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Resources

Resources for people building with AI agents

Records we built ourselves and open tools we point to. Read what each one is, and what to check before adopting it. We do not rank or benchmark open source — only what it is for and what to check.

Last checked 2026-10-17 · rechecked monthly

Made by us

Our own write-ups, public assets, and videos.

Build notes and measured write-ups

  • Marblo 빌드 노트

    A development log series: one release note per Marblo release, plus a deep-dive post per feature.

    For enterprise adoption

    Shows where approval gates sit when several agents run in parallel, as actual design decisions. Start from the release note and follow links to the feature posts.

    Checked
  • resume 플래그는 하네스마다 다르다 (실측)

    A hands-on comparison of how Codex, Grok, and Claude Code resume sessions, with the versions tested.

    For enterprise adoption

    If you plan to mix several coding agents in one workflow, this shows where a failed resume ends the process instead of warning.

    Checked
  • 에이전트가 일하는 중인지 어떻게 아나 (실측)

    Why judging agent activity from terminal output misleads in both directions, and how to define state by boundaries instead.

    For enterprise adoption

    Useful when deciding how to tell "stalled" from "working" for long-running agents in operations.

    Checked
  • 에이전트별 비용 추적의 사각지대 (실측)

    A diagnosis of the wiring point that fails silently when you add a new harness to per-agent cost tracking.

    For enterprise adoption

    For teams splitting AI spend by department or agent: a checklist order for when the cost table comes back empty.

    Checked

Public assets

  • Marblo 오픈 생태계 (/open)

    A registry of skills, agent definitions, MCP servers, knowledge packs, and workflows published as plain files.

    For enterprise adoption

    Each item carries a grade (official, verified, community); read the grade definitions before bringing anything in-house. Community items are unreviewed.

    Checked
  • 보안 · 전송 범위 (/security)

    What Marblo sends off the machine, which settings turn it off, and answers for a security review.

    For enterprise adoption

    Meant to be handed to a security team as a link. It also lists what is not yet true.

    Checked

Videos

Open-source projects

Repository addresses and licenses were rechecked on the date shown. Archived repositories and repositories whose license could not be confirmed are left out.

Reading the license labels

'Conditional' marks repositories where the license differs by directory or file, or where extra conditions apply to offering it as a service or to branding. Items without the label use a single permissive license such as MIT or Apache-2.0 across the repository. This page is not legal advice; read the LICENSE file before adopting.

Agent frameworks

  • langchain-ai/langgraph

    A framework for building stateful agent flows as graphs.

    For enterprise adoption

    For writing workflows with approval steps and retries explicitly in code. The flow stays auditable, but there is a learning curve, so keep the pilot narrow.

    License
    MIT
    Checked
  • crewAIInc/crewAI

    A framework for setting up several role-based agents that work together.

    For enterprise adoption

    Fits prototypes of role-split work such as research, drafting, and review. Set call limits and logging first; cost and tracing get harder as agents multiply.

    License
    MIT
    Checked
  • microsoft/autogen

    A programming framework for agents that work by conversing with one another.

    For enterprise adoption

    For research and prototypes of multi-agent conversation. Check the repository notes for how it relates to Microsoft Agent Framework.

    License
    ConditionalMIT + CC-BY-4.0The repository is labeled CC-BY-4.0; the code is MIT under a separate LICENSE-CODE file. Which applies depends on what you reuse.
    Checked
  • microsoft/agent-framework

    A framework for building and deploying agents and multi-agent workflows (Python and .NET).

    For enterprise adoption

    A candidate for organizations running both Python and .NET. It is relatively new, so pin versions and track the changelog.

    License
    MIT
    Checked
  • openai/openai-agents-python

    A lightweight multi-agent framework built around tool calls and hand-offs between agents.

    For enterprise adoption

    A small starting point for tool calls and hand-offs. If you may switch model providers, check how far support for other models goes.

    License
    MIT
    Checked
  • pydantic/pydantic-ai

    A Python library for agents whose output is validated against typed schemas.

    For enterprise adoption

    Fits work where agent output feeds other systems directly. Schema validation guarantees shape, not correctness, so evaluate content separately.

    License
    MIT
    Checked
  • huggingface/smolagents

    A minimal library where agents act by writing code.

    For enterprise adoption

    Small enough for teaching the concepts. Because it executes code, connecting it to production data requires an isolated sandbox.

    License
    Apache-2.0
    Checked
  • run-llama/llama_index

    An LLM application framework centered on document processing and data connectors.

