco/rsc-harness/forecasting/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.

agentmods 80×15 button for forecasting

Your own site · 80×15
<a href="https://agentmods.dev/skills/ericrisco/rsc-harness/forecasting"><img src="https://agentmods.dev/badge/skills/ericrisco/rsc-harness/forecasting.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 80 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,751 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Excessive Agency · line 131
    Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.
    Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00080 $0.02751
Opus 5 $0.00040 $0.01375
Sonnet 5 $0.00016 $0.00550
Haiku 4.5 $0.00008 $0.00275

Measured 8d ago against content hash 9feab604d0eb, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

forecasting 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 8d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/verify.sh), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

skills/forecasting/SKILL.md · 140 lines

How it starts

The opening of the file, as written. The whole thing — 140 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Forecasting

A forecast that cannot beat "repeat last period" is noise. Baseline first, fancy second. The naive forecast is free, instant, and the bar every model must clear — if your AutoARIMA loses to last-quarter-repeated, ship the repeat and say so.

You are not done when a model produces a number. You are done when you can defend the number: which method, why that method for this data, how it scored against the naive baseline in a backtest, and the interval around the point. A point estimate with no error band is a guess wearing a lab coat.

The deliverable contract

Every forecast you ship is a reproducible artifact, not a number pasted in chat:

  1. A script that reads the history and regenerates the forecast (no manual steps).
  2. A CSV/Parquet with columns ds, forecast, lo, hi — timestamp, point, interval bounds.
  3. A one-paragraph accuracy readout: WAPE + bias from a rolling-origin backtest, and MASE vs the naive baseline (MASE < 1.0 = you beat naive; ≥ 1.0 = ship the naive forecast instead).

If you cannot produce all three, you have not forecast — you have guessed. scripts/verify.sh checks the artifact has these columns, the right row count, and an accuracy line.

The loop

Run these in order. Skipping step 3 is the most common failure.

  1. Frame it. Pin down the horizon h (how many periods forward), the granularity (daily / weekly / monthly), and exactly what is being predicted (units? revenue? per-SKU or aggregate?). Forecast at the level you will act on — if you reorder per SKU, forecast per SKU, then sanity-check against the aggregate.
  2. Establish the series. Regular timestamps, one row per period, gaps filled explicitly (a missing month is not zero unless it truly is). Flag promotions, stockouts, and outliers — they distort the signal. If the input is dirty (dupes, missing rows, mixed units), stop and hand off to data-cleaning before modeling. Garbage history, garbage forecast.
  3. Build the naive + seasonal-naive baseline. This is the bar. Naive = repeat last value. Seasonal-naive = repeat the value from one season ago (e.g. last December for this December). Compute its backtest error now — every fancier method must beat it or lose.
  4. Pick the method by data shape (table below). Do not reach for ARIMA on instinct.
  5. Backtest with rolling-origin cross-validation. Never a single holdout. Compute WAPE + bias + MASE vs the naive baseline across multiple cutoffs.
  6. Report. Point + interval, the one-line method rationale, the accuracy readout. Then hand off downstream (inventory, financial-model).

Read the full file on GitHub · 140 lines

Files

What ships with it

5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

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.

  1. 8d ago First seen · 140 lines · 80 tokens per session scan A 9feab604d0eb

Subscribe to this mod's changes

forecasting is a skill published in the GitHub repository ericrisco/rsc-harness (82 stars, last pushed yesterday), licensed MIT. It adds 80 tokens to every session and 2,751 once invoked, about $0.0004 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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