What is ag-ui built with?

Q: Which repos have a stack like ag-ui's?

The ones that share most of its stack: vectorize-io/hindsight, Significant-Gravitas/AutoGPT, and bytedance/deer-flow.

ag-ui is a Python repo built with ASP.NET Core, FastAPI, Spring, activity-compose, AIOHTTP, and 8 more. It uses AI through go, Microsoft.Extensions.AI.Abstractions, openai-agents, spring-ai-bom, spring-ai-client-chat, and 19 more, measures its use with PostHog, makes its content with coil-compose, streamdown, markdown-it, and yaml, validates its data with Pydantic, Zod, zod-to-json-schema, @cfworker/json-schema, and Ajv, is tested with io.ktor:ktor-client-mock, junit-bom, org.jetbrains.kotlinx:kotlinx-coroutines-test, reactor-test, org.junit.jupiter:junit-jupiter, and 4 more, deploys with io.ktor:ktor-client-logging, slf4j-simple, github.com/sirupsen/logrus, and log, and uses @mastra/libsql and MCP. It has 879,462 written lines, with 1,756 test files.

Read on November 7, 2026, at commit 37b4da9. Read it as markdown

Frontend

The base 2

React60 files · in apps/dojo/package.json
Next.js11 files · in apps/dojo/package.json

Styles 4

Interface 6

Radix UI4 files
@copilotkit/react-ui1 file
@monaco-editor/react1 file
embla-carousel-react1 file
tiptap1 file
@a2ui/web_core1 file

Icons 2

Lucide10 files
@phosphor-icons/react1 file

Backend

The base 5

FastAPI13 files
Hono3 files
Express2 files · in apps/dojo/package.json
Spring2 files
ASP.NET Core

AI 24

copilotkit37 files
mastra19 files
LangChain16 files
google-adk10 files
@strands-agents/sdk8 files
CrewAI7 files
@a2a-js/sdk6 files
LangGraph4 files
litellm4 files
ai2 files
@copilotkit/runtime1 file
@langchain/openai1 file

12 more

mcp1 file
go
openai-agents
strands-agents
Microsoft.Extensions.AI17 files
ag-ui-a2ui-toolkit7 files
google-antigravity6 files
@omnara/sdk1 file
langroid1 file
Microsoft.Extensions.AI.Abstractions
spring-ai-bom
spring-ai-client-chat

Data 1

@mastra/libsql1 file

Services 2

PostHog6 files · apps/dojo/instrumentation-client.ts, line 1
MCP3 files · integrations/claude-agent-sdk/typescript/src/loopback-mcp.ts, line 3

Support

The base 6

Tokio1 file
uvicorn1 file
AIOHTTP
activity-compose
core-ktx
java-server

Content 4

Validation 5

Zod36 files
Pydantic10 files
@cfworker/json-schema1 file
Ajv1 file
zod-to-json-schema1 file

Testing 9

Vitest343 files
github.com/stretchr/testify13 files
@copilotkit/aimock1 file
org.springframework.boot:spring-boot-starter-test1 file
io.ktor:ktor-client-mock
org.jetbrains.kotlinx:kotlinx-coroutines-test
org.junit.jupiter:junit-jupiter30 files
junit-bom
reactor-test

Deploy 4

io.ktor:ktor-client-logging
github.com/sirupsen/logrus2 files
log2 files
slf4j-simple

Tools 8

esbuild1 file
Inquirer1 file
Prettier1 file
sorbet-runtime7 files
concurrently2 files
commander1 file
giget1 file
Grpc.Tools

Other 41

rxjs40 files
Ktor6 files
io.ktor:ktor-serialization-kotlinx-json5 files
Google2 files
json2 files
@bufbuild/protobuf1 file
asyncio
io.ktor:ktor-client-content-negotiation
JetBrains
System.Text.Json59 files
co.touchlab:kermit13 files
serde_json10 files

29 more

serde8 files
com.fasterxml.jackson.core:jackson-databind6 files
async-trait4 files
fast-json-patch4 files
futures4 files
http3 files
reqwest3 files
thiserror3 files
uuid3 files
Google.Protobuf2 files
sse-starlette2 files
untruncate-json2 files
bytes1 file
clarinet1 file
clsx1 file
compare-versions1 file
cors1 file
dedent1 file
diff1 file
httpx1 file
json-patch1 file
json-repair1 file
meta1 file
System.Net.ServerSentEvents1 file
ag-ui-protocol
coil-network-ktor3
kotlinx-serialization-json
reactor-core
s

Other repos with a similar stack

Ordered by how much of its stack they share with ag-ui, then by stars.

vectorize-iohindsight
59k
Hindsight: Agent Memory That Learns
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Significant-GravitasAutoGPT
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AutoGPT is the vision of accessible AI for everyone, to use and to build on. Our mission is to provide the tools, so that you can focus on what matters.
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bytedancedeer-flow
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An open-source long-horizon SuperAgent harness that researches, codes, and creates. With the help of sandboxes, memories, tools, skill, subagents and message gateway, it handles different levels of tasks that could take minutes to hours.
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《深入理解 AI Agent：设计原理与工程实践》（李博杰著）开源主仓库：全书正文、编译版 PDF 与按章配套代码
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Frequently asked questions

What language is ag-ui written in?

ag-ui is written in Python, with 879,462 written lines.

What framework does ag-ui use?

ag-ui is built with ASP.NET Core, FastAPI, Spring, activity-compose, AIOHTTP, core-ktx, java-server, Tokio, uvicorn, React, Next.js, Express, and Hono.

Does ag-ui use AI?

Yes. ag-ui uses AI through go, Microsoft.Extensions.AI.Abstractions, openai-agents, spring-ai-bom, spring-ai-client-chat, strands-agents, Microsoft.Extensions.AI, google-adk, ag-ui-a2ui-toolkit, CrewAI, google-antigravity, LangChain, LangGraph, litellm, langroid, mcp, copilotkit, mastra, @a2a-js/sdk, @langchain/openai, @strands-agents/sdk, ai, @omnara/sdk, and @copilotkit/runtime.

What services does ag-ui use?

ag-ui measures its use with PostHog and uses @mastra/libsql and MCP.

The proof: apps/dojo/instrumentation-client.ts, line 1

Does ag-ui have tests?

Yes. ag-ui has 1,756 test files and is tested with io.ktor:ktor-client-mock, junit-bom, org.jetbrains.kotlinx:kotlinx-coroutines-test, reactor-test, org.junit.jupiter:junit-jupiter, github.com/stretchr/testify, org.springframework.boot:spring-boot-starter-test, Vitest, and @copilotkit/aimock.

Which repos have a stack like ag-ui's?

The ones that share most of its stack:vectorize-io/hindsight Significant-Gravitas/AutoGPT bytedance/deer-flow