Coding Agent Frameworks & Patterns

Deep Research — March 31, 2026 | Focus: Simple, focused agent patterns (2–5 agents)

Contents 1. Anthropic's Official Agentic Patterns 2. SEED / PAUL / CARL / Bayes — Christopher Kahler's Approach 3. Framework Comparison Table 4. Deep Dives on Top Picks 5. Claude-Native Agent Ecosystem 6. Recommendations for Vlad

1. Anthropic's Official Agentic Patterns

From Anthropic's "Building Effective Agents" guide — five foundational patterns, plus a multi-agent composition pattern.

1. Prompt Chaining

Sequential task execution — output of step N feeds into step N+1.

When: Clear linear dependencies (analyze → summarize → format)

Agents: 1 (single agent, multiple steps)

2. Routing

Initial classifier directs requests to specialized handlers.

When: Different task types need different expertise (support triage)

Agents: 1 router + N specialists

3. Parallelization

Multiple independent tasks executed simultaneously, results merged.

When: Tasks don't depend on each other

Agents: N parallel workers

4. Orchestrator-Workers ⭐

Central orchestrator (Opus) breaks tasks down, delegates to workers (Sonnet) in parallel, synthesizes results.

When: Complex research/analysis requiring decomposition and synthesis

Agents: 1 orchestrator + N workers

Cookbook: orchestrator_workers.ipynb

5. Evaluator-Optimizer

Generator produces output → Evaluator scores quality → Generator refines. Iterative loop.

When: Quality refinement through feedback loops

Agents: 2 (generator + evaluator)

6. Planner → Generator → QA (Multi-Agent Composition)

PM/Planner specs the task → Developer/Generator builds → QA reviews from scratch → PM finalizes.

When: Software development workflows needing multiple perspectives

Agents: 3 (planner + generator + reviewer)

The two patterns Vlad likes:

Pattern A — Orchestrator-Workers: Research with multiple Sonnet instances in parallel → One Opus model synthesizes all findings into a final result. Anthropic reports 90.2% improvement on internal research evals.

Pattern B — Planner-Generator-QA: PM hands task to developer agent → Developer builds → QA agent starts from scratch and reviews → PM finalizes status. Maps to the Developer-QA pattern.
PM / Planner
(Opus)
Developer
(Sonnet)
QA Agent
(Sonnet, fresh context)
PM Finalizes
(Opus)

2. SEED / PAUL / CARL / Bayes — Christopher Kahler's Approach

Christopher Kahler built a modular agent ecosystem for Claude Code that emphasizes focused, single-purpose agents with clear separation of concerns.

SEED — Project Incubation

Initial project scaffolding and discovery. Generates project structure, identifies dependencies, establishes baseline context.

Output: Project skeleton with organized file hierarchy

PAUL — Plan-Apply-Unify Loop

Core development cycle orchestration. Plans steps → applies changes → unifies results across modules. Three-phase iterative loop.

Output: Coherent, integrated changes across codebase

CARL — Context Augmentation & Reinforcement Layer

Dynamic context management. Augments agent context with domain-specific rules via just-in-time rule injection.

Output: Enriched context for smarter agent decisions

Bayes — Guided Exploration

Type-aware exploration using probabilistic reasoning. Guides agent decisions through Bayesian inference across solution spaces.

Output: Ranked exploration paths with confidence scores

Kahler's Philosophy: Composable, focused agents over monolithic systems. Each agent has one clear job. They form a pipeline: SEED initializes → PAUL executes dev loop → CARL enriches context continuously → Bayes guides exploration decisions throughout. Headless context handoff between agent systems.

3. Framework Comparison Table

Sorted by relevance to simple, focused agent patterns (2–5 agents). Star counts approximate as of March 2026.