    For enterprise adoption

    For connecting internal documents to search and Q&A (RAG). Document-level permissions must be designed into indexing separately.

    License
    MIT
    Checked
  • deepset-ai/haystack

    An orchestration framework that assembles retrieval and agent pipelines from components.

    For enterprise adoption

    Components are easy to swap and inspect. Turn on per-component logging so you can see which documents fed each answer.

    License
    Apache-2.0
    Checked
  • mastra-ai/mastra

    A TypeScript framework for AI applications and agents.

    For enterprise adoption

    A candidate when a web team wants to stay in TypeScript. Read the ee/ license separately if you plan to use those features.

    License
    ConditionalApache-2.0 + ee/Anything under an ee/ directory uses a separate license (ee/LICENSE); the rest is Apache-2.0.
    Checked

MCP and tool connections

  • modelcontextprotocol/servers

    A collection of reference implementations of Model Context Protocol servers.

    For enterprise adoption

    A baseline for learning how agents use tools such as files and search. Reference code may not cover production security, so narrow permissions yourself.

    License
    ConditionalMIT → Apache-2.0New contributions are Apache-2.0; earlier contributions without relicensing consent stay MIT. Both are permissive, but files may differ.
    Checked
  • modelcontextprotocol/python-sdk

    The official Python SDK for building MCP servers and clients.

    For enterprise adoption

    The starting point for exposing internal systems as MCP tools. Separate read and write per tool and log every call.

    License
    MIT
    Checked
  • github/github-mcp-server

    GitHub's official MCP server.

    For enterprise adoption

    For delegating issue and PR work to agents. Start with a read-only token and scope write access per repository.

    License
    MIT
    Checked
  • microsoft/playwright-mcp

    An MCP server that exposes browser automation as tools.

    For enterprise adoption

    For web checks and repetitive form work. It hands a logged-in session to the agent, so separate accounts and restrict reachable domains.

    License
    Apache-2.0
    Checked

Coding agents

  • openai/codex

    A coding agent that runs in the terminal.

    For enterprise adoption

    For developer-team pilots. Agree on how agent-run commands are approved and how working directories are isolated.

    License
    Apache-2.0
    Checked
  • google-gemini/gemini-cli

    An agent CLI for using Gemini models from the terminal.

    For enterprise adoption

    For running the same task side by side with other vendors’ CLIs. Include what code leaves for an external model in your security review.

    License
    Apache-2.0
    Checked
  • OpenHands/OpenHands

    An agent platform where AI carries out software development tasks.

    For enterprise adoption

    Fits experiments in delegating work issue by issue. Check in the install docs whether it runs in containers and how outbound network access is blocked.

    License
    MIT
    Checked
  • cline/cline

    An autonomous coding agent available as an IDE extension, CLI, and SDK.

    For enterprise adoption

    Works step by step inside the IDE with approvals. Align extension-install policy and API key handling with internal rules.

    License
    Apache-2.0
    Checked
  • Aider-AI/aider

    An AI pair-programming tool for the terminal.

    For enterprise adoption

    Changes land as git commits, which keeps review simple. As of the check date the last push was in May 2026, so look at recent issue and release activity first.

    License
    Apache-2.0
    Checked
  • aaif-goose/goose

    An extensible agent that goes beyond suggestions to install, run, edit, and test.

    For enterprise adoption

    For experiments extending an agent beyond development via extensions. The repository moved (formerly block/goose); this links to the current address.

    License
    Apache-2.0
    Checked

Evaluation, observability, gateways

  • langfuse/langfuse

    An observability platform for tracing, evaluating, and improving LLM applications.

    For enterprise adoption

    Acts as an audit log of which input produced which answer. Logs will contain personal data, so decide masking and retention first.

    License
    ConditionalMIT + ee/The ee/, web/src/ee/, and worker/src/ee/ directories use a separate license (ee/LICENSE); the rest is MIT.
    Checked
  • Arize-ai/phoenix

    A tool for observing and evaluating AI applications.

    For enterprise adoption

    For tracking experiments in-house. Get legal review before offering it to customers as a service.

    License
    ConditionalElastic License 2.0Not an OSI open-source license. It restricts offering the software to third parties as a hosted or managed service.
    Checked
  • confident-ai/deepeval

    An evaluation framework that checks LLM output repeatedly, the way tests do.

    For enterprise adoption

    For pre-release regression checks. Scores depend on configuration, so define and document the criteria yourselves.

