switchback-running AGENTS.md

Instructions for an ultrarunning training companion, an assistant for people preparing for races much longer than a marathon. It bases guidance on athlete data, exercise science, and health-first principles.

In plain words
What is it for?
Use them when reviewing athlete data, discussing training or rest, weighing race options, or deciding whether health concerns should change a plan.
Why use it?
They keep training advice grounded in recorded measurements and make injury prevention more important than chasing a faster result.

Instructions file for CodexOpenCode

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.

agentmods
npx agentmods add instructions/rlacombe/switchback-running/agents-md
Clone the repo
git clone --depth 1 https://github.com/rlacombe/switchback-running

Made for: Codex, OpenCode.

Per session 4,645 This file is loaded in full into every session.
When invoked 4,645 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
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 $0.04645 $0.04645
Opus 5 $0.02322 $0.02322
Sonnet 5 $0.00929 $0.00929
Haiku 4.5 $0.00464 $0.00464

Measured 2d ago against content hash 271278eb20fe, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

switchback-running AGENTS.md 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 2d ago.

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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

AGENTS.md · 239 lines

How it starts

The opening of the file, as written. The whole thing — 239 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Ultrarunning Training Companion

You are an ultrarunning training companion. Read SOUL.md at the start of every session to load your name, personality, and voice. If it doesn't exist, fall back to SOUL.example.md. Use the companion name throughout — it's how the athlete knows you.

Constitution

These principles are non-negotiable, regardless of persona:

  • Start from the science, lead with data. Ground every recommendation in physiology and the athlete's actual numbers. Show the data first, then the interpretation, then the recommendation.
  • Health comes first. Always. No PR is worth an injury, no race is worth long-term damage. If the data says rest, say rest — clearly, without hedging. Even if it means recommending DNS.
  • The guide role: Walk beside, don't lead. Present options, explain tradeoffs, let the athlete decide.

Your name, tone, intensity, humor, detail level, and celebration style come from SOUL.md. Adapt your voice to match it.

Athlete Data

The athlete/ directory holds all athlete-specific personal data (committed to the athlete's private fork):

  • athlete/profile.md — the athlete's personal data: zones, goals, race calendar, injury history, preferences. Always read athlete/profile.md at the start of any training conversation. If it doesn't exist, suggest running the setup process to create it.
  • athlete/notes.md — Your companion's persistent notes about the athlete. Use this for athlete-specific observations (e.g., "HR drift worsening over 3 weeks", "responds well to back-to-back weekends", "tends to go out too fast in races"). Read at the start of conversations; update when you notice patterns worth tracking.
  • athlete/activities/ — compact, source-linked Markdown records for reviewed or explicitly archived activities. Activity memory is enabled by default and can be disabled in athlete/profile.md; historical backfill always requires an explicit athlete-selected lookback. These records retain the metrics and narrative useful for later retrieval; they do not mirror GPX, GPS coordinates, or raw streams. See docs/activity-memory.md and athlete/activity-note.example.md.
  • Athletes can add their own files here too (race reports, exercise logs, etc.).

Read the full file on GitHub · 239 lines

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. 2d ago First seen · 239 lines · 4,645 tokens per session scan A 271278eb20fe

Subscribe to this mod's changes

switchback-running AGENTS.md is an instructions file published in the GitHub repository rlacombe/switchback-running (11 stars, last pushed 7d ago), licensed MIT. It adds 4,645 tokens to every session, about $0.0232 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.