swarm-code

swarm-code

Open-source swarm-native coding agent orchestrator. Spawns parallel coding agents in isolated git worktrees, orchestrated by a Recursive Language Model (based on arXiv:2512.24601).

Install

npm install -g swarm-code

Requires Node.js >= 20 and Python 3.

Supported Providers

Provider	Env Variable	Default Model
Anthropic	ANTHROPIC_API_KEY	claude-sonnet-4-6
OpenAI	OPENAI_API_KEY	gpt-4o
Google	GEMINI_API_KEY	gemini-2.5-flash

export ANTHROPIC_API_KEY=sk-ant-...

From Source

git clone https://github.com/kingjulio8238/swarm-code.git
cd swarm-code
npm install
npm run build
npm link

Usage

Swarm Mode — Parallel Coding Agents

Point swarm at a repo with a task. It scans the codebase, decomposes the work, and spawns coding agents in isolated git worktrees:

swarm --dir ./my-project "add error handling to all API routes"

The orchestrator LLM writes Python code that calls thread() to spawn agents, asyncio.gather() for parallelism, and merge_threads() to integrate changes:

# With auto model routing (picks best agent+model per task)
swarm --dir ./project --auto-route "migrate from Express to Fastify"

# Dry run — plan without executing
swarm --dir ./project --dry-run "refactor auth module"

# Budget cap
swarm --dir ./project --max-budget 5.00 "add comprehensive tests"

# Specific agent backend
swarm --dir ./project --agent claude-code "review and fix security issues"

# Verbose — see routing decisions and memory hints
swarm --dir ./project --verbose --auto-route "optimize database queries"

Agent Backends

Agent	Description	Best for
opencode (default)	Open-source, multi-provider, tool-capable	General coding, testing
claude-code	Anthropic's Claude Code CLI	Deep analysis, refactoring
codex	OpenAI's Codex CLI	Shell commands, OpenAI models
aider	Git-aware AI coding assistant	Targeted edits, minimal changes
direct-llm	Bare LLM call, no agent wrapper	Analysis, planning, classification

RLM Text Mode (inherited)

The original RLM text-processing mode is preserved:

swarm run --file large-document.txt "summarize the key findings"
swarm run --url https://example.com/data.txt "extract all dates"
cat data.txt | swarm run --stdin "count the errors"

Interactive Mode

Run with --dir but no task to enter interactive mode — a persistent REPL with live thread monitoring:

swarm --dir ./my-project

Commands:

Command	Description
/threads	List all threads with status, cost, duration
/thread <id>	Show thread detail (files changed, diff, result)
/merge	Merge all completed thread branches
/reject <id>	Reject a thread's changes
/dag	Show thread DAG with timing bars
/budget	Show budget breakdown
/status	Show session stats
/help	List commands
/quit	Cleanup and exit

Ctrl+C once cancels the current task. Ctrl+C twice exits.

GitHub Action

Trigger swarm from issue comments. Add .github/workflows/swarm.yml to your repo (a template is provided in this repo):

name: Swarm Agent
on:
  issue_comment:
    types: [created]
  workflow_dispatch:
    inputs:
      task:
        description: 'Task for swarm to execute'
        required: true
        type: string

jobs:
  swarm:
    runs-on: ubuntu-latest
    timeout-minutes: 30
    if: >
      github.event_name == 'workflow_dispatch' ||
      (github.event_name == 'issue_comment' &&
       contains(github.event.comment.body, '@swarm'))
    permissions:
      contents: write
      pull-requests: write
      issues: write
    steps:
      - uses: actions/checkout@v4
      - uses: kingjulio8238/swarm-code@main
        with:
          task: ${{ github.event.inputs.task || '' }}
          anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}
          max_budget: '5.00'

Then comment on any issue:

@swarm fix the auth bug in src/auth.ts

Swarm runs, creates a PR with the changes, and posts a summary back on the issue.

