Jev Directory
The largest free, curated directory of Jev resources.
Explore official and community-built repos, SDKs, cookbooks, tools, patterns, and guides for Jev, TypeSafe's flagship System One model. Selected entries include verified deep dives.
Choice(
instructions="Which team should handle this?",
criteria={
"returns": "Exchanges, wrong or damaged items",
"shipping": "Delivery status, delays, lost packages",
"billing": "Charges, invoices, payment problems",
},
)Example Jev answer
confidence 0.42
- Returns
- 61%
- Billing
- 35%
Inside the Jev directory
2231 Jev entries from 148 source sites, tagged and verified by hand. Every entry carries a verified deep dive. Last updated Oct 12, 2026.
Jev by category
Jev by format
- Docs89
- Repos & sites1820
- Videos73
- Posts88
- Articles119
- Playgrounds42
Jev by topic
Start with a Jev primitiveChoice— pick one of your optionsScore— rate on an ordered scaleNoul— answer yes or no
Featured Jev resources
Starting points for building with Jev.
Published evaluations of four automation workflows, security incidents, agent trace observability, invoice processing, and customer service, comparing Jev and frontier LLMs as structured workflows versus single prompts.
Jev Practices & PatternsDocs#official#benchmarks#evaluation
Official
6GitHub stars
.NET SDK for the System One API with typed question sets, HttpClientFactory and dependency-injection wiring, plus Microsoft.Extensions.AI guardrail, routing, tool, and evaluator adapters.
Jev Repos & SDKs#community#sdk#csharp
Community
Hawxy/TypeSafeAI.NetC#
Hawxy/TypeSafeAI.NetC#0GitHub stars
A NativeAOT-ready .NET SDK generated from TypeSafe's OpenAPI definition, with typed question sets, batching, dependency injection, and Microsoft.Extensions.AI integrations.
Jev Repos & SDKs#community#sdk#csharp
Community
tryAGI/TypeSafeAIC#
tryAGI/TypeSafeAIC#Latest Jev additions
The newest Jev entries in the directory, official and community.
Browse Jev by category
11 Jev categories, from official SDKs to community tools.
Repos & SDKs202Client libraries, adapters, and source code you can build on with Jev, from the official Python and TypeScript SDKs to community ports in Go, .NET, and PHP.Integrations & Adapters145Framework, platform, gateway, and database integrations that put Jev inside the stack you already run, from LangChain and Pydantic AI to Postgres and Home Assistant.Agents & MCP302Agent runtimes, coding-agent gates and routers, MCP servers, and skill or context tooling that hand an agent Jev's typed decisions.Tools & CLIs447Standalone Jev CLIs, desktop apps, playgrounds, and utilities you run directly, from shell history and semantic search to dashboards and meters.Cookbooks91Official, runnable Jev recipes that show what decision models are good at, each with its own datasets, latencies, and numbers.Demos & Experiments363Playable demos, games, simulators, and experiments that put Jev in the loop, from Mario and drones to moderation firehoses and trading bots.Practices & Patterns248How to design Jev states, questions, and confidence gates the right way, from the official patterns to the failure modes worth designing around.Guides & Articles224Documentation, write-ups, and community hubs for learning Jev, from the canonical docs to independent tutorials and reviews.Benchmarks & Evaluations55Benchmarks, calibration studies, independent evaluations, and observability write-ups that measure how Jev actually behaves.Models & Reimplementations99Open reimplementations of Jev, retrained heads on small models, and inference-time tricks that reproduce the System One shape with other weights.Media & Talks55Videos, talks, podcasts, and news coverage about building with Jev.
Jev articles
Original guides to designing with Jev, grounded in the docs and cookbooks.
Most Jev accuracy problems are state problems. What belongs in a state, what is a pre-made judgment to leave out, and why naming the slice you ask about matters more than the wording.
Jev Practices & Patterns#state#design#primitives
Read article
A Noul returns one number and no separate confidence. How to read the value, pin its boundary with criteria, split compound questions, and set a per-action threshold that matches the cost of being wrong.
Jev Practices & Patterns#noul#primitives#confidence
Read article
A Score is a weighted position, not a ruler. Why the number can land between levels, why levels are judged separately, and how to combine several atomic scores in code instead of one crowded rubric.
Jev Practices & Patterns#score#primitives#scoring
Read article
Jev glossary
164 plain-language definitions for the terms you meet building with Jev, from primitives to jagged edges.
- ChoicePick one option from a set you define; returns the selected option, a probability for every option, and confidence.
- ScoreRate the state against 2 to 10 ordered levels; returns a probability-weighted position, per-level probabilities, and confidence.
- NoulThe yes/no primitive: one probability from 0 to 1, where the value is the answer and no separate confidence is returned.
- ConfidenceA 0-1 number on every Choice and Score answer that collapses the probability distribution into one certainty score.
- CalibrationThe property that outcomes given a probability of 0.2 occur about 20% of the time, measured across many predictions.
- Speculative fan-outAsk every question the system might need in one request — including ones only some branches use — and let code discard the rest.
Jev community on X
What builders are saying and shipping with Jev.