Framework Type Stars Agent Pattern # Agents Claude Support Status Key Differentiator
Claude Code
Built-in Agent tool
SDK Native Orchestrator-Workers, sub-agents with model selection 1–5 ✅ Native Active Built into Claude Code itself. Spawn sub-agents with different models, isolated worktrees. Zero setup.
Claude Agent SDK
Python & TypeScript
SDK Official All 5 Anthropic patterns, composable 1–N ✅ Native Active Official SDK for building custom agent systems. Programmatic orchestration with tool_use.
Aider
paul-gauthier
OSS ~27k Architect + Editor (2-model pattern) 2 ✅ Claude native Active Architect mode: strong model plans, weaker model edits. Git-aware. Pair programming in terminal.
OpenHands
(ex-OpenDevin)
OSS ~46k Event-driven orchestration + sandboxed execution 3–8 ✅ Claude support Active Docker sandbox, event stream arch, web UI. Most production-grade OSS agent.
Cline
VS Code extension
OSS ~25k Developer agent + human-in-the-loop QA 1–2 ✅ Claude native Active VS Code native. Screenshot + DOM understanding. Permission modes (ask/auto).
Roo Code
Cline fork
OSS ~8k Multi-mode agents (Code, Architect, Ask, Debug) 2–4 modes ✅ Claude support Active Cline fork with custom agent modes. Each mode = different system prompt + tool access.
SWE-agent
Princeton NLP
OSS ~15k Research → Code pipeline with tool agents 2–5 ✅ Via LLM bridge Active SWE-bench optimized. Browser, file editor, bash tools. Academic-grade agent design.
Plandex
plandex-ai
OSS ~11k Planner + Builder (plan → execute in sandbox) 2 ✅ Claude support Active Terminal-native. Plan-first approach. Protected sandbox. Diff review before applying.
Devika
stitionai
OSS ~18k Research → Hypothesis → Implementation 3–5 ✅ Claude support Active Web research phase → planning → code generation. "Open-source Devin."
Mentat
AbanteAI
OSS ~3k Developer + assistant (context-aware) 1–2 ✅ Claude API Active Terminal-native. Good codebase understanding. Git integration.
Devon
entropy-research
OSS ~3k Orchestrator + tool agents 2–3 ✅ Claude Active Shell-based. Subprocess execution. Open-source Devin alternative.
Continue.dev
continuedev
OSS ~22k IDE-integrated agent with custom commands 1–2 ✅ Claude native Active VS Code + JetBrains. Open-source Copilot alternative. Custom slash commands.
Devin
Cognition
Commercial N/A Fully autonomous agent (plan → code → test → deploy) Internal multi-agent Own model Active First "AI software engineer." Full IDE + browser + terminal. $500/mo.
Cursor
Anysphere
Commercial N/A Agent mode (plan → edit → verify) Built-in ✅ Claude Active Most adopted AI code editor. Agent mode with multi-file editing. Composer feature.
Windsurf
Codeium
Commercial N/A Cascade flow (plan → code → review) Built-in ✅ Claude Active "Cascade" agentic flow. Context-aware across codebase. Free tier.
Codex
OpenAI (May 2025)
Commercial N/A Cloud agent (sandbox → PR) Internal ❌ OpenAI only Active OpenAI's answer to Claude Code. Cloud sandbox. Creates PRs directly.
Jules
Google
Commercial N/A Async agent (issue → PR) Internal ❌ Gemini only Active Google's async coding agent. GitHub integration. Gemini-powered.

4. Deep Dives on Top Picks

Aider — The Architect Pattern

Aider's architect mode is the closest battle-tested implementation of the orchestrator-workers pattern in a coding tool. It uses a two-model setup:

Architect (Opus)
Plans changes, reasons about architecture
Editor (Sonnet)
Applies code edits based on architect's plan

This is exactly your Pattern A: strong model thinks, cheaper model executes. Git-aware, so every change is a commit. Works in terminal — no IDE dependency.

Why it matters: 27k+ stars, battle-tested by thousands of developers daily. Paul Gauthier (creator) has benchmarked it extensively on SWE-bench.

OpenHands — Production Multi-Agent

The most feature-complete open-source agent framework. Event-driven architecture means agents communicate via an event stream, enabling complex orchestration patterns.

Key features: Docker sandboxing (each agent gets isolated container), web UI for monitoring, supports all major LLMs, plugin system for custom tools.

Limitation: Can be heavyweight — more agents than you might want. Best for teams that need production-grade safety rails.