Security: Only OWNER/MEMBER/COLLABORATOR can trigger. Fork PRs are rejected. Budget hard cap of $50. API keys are masked in logs.

Action inputs: task, anthropic_api_key, openai_api_key, gemini_api_key, agent, model, max_budget

Action outputs: success, pr_url, cost_usd, threads_completed, threads_failed, elapsed_s, answer, skipped, skip_reason

MCP Server

Expose swarm as tools for Claude Code, Cursor, or any MCP-compatible agent:

swarm mcp                       # Start MCP server (stdio)
swarm mcp --dir ./my-project    # Start with default directory

Tools exposed:

Tool	Description
swarm_run	Full swarm orchestration — decompose, spawn threads, merge, return result
swarm_thread	Spawn a single coding agent in an isolated worktree
swarm_status	Get session status — threads, budget, costs
swarm_merge	Merge completed thread branches back to main
swarm_cancel	Cancel running thread(s)
swarm_cleanup	Destroy session and clean up worktrees

Claude Code setup:

claude mcp add swarm-code -- npx swarm-code mcp

Or add to your project's .mcp.json:

{
  "mcpServers": {
    "swarm-code": {
      "command": "npx",
      "args": ["swarm-code", "mcp", "--dir", "."],
      "env": {
        "ANTHROPIC_API_KEY": "${ANTHROPIC_API_KEY}"
      }
    }
  }
}

Cursor setup: Add to .cursor/mcp.json with the same format.

Once configured, Claude Code or Cursor can call swarm_thread to spawn coding agents in worktrees, check progress with swarm_status, and merge with swarm_merge — giving the host agent full orchestration control.

Trajectory Viewer

swarm viewer

Browse saved runs in a TUI. View iterations, code, output, sub-queries, and swarm thread DAGs with timing bars and cost breakdowns. Arrow keys to navigate, Enter to drill down into thread details.

Benchmarks

swarm benchmark oolong          # Oolong Synth long-context benchmark
swarm benchmark longbench       # LongBench NarrativeQA benchmark

How It Works

• Scan: Codebase is scanned and loaded as context
• Orchestrate: The RLM loop runs — the LLM writes Python code using swarm primitives
• Decompose: Tasks are broken into independent, parallelizable units
• Spawn: thread() / async_thread() spawn coding agents in isolated git worktrees
• Compress: Agent output is filtered to successful operations only (episode quality)
• Merge: merge_threads() integrates worktree branches back to main
• Verify: Optional test thread validates the merged result

Python Primitives

# Lightweight LLM query (no file changes)
analysis = llm_query(context[:5000], "List all API endpoints")

# Spawn a coding agent in an isolated worktree
result = thread("Fix the auth bug", files=["src/auth.ts"])

# Parallel threads
import asyncio
results = await asyncio.gather(
    async_thread("Add validation to POST /users", files=["src/routes/users.ts"]),
    async_thread("Add validation to POST /orders", files=["src/routes/orders.ts"]),
)

# Merge all thread branches back to main
merge_threads()

# Return final answer
FINAL("Added input validation to all API routes")

Thread DAG Composition

Thread results compose naturally via Python variable persistence:

# Stage 1: Research in parallel
analysis, test_gaps = await asyncio.gather(
    async_thread("Analyze the auth module", files=["src/auth/"]),
    async_thread("Find files with <50% coverage", files=["package.json"]),
)

# Stage 2: Act on Stage 1 results
await asyncio.gather(
    async_thread("Add rate limiting", context=analysis, files=["src/auth/middleware.ts"]),
    async_thread("Add tests for low-coverage files", context=test_gaps),
)

# Stage 3: Merge and validate
merge_threads()
thread("Run full test suite and fix failures")

Configuration

Create swarm_config.yaml in your project root:

# Concurrency
max_threads: 5                    # Max concurrent threads
max_total_threads: 20             # Max threads per session
thread_timeout_ms: 300000         # 5min per thread

# Budget
max_thread_budget_usd: 1.00      # Per-thread cost cap
max_session_budget_usd: 10.00    # Total session cost cap

