pydantic-ai-harness SKILL.md skillA
pydantic-ai-harness from pydantic/pydantic-ai-harness is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add pydantic/pydantic-ai-harness/pydantic-ai-harness@v0.1.0Pins v0.1.0 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- pydantic/pydantic-ai-harness
- Path
pydantic_ai_harness/.agents/skills/pydantic-ai-harness/SKILL.md- Versions recorded
- 5
- Latest version
- v0.1.0, committed Jul 28, 2026
- First version recorded
- Jul 11, 2026
- Size
- 7,595 bytes
- Repository stars
- 960
- License
- MIT
Extend Pydantic AI agents with batteries-included capabilities from pydantic-ai-harness -- Code Mode (collapse many tool calls into one sandboxed Python execution), a filesystem and shell, sub-agents, planning, context compaction, and more. Use when the user mentions pydantic-ai-harness, CodeMode, Monty, code mode, or tool sandboxing, when they want first-party filesystem/shell/sub-agent/planning/compaction capabilities for a Pydantic AI agent, when they want an agent to run agent-written…
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
# Building with Pydantic AI Harness Pydantic AI Harness is the official capability library for Pydantic AI. Capabilities that need model or framework support -- and those fundamental to every agent -- live in core `pydantic-ai`; optional, batteries-included capabilities live here. Both are composed onto an agent through the same `capabilities=[...]` API. This skill covers the capabilities shipped by `pydantic-ai-harness`. For the core framework -- agents, tools, structured output, hooks, and testing -- use the `building-pydantic-ai-agents` skill instead. ## When to Use This Skill Invoke this skill when: - The user mentions `pydantic-ai-harness`, `CodeMode`, code mode, or the Monty sandbox - An agent makes many sequential tool calls that could collapse into one sandboxed Python execution - The user wants the model to write Python that loops, branches, aggregates, or parallelizes tool calls with `asyncio.gather` - The user asks to sandbox or constrain the code an agent runs Do **not** use this skill for: - Core Pydantic AI usage -- building agents, adding tools, structured output, streaming, or testing (use `building-pydantic-ai-agents`) …
Read the whole file at its exact version.
How to install
mdr add pydantic/pydantic-ai-harness/pydantic-ai-harness@sha256:1492bbc887d264d6The line at the top of this page pins the label v0.1.0, 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_wf77gggyqbvwuojv)
2 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 5 versions of this file, between Jul 11, 2026 and Jul 28, 2026, about one every 4 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| v0.1.0 latest | 2026-07-28 | 6d2cb39 | 7,595 B | A | view · diff |
| v0.1.0 | 2026-07-26 | a3057d5 | 7,568 B | A | view · diff |
| v0.1.0 | 2026-07-24 | 4bb5481 | 7,566 B | A | view · diff |
| v0.1.0 | 2026-07-14 | 73513a6 | 7,582 B | A | view · diff |
| v0.1.0 | 2026-07-11 | 310ffad | 7,700 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 (7595 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
pydantic/pydantic-ai-harness · 960 stars · license MIT · pushed 2026-10-02 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_wf77gggyqbvwuojv GET https://markdownregistry.com/api/v1/resolve?ref=pydantic/pydantic-ai-harness/pydantic-ai-harness GET https://markdownregistry.com/api/v1/blob/1492bbc887d264d6e93dd8ad514c3c5ae1f4e5fac41d8e1267287900d8877e61
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.