Plandex — Plan-First Development

Terminal-native tool that enforces a plan-first approach. Creates a protected sandbox, generates a plan, lets you review diffs before applying.

Plan
Decompose task into steps
Build in Sandbox
Execute changes in isolation
Review Diffs
Human approves before apply

Simple, focused, 2-agent pattern. Good for when you want control over what gets applied.

Roo Code — Multi-Mode Agent

Cline fork that implements multiple agent "modes" — each mode has a different system prompt and tool access. Think of it as preconfigured agent personas:

Code mode: Full coding agent with file access. Architect mode: Planning only, no file edits. Ask mode: Q&A about codebase. Debug mode: Focused debugging agent.

You can create custom modes — essentially building your own focused agents within the VS Code environment.

5. Claude-Native Agent Ecosystem

Claude Code Built-in Sub-Agents

Claude Code already has a native Agent tool that spawns sub-agents. Each sub-agent can have:

• A different model (Opus for orchestration, Sonnet for workers, Haiku for quick tasks)
• Isolated git worktree (agent works on its own copy of the repo)
• Specific tool restrictions
• Custom prompts defining its role

This is the zero-setup way to implement orchestrator-workers: just spawn multiple sub-agents in parallel from your main Claude Code session.

.claude/agents Directory

You can define custom agent personas in your project's .claude/agents/ directory as YAML files. Each agent gets:

• Custom system prompt (its role and expertise)
• Restricted tool access (e.g., QA agent can only read files, not edit)
• Model preference (e.g., always use Opus for the architect agent)
• Custom CLAUDE.md context

This lets you build Kahler-style focused agents (SEED, PAUL, CARL, Bayes) directly within Claude Code.

Key Resources

Official:

Building Effective Agents — Anthropic's foundational guide
Multi-Agent Research System — Anthropic's own implementation
anthropic-cookbook/patterns/agents — Jupyter notebooks with implementations
Claude Agent SDK docs — Python & TypeScript SDKs

Community:

awesome-claude-code-subagents — 100+ pre-built sub-agent configs
Claude Code Agent Teams Guide — Addy Osmani's walkthrough

6. Recommendations for Vlad

TL;DR: Start with Claude Code's built-in sub-agents + Aider's architect pattern. Add Kahler-style .claude/agents configs for your specific Web3 workflows.

For Pattern A (Orchestrator-Workers / Research → Synthesis)

Best option: Claude Code's native Agent tool — you're already using it. Spawn 3–4 Sonnet sub-agents for parallel research, synthesize with Opus in the main thread. Zero additional setup.

Alternative: Aider's architect mode for code-heavy work — Opus plans, Sonnet edits. Battle-tested, git-aware.

For custom pipelines: Claude Agent SDK (Python) gives you programmatic control to build exactly the orchestration pattern you want.

For Pattern B (PM → Developer → QA → PM)

Best option: Build this in Claude Code using .claude/agents:

pm-agent.yml
Opus — specs & finalizes
dev-agent.yml
Sonnet — implements
qa-agent.yml
Sonnet — reviews from scratch
pm-agent.yml
Opus — accepts/rejects

Alternative: Roo Code's custom modes let you switch between PM/Developer/QA personas within VS Code.

What to Skip

Skip OpenHands unless you need Docker sandboxing — it's powerful but heavy for your use case.
Skip Devin/Codex/Jules — closed commercial products, can't customize agent patterns.
Skip frameworks with 50+ agents — CrewAI, AutoGen, etc. Overkill for focused work.

Recommended Stack

LayerToolWhy
Orchestration Claude Code (built-in Agent tool) Already in your workflow. Sub-agents, model selection, worktree isolation.
Pair Programming Aider (architect mode) Opus plans + Sonnet edits. Git-aware. Terminal-native.
Custom Agents .claude/agents/ YAML configs Define PM, Developer, QA, Research personas per project.
Custom Pipelines Claude Agent SDK (Python) When you need programmatic control beyond what Claude Code provides.
IDE Integration Roo Code (if VS Code) or Continue.dev Multi-mode agents inside your editor.
Research compiled March 31, 2026. Star counts are approximate. URLs verified at time of research — some community repos may move.