# Agent
default_agent: opencode           # opencode, claude-code, codex, aider, direct-llm
default_model: anthropic/claude-sonnet-4-6
auto_model_selection: false       # Enable auto-routing

# Compression
compression_strategy: structured  # structured, diff-only, truncate, llm-summary

# Model slots — override model per task type
# model_slot_execution: anthropic/claude-sonnet-4-6
# model_slot_search: anthropic/claude-haiku-4-5
# model_slot_reasoning: anthropic/claude-opus-4-6
# model_slot_planning: anthropic/claude-opus-4-6

# Episodic memory — cross-session strategy learning
episodic_memory_enabled: false
memory_dir: ~/.swarm/memory

# Thread cache persistence
thread_cache_persist: false
thread_cache_dir: ~/.swarm/cache
thread_cache_ttl_hours: 24

Key Optimizations

• Episode quality: Compression filters agent output to only successful operations — failed attempts, stack traces, and retries are stripped automatically
• Subthread caching: Identical threads (same task + files + agent + model) are cached in-memory with optional disk persistence and TTL expiry
• Named model slots: Tasks auto-classified into execution/search/reasoning/planning slots, each with preferred agents and optional model overrides
• Episodic memory: Persists successful thread strategies to disk; trigram-based similarity recall informs agent/model selection in future sessions
• DAG composition: Thread results compose via Python variable persistence (T1+T2 → T3); orchestrator prompt teaches multi-stage pipelines and failure re-routing
• Failure tracking: Exponential-decay weighted failure rates per agent/model pair — recent failures penalized more, agents that keep failing get routed around

Architecture

src/
├── main.ts                    CLI entry point (swarm/run/viewer/benchmark)
├── swarm.ts                   Swarm orchestration (single-shot)
├── interactive-swarm.ts       Interactive REPL with live monitoring
├── cli.ts                     RLM text mode
├── core/
│   ├── rlm.ts                 Core RLM loop (Algorithm 1)
│   ├── repl.ts                Python REPL bridge (JSON over stdin/stdout)
│   ├── runtime.py             Python runtime (thread/async_thread/merge)
│   └── types.ts               Shared type definitions
├── agents/
│   ├── provider.ts            AgentProvider interface + registry
│   ├── opencode.ts            OpenCode (subprocess + server mode)
│   ├── claude-code.ts         Claude Code CLI backend
│   ├── codex.ts               Codex CLI backend
│   ├── aider.ts               Aider backend
│   └── direct-llm.ts          Bare LLM calls
├── threads/
│   ├── manager.ts             Thread lifecycle + concurrency + episodes
│   └── cache.ts               Subthread cache (memory + disk)
├── worktree/
│   ├── manager.ts             Git worktree CRUD
│   └── merge.ts               Branch merging
├── compression/
│   └── compressor.ts          Result compression strategies
├── routing/
│   └── model-router.ts        Auto model/agent selection + failure tracking
├── memory/
│   └── episodic.ts            Cross-session strategy learning
├── prompts/
│   └── orchestrator.ts        Swarm system prompt
├── mcp/
│   ├── server.ts              MCP server entry point (stdio transport)
│   ├── tools.ts               Tool definitions + handlers
│   └── session.ts             Per-directory session state
├── ui/
│   ├── onboarding.ts          First-run setup wizard
│   ├── spinner.ts             CLI spinner
│   ├── dashboard.ts           Live progress dashboard
│   └── summary.ts             Session summary + JSON output
└── viewer.ts                  Trajectory TUI + DAG viewer
action/
├── entrypoint.ts              GitHub Action orchestration
├── parse-trigger.ts           @swarm comment parsing
├── security.ts                Auth + fork detection + budget caps
└── pr.ts                      PR creation + issue commenting

Development

npm install                    # Install deps
npx tsx src/main.ts --dir .    # Run in dev mode
npm run build                  # Compile TypeScript
npm test                       # Run tests

License

MIT