migrating-deep-agents-to-pydantic-ai-harness SKILL.md skillA
migrating-deep-agents-to-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/migrating-deep-agents-to-pydantic-ai-harness@git:20260915.ea12b7fPins git:20260915.ea12b7f 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/migrating-deep-agents-to-pydantic-ai-harness/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260915.ea12b7f, committed Sep 15, 2026
- Size
- 6,641 bytes
- Repository stars
- 960
- License
- MIT
Migrate Python LangChain Deep Agents applications to Pydantic AI and Pydantic AI Harness. Use when the source uses the upstream `deepagents` package or demonstrably reproduces its middleware, backends, skills, memory, subagents, or sandbox contracts. Use `migrating-langchain-to-pydantic-ai` for plain LangChain, LangGraph, or LCEL migrations and `pydantic-ai-harness` for greenfield Harness usage.
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
# Migrate Deep Agents to Pydantic AI Harness Preserve the application's observed contracts, not the shape of `create_deep_agent`. Compose Pydantic AI primitives and Harness capabilities; keep infrastructure with the application that already owns it. ## Establish the source contract 1. Resolve the `deepagents` import origin before applying these mappings. Route a local module or project-owned `create_deep_agent` to the ordinary LangChain migration only when its implementation has ordinary LangChain or LangGraph semantics; vendored implementations that reproduce Deep Agents contracts remain in scope. Read repository instructions, manifests, lockfiles, tests, runtime entrypoints, and the resolved source. Record exact Deep Agents, LangChain, LangGraph, Pydantic AI, and Harness versions. If the locked source is unavailable, reproduce its environment without changing the target lockfile. If that is not possible, mark affected behavior unverified and do not claim parity. …
Read the whole file at its exact version.
How to install
mdr add pydantic/pydantic-ai-harness/migrating-deep-agents-to-pydantic-ai-harness@sha256:21a58bbcc65d9470The line at the top of this page pins the label git:20260915.ea12b7f, 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_yz7ovhancm5z6pdx)
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Versions
The registry has recorded 1 version of this file, committed on Sep 15, 2026.
Audit of the latest version
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- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (6641 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_yz7ovhancm5z6pdx GET https://markdownregistry.com/api/v1/resolve?ref=pydantic/pydantic-ai-harness/migrating-deep-agents-to-pydantic-ai-harness GET https://markdownregistry.com/api/v1/blob/21a58bbcc65d94702db2170e184168908f633c9ffd4872882e04bebc0e58f013
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.