Every premium and members-only resource for $9.99/month, as a no-commitment subscription. See the plans

PalateKit

Sign in
Menu

Request a resource

Describe the resource you are missing in one sentence. We will email you when it is published.

0 / 280

A page, a video or an image online.

Unlock PalateKit

Unlock everything

Plan

Paying means accepting our terms of sale.

Secure payment by Stripe. Receipts and invoices sent by email.

Welcome back

Sign in to install, download or save this resource. A free account is enough for free resources.

Deterministic local test loop for LangChain v1.0.0

Use this resource to write reproducible LangChain tests locally

New

  • 397 downloads
  • 231 likes
  • 184 saves

Free

Install with the CLI

In a terminal, from the folder you want:

npx --yes palatekit@latest install langchain-deterministic-test-loop

With no option, the skill goes to ~/.agents/skills/; add --agent claude-code (or codex, cursor…) to target an agent.

First time: connect the CLI with

npx --yes palatekit@latest login

The agent swaps the live model for a fake one in unit tests, wires pytest fixtures into the chains and records integration calls as VCR cassettes with key redaction. You get a ready-to-use pytest configuration.

Mostly picked by

Updated November 2, 2026

Card for the “Deterministic local test loop for LangChain” skill

Details

Works in
Install guides
Generates with
Your agent's model
Licence
MIT

Similar resources

View all

What you get

  • references/fake-model-fixtures.md : fake models and chain fixtures
  • references/vcr-cassette-hygiene.md : VCR cassettes without exposed keys
  • references/pytest-config.md : markers and warning filters

Good fit for

  • A chain test fails randomly because of the model
  • You want integration tests to be reproducible

Not for

    Tags

    • langchain
    • pytest
    • tests
    • vcr
    • fixtures

    About

    You say

    “Make my LangChain chain tests deterministic with a fake model and VCR cassettes.”

    Card for the “Deterministic local test loop for LangChain” skill

    Skill published by Jeremy Longshore <jeremy@intentsolutions.io> under the MIT license, delivered in its original version.

    Show more

    How to use it

    1. Install the skill in your agent's skills folder
    2. Ask your agent to write reproducible LangChain tests locally
    3. Review and adjust the result

    Content preview

    Files

    • LICENSE1.1 KB
    • NOTICE-PALATEKIT.md0.5 KB
    • references/fake-model-fixtures.md6.3 KB
    • references/langgraph-test-patterns.md6.7 KB
    • references/one-pager.md3.4 KB
    • references/pytest-config.md5.3 KB
    • references/vcr-cassette-hygiene.md5.1 KB
    • SKILL.md16.3 KB

    Origin and licence

    Listed unmodified

    Author
    Jeremy Longshore <jeremy@intentsolutions.io>
    Source
    github.com/jeremylongshore/tons-of-skills-marketplace/tree/ab85a061f7bcc039dac13ee193de7a4cd4388571/skills/.curated/langchain-local-dev-loop
    Licence
    MIT

    Notice

    « langchain-local-dev-loop » (Jeremy Longshore <jeremy@intentsolutions.io>, MIT) livré dans sa version d'origine : fiche en français et en anglais par PalateKit.

    User reviews

    –

    No ratings yet

    Loading reviews…

    Delete your review?

    Your rating and comment will be removed from the page.