creating-mods SKILL.md skillA
creating-mods from letta-ai/letta-code is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add letta-ai/letta-code/creating-mods@git:20261028.a8f8e4bPins git:20261028.a8f8e4b in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- letta-ai/letta-code
- Path
src/skills/builtin/creating-mods/SKILL.md- Versions recorded
- 6
- Latest version
- git:20261028.a8f8e4b, committed Oct 28, 2026
- First version recorded
- Jun 25, 2026
- Size
- 9,985 bytes
- Repository stars
- 3,759
- License
- Apache-2.0
Creates and edits trusted local Letta Code mods, including tools, slash commands, local-only model providers, lifecycle/turn events, scoped conversation helpers, panels, and capability-gated behavior. Use when asked to make a mod, add an agent-callable tool, add a slash command, add a local provider/model adapter, transform turns, react to app events, or add lightweight mod UI outside the dedicated /statusline flow.
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
# Creating Mods
Use this skill to create or update trusted Letta Code mod files. Mods are trusted local code that add small composable capabilities through mod APIs, not by importing app internals. Dynamic agent/conversation/workspace/model state is passed as `ctx` to tool, command, event, and permission callbacks (panels receive live `agent`/`model` in their render context); do not read mutable global context for model-callable behavior. Prefer scoped handles (`ctx.conversation`, `ctx.cwd`, `ctx.agent`) and guard optional UI with `letta.capabilities`.
Capabilities vary by surface — not every surface loads every capability. The TUI/headless host can load tools, commands, events, UI, and providers; the desktop listener loads tools, commands, providers, and tool/turn events, but not panel UI. Always guard each registration on the capabilities its behavior needs.
## Choose where the mod file lives
Default to a single mod file unless the user asks for something larger.
| Location | Use when |
| --- | --- |
| `${LETTA_CONFIG_DIR:-$HOME/.letta}/mods/foo.ts` | The behavior should apply to local sessions for the active product on this machine. Use this by default. |
…Read the whole file at its exact version.
How to install
mdr add letta-ai/letta-code/creating-mods@sha256:b80d76309b1b0544The line at the top of this page pins the label git:20261028.a8f8e4b, 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_4lyrm4errcy75xqa)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 6 versions of this file, between Jun 25, 2026 and Oct 28, 2026, about one every 25 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261028.a8f8e4b latest | 2026-10-28 | a8f8e4b | 9,985 B | A | view · diff |
| git:20260721.f52bbd8 | 2026-07-21 | f52bbd8 | 9,880 B | A | view · diff |
| git:20260703.50ab5e9 | 2026-07-03 | 50ab5e9 | 9,870 B | A | view · diff |
| git:20260626.f3c17f0 | 2026-06-26 | f3c17f0 | 9,839 B | A | view · diff |
| git:20260625.085b469 | 2026-06-25 | 085b469 | 9,094 B | A | view · diff |
| git:20260625.cc690d1 | 2026-06-25 | cc690d1 | 9,144 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 (9985 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
letta-ai/letta-code · 3,759 stars · license Apache-2.0 · pushed 2026-11-02 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_4lyrm4errcy75xqa GET https://markdownregistry.com/api/v1/resolve?ref=letta-ai/letta-code/creating-mods GET https://markdownregistry.com/api/v1/blob/b80d76309b1b0544b3663ca27b39476d8fff99a82b89b701a139f4b8eb4ce98a
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.