bruges

bruges is a skill for Claude Code, Codex from SteadfastAsArt/geoscience-skills. It costs 111 tokens per session (1,967 once invoked), scanned A, original, MIT.

A Python library of equations and calculations for seismic analysis and rock physics, the study of how rocks and fluids affect measurements.

In plain words
What is it for?
Use it to calculate AVO, how reflection changes with angle, model fluid substitution, create Ricker or Ormsby wavelets, and produce synthetic seismograms.
Why use it?
It avoids reimplementing standard formulas for wave reflection, rock properties, fluid changes, and seismic signals.

Skill for Claude CodeCodex

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

Good fit Use it to calculate AVO, how reflection changes with angle, model fluid substitution, create Ricker or Ormsby wavelets, and produce synthetic seismograms.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/steadfastasart/geoscience-skills/bruges
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 SteadfastAsArt/geoscience-skills --skill bruges
Clone the repo
git clone --depth 1 https://github.com/SteadfastAsArt/geoscience-skills

Made for: Claude Code, Codex.

Its marketplace also offers this one on its own, as the plugin bruges/plugin install bruges after adding the marketplace above.

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 bruges

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

Your own site · 80×15
<a href="https://agentmods.dev/skills/steadfastasart/geoscience-skills/bruges"><img src="https://agentmods.dev/badge/skills/steadfastasart/geoscience-skills/bruges.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 111 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,967 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.
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 $0.00111 $0.01967
Opus 5 $0.00056 $0.00983
Sonnet 5 $0.00022 $0.00393
Haiku 4.5 $0.00011 $0.00197

Measured 10d ago against content hash 93ebd82b41a0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

bruges 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 10d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/avo_analysis.py), 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.

bruges/SKILL.md · 190 lines

How it starts

The opening of the file, as written. The whole thing — 190 lines — stays where its author put it; the contents beside it link to each section on GitHub.

bruges - Geophysics Equations

Quick Reference

import bruges
import numpy as np

# AVO - Zoeppritz reflectivity
from bruges.reflection import zoeppritz
theta = np.arange(0, 45, 1)
Rpp = zoeppritz(vp1, vs1, rho1, vp2, vs2, rho2, theta)

# Wavelet - Ricker
from bruges.filters import ricker
t, w = ricker(duration=0.128, dt=0.001, f=25)

# Fluid substitution
from bruges.rockphysics import gassmann
vp_new, vs_new, rho_new = gassmann(vp, vs, rho, k_min, rho_min,
                                    k_fl1, rho_fl1, k_fl2, rho_fl2, phi)

Module Overview

Module Purpose
bruges.reflection Zoeppritz, Shuey, Aki-Richards AVO equations
bruges.rockphysics Gassmann, Gardner, Castagna, elastic moduli
bruges.filters Ricker, Ormsby wavelets, convolution

AVO Analysis

from bruges.reflection import zoeppritz, shuey, akirichards
theta = np.arange(0, 45, 1)  # degrees

Rpp = zoeppritz(vp1, vs1, rho1, vp2, vs2, rho2, theta)  # Exact
Rpp = shuey(vp1, vs1, rho1, vp2, vs2, rho2, theta)      # Fast (~30 deg)
Rpp, G = akirichards(vp1, vs1, rho1, vp2, vs2, rho2, theta, return_gradient=True)

Fluid Substitution

from bruges.rockphysics import gassmann

vp_new, vs_new, rho_new = gassmann(
    vp_sat, vs_sat, rho_sat,   # Original saturated rock
    k_min, rho_min,             # Mineral (quartz: 37 GPa, 2.65 g/cc)
    k_fl1, rho_fl1,             # Original fluid (brine: 2.5 GPa, 1.05 g/cc)
    k_fl2, rho_fl2,             # New fluid (oil: 0.9 GPa, 0.8 g/cc)
    phi                         # Porosity
)

Wavelets

from bruges.filters import ricker, ormsby

# Ricker (single frequency)
t, wavelet = ricker(duration=0.128, dt=0.001, f=25)

# Ormsby (bandpass: low cut, low pass, high pass, high cut)
t, wavelet = ormsby(duration=0.128, dt=0.001, f=[5, 10, 50, 60])

Synthetic Seismogram

from bruges.filters import ricker
from scipy.signal import convolve

rc = np.diff(impedance) / (impedance[:-1] + impedance[1:])  # Reflectivity
_, wavelet = ricker(0.128, 0.001, 30)
synthetic = convolve(rc, wavelet, mode='same')

Read the full file on GitHub · 190 lines

Files

What ships with it

3 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. 10d ago First seen · 190 lines · 111 tokens per session scan A 93ebd82b41a0

Subscribe to this mod's changes

bruges is a skill published in the GitHub repository SteadfastAsArt/geoscience-skills (58 stars, last pushed 5mo ago), licensed MIT. It adds 111 tokens to every session and 1,967 once invoked, about $0.0006 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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