fp-immutability SKILL.md skillA
fp-immutability from pantheon-org/tekhne is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add pantheon-org/tekhne/fp-immutability@git:20260710.2a8ef15Pins git:20260710.2a8ef15 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- pantheon-org/tekhne
- Path
skills/software-engineering/fp-immutability/SKILL.md- Versions recorded
- 2
- Latest version
- git:20260710.2a8ef15, committed Jul 10, 2026
- First version recorded
- Jul 10, 2026
- Size
- 9,392 bytes
- Repository stars
- 10
- License
- MIT
Apply immutability principles across languages for safer, more predictable code.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Immutability Principles
Immutability is a cornerstone of functional programming where data cannot be modified after creation. Instead of changing existing values, you create new values. This approach eliminates entire classes of bugs related to shared mutable state, makes code easier to reason about, and enables safe concurrent programming.
## Core Concepts of Immutability
Immutable data has several key benefits:
1. **Predictability**: Data doesn't change unexpectedly
2. **Thread Safety**: No race conditions with immutable data
3. **Easier Debugging**: State changes are explicit and traceable
4. **Temporal Logic**: Can keep historical versions of data
5. **Caching**: Safe to cache references to immutable data
### JavaScript: Immutability Patterns
```javascript
// MUTABLE APPROACH (avoid)
const user = {
name: 'Alice',
email: 'alice@example.com',
addresses: []
};
function addAddress(user, address) {
user.addresses.push(address); // Mutation!
return user;
}
// IMMUTABLE APPROACH (prefer)
const userImmutable = {
name: 'Alice',
email: 'alice@example.com',
addresses: []
};
function addAddressImmutable(user, address) {
return {
...user,
…Read the whole file at its exact version.
How to install
mdr add pantheon-org/tekhne/fp-immutability@sha256:cdb22cf864973af2The line at the top of this page pins the label git:20260710.2a8ef15, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_b6r4qnyg65keq6vv)
1 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, all committed on Jul 10, 2026.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260710.2a8ef15 latest | 2026-07-10 | 2a8ef15 | 9,392 B | A | view · diff |
| git:20260710.48d97ba | 2026-07-10 | 48d97ba | 8,231 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (9392 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
pantheon-org/tekhne · 10 stars · license MIT · pushed 2026-10-21 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_b6r4qnyg65keq6vv GET https://markdownregistry.com/api/v1/resolve?ref=pantheon-org/tekhne/fp-immutability GET https://markdownregistry.com/api/v1/blob/cdb22cf864973af22501a291808266022c7e065520f66cb9a9e4e947a8e95b11
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.