    License
    Apache-2.0
    Checked
  • vibrantlabsai/ragas

    An evaluation toolkit for LLM applications, often used for RAG answers.

    For enterprise adoption

    Good for learning how to check RAG answers against sources. As of the check date the last push was in February 2026 and the repository has moved, so confirm current activity.

    License
    Apache-2.0
    Checked
  • promptfoo/promptfoo

    A tool for testing prompts, agents, and RAG, including red-team checks.

    For enterprise adoption

    For finding weak prompts before release. It calls external models, so keep real personal data out of test sets.

    License
    MIT
    Checked
  • BerriAI/litellm

    A gateway that lets you call many LLM providers through one API format.

    For enterprise adoption

    A middle layer so switching providers does not mean rewriting the app. Every call passes through it, so key management, access control, and log retention are the core design.

    License
    ConditionalMIT + enterprise/The enterprise/ directory uses a separate license (enterprise/LICENSE); the rest is MIT.
    Checked

Automation and app platforms

  • n8n-io/n8n

    A workflow automation platform with AI features.

    For enterprise adoption

    For automating repetitive work in non-engineering teams. Check the license before offering it to external customers.

    License
    ConditionalSustainable Use LicenseA fair-code license, not OSI open source. Files or directories with .ee in the name require a separate enterprise license.
    Checked
  • langgenius/dify

    A platform for building agent workflows and RAG in one workspace.

    For enterprise adoption

    Suits teams that want to prototype without code. Check the multi-tenant condition before any SaaS-style use.

    License
    ConditionalApache-2.0 (modified)Apache-2.0 with added conditions: no multi-tenant operation without written permission, and the frontend logo and copyright notices must stay.
    Checked
  • open-webui/open-webui

    A self-hosted AI chat interface for local models and external APIs.

    For enterprise adoption

    For standing up an internal chat UI quickly. Check the branding clause and how it integrates with your sign-in.

    License
    ConditionalOpen WebUI LicenseA custom license: BSD-3-style terms plus a branding clause. Changing the "Open WebUI" branding in larger deployments requires checking the conditions.
    Checked
  • vllm-project/vllm

    An inference and serving engine for LLMs.

    For enterprise adoption

    A candidate for serving models on your own GPUs to keep data in-house. Assumes GPU operations staff and budget.

    License
    Apache-2.0
    Checked

Documents, data, memory, browser

  • microsoft/markitdown

    A Python tool that converts Office documents and other files to Markdown.

    For enterprise adoption

    For cleaning internal documents before RAG ingestion. Sample-check for lost tables and formatting and keep a source comparison step.

    License
    MIT
    Checked
  • docling-project/docling

    A tool that converts PDFs and other documents into structures generative AI can use.

    For enterprise adoption

    A candidate for structurally complex documents. Test results on Korean-language and scanned documents yourself.

    License
    MIT
    Checked
  • unclecode/crawl4ai

    A crawler that collects web pages as LLM-ready Markdown.

    For enterprise adoption

    For automating research on public sources. Respect each site’s terms, robots policy, and copyright.

    License
    Apache-2.0
    Checked
  • chroma-core/chroma

    Vector storage and search infrastructure for AI applications.

    For enterprise adoption

    An easy store for small RAG prototypes. Design for production scale and access control separately.

    License
    Apache-2.0
    Checked
  • mem0ai/mem0

    A memory layer that gives agents persistent memory.

    For enterprise adoption

    For letting agents remember per-customer preferences and history. Memory is personal-data storage, so design a deletion path.

    License
    Apache-2.0
    Checked
  • browser-use/browser-use

    A Python library that lets AI agents operate a browser.

    For enterprise adoption

    For automation experiments on legacy web systems. The project also promotes a paid hosted service; read the open-source part separately.

    License
    MIT
    Checked

Governance and privacy

  • NVIDIA-NeMo/Guardrails

    A toolkit for adding programmable guardrails to LLM chat applications.

    For enterprise adoption

    For managing topic and format rules as code. Guardrails reduce risk but do not guarantee blocking, so pair them with separate testing.

    License
    Apache-2.0
    Checked
  • data-privacy-stack/presidio

    A framework for detecting, masking, and anonymizing personal data in text and more.

    For enterprise adoption

    For masking personal data before it reaches an LLM. Korean ID and phone formats need custom rules you test yourself. The repository has moved; this links to the current address.

    License
    MIT
    Checked

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