AgentHub

▶ Watch the demo in full quality (MP4, 50 s): a real run, not a mock-up.

Let Claude Code hand work to other coding agents (Codex, Antigravity, Claude, Aider, Goose, or any CLI) without handing them your whole machine.

AgentHub is a small MCP server, CLI and optional HTTP API. Use it to:

• Get a second opinion. Send one question to several agents and compare the answers (compare).
• Get a cross-model review of your diff before you commit (review).
• Delegate safely. An agent works in its own git worktree. You see the diff, then apply or discard it.
• Use the subscriptions you already pay for. ChatGPT through Codex, Google through Antigravity, all from one place, with automatic fallback when one runs out of quota.
• Run long jobs in the background, wait for them, read readable logs.
• Search other agents' past sessions, or continue them.

Every request goes through one policy layer: trusted folders, permission modes, a minimal environment, timeouts, quota tracking and a hash-chained audit log.

Pure Python standard library. No dependencies. Linux and macOS. About 20 MB of RAM.

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Quick start

pipx install agenthub-gateway       # or: uv tool install agenthub-gateway
agenthub config --init               # writes ~/.agenthub/config.json
$EDITOR ~/.agenthub/config.json      # set "trusted_workspaces": ["~/code"]
agenthub doctor

Then connect it to Claude Code in one of two ways:

# A) Plugin: MCP server plus slash commands (/second-opinion, /cross-review, /delegate, /agent-tasks)
claude plugin marketplace add premanand8800/agenthub-mcp
claude plugin install agenthub@agenthub

# B) MCP server only
agenthub install-claude

Restart Claude Code and try:

/cross-review codex

/delegate codex add input validation to the signup handler and run its tests

Use agenthub to compare codex and claude on: what's the safest way to migrate this table?

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How a delegated change works

start_task(isolation="worktree")  →  agent edits a private checkout (your files are untouched)
wait_task                         →  blocks until done; returns final output, session_id, token usage
get_task_diff                     →  file list + patch
review(task_id=…)                 →  optional: another model reviews that patch
apply_task  |  discard_task       →  patch lands in your working tree (uncommitted), or is thrown away

The worktree starts from your current state, including uncommitted changes to tracked files. Build junk (__pycache__, node_modules, …) is left out of the diff. If your files changed in the meantime, apply_task tries a 3-way merge. If that conflicts, it keeps the worktree so you can resolve it by hand.

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Permission modes

Mode	Meaning	Codex	Claude	Antigravity	Aider	Goose
read-only	Inspect only	-s read-only	plan	--mode plan --sandbox	--dry-run	GOOSE_MODE=chat
workspace-write (default)	Edit files in workdir	-s workspace-write	acceptEdits	--mode accept-edits --sandbox	no shell commands	–
full	No sandbox, no approvals	--dangerously-bypass-…	bypassPermissions	--dangerously-skip-permissions	--yes-always	GOOSE_MODE=auto

• full is off until a human sets "allow_full_access": true. A model cannot turn it on.
• review and compare always run read-only.
• If an agent can't enforce a mode, AgentHub refuses the request instead of quietly running with weaker settings.
• A delegated Claude runs with --strict-mcp-config, so it can't use your other MCP servers (email, chat, AgentHub itself).

---

MCP tools

Tool	What it does	Read-only
list_agents	Installed agents, modes, features, quota health	yes
ask	Run a prompt and wait. Returns reply, session_id, usage, cost_usd	no
start_task	Background job, optionally isolation:"worktree"	no
wait_task	Block until a task finishes (up to 10 min per call)	yes
get_task / get_task_logs / list_tasks	Status, final output, readable logs	yes
cancel_task	Kill a task and all its child processes	no
get_task_diff	What a worktree task changed	yes
apply_task / discard_task	Land or drop a worktree task's changes	no
review	Read-only review of git diff <base> or of a task's diff	yes*
compare	Same prompt to 2–5 agents in parallel	yes*
list_sessions / search_sessions / get_transcript	Other agents' history	yes
list_models	Model IDs per agent	yes
send_message	Message a live session	no

* These don't change your files, but they do send code to the agents' vendors and use quota.

Options for ask and start_task: workdir, permission_mode, model, and session_id (continue a conversation). Also:

• add_dirs: extra directories
• images: Codex only
• output_schema: a JSON Schema; the answer comes back parsed in structured
• fallback_agents: other agents to try if this one is out of quota or not installed

Long calls send MCP progress notifications every 10 s when the client asks for them.

To skip permission prompts for tools that only read:

// ~/.claude/settings.json
{ "permissions": { "allow": [
  "mcp__agenthub__list_agents", "mcp__agenthub__wait_task", "mcp__agenthub__get_task",
  "mcp__agenthub__get_task_logs", "mcp__agenthub__list_tasks", "mcp__agenthub__get_task_diff",
  "mcp__agenthub__list_sessions", "mcp__agenthub__search_sessions", "mcp__agenthub__get_transcript",
  "mcp__agenthub__list_models"
] } }

---

Reliability

• Quota-aware. When a provider reports a quota or rate limit, AgentHub records it, including the reset time when the message gives one ("Resets in 137h"). That agent then fails fast with quota_exhausted until the reset time. fallback_agents moves on to the next agent automatically. list_agents shows each agent's health.
• No unsafe retries. An agent run that failed partway may already have edited files, so AgentHub never retries it automatically. Falling back to another agent only happens when nothing ran.
• Survives restarts. Background tasks keep running if Claude Code closes, and their status still works from any process. In-flight ask calls are killed when the client disconnects, so nothing keeps spending.
• Global limits. max_concurrent_tasks holds across every Claude Code session, enforced with a file lock.

---

CLI (also built for agents)

Every command is non-interactive, has --json, and uses stable exit codes. Other agents can call AgentHub from their own terminals.

agenthub agents [--json]
agenthub ask codex "explain main.py" -m read-only [--session ID] [--schema s.json] [--fallback claude]
agenthub run codex "add tests" --isolation worktree      → prints task ID
agenthub wait ID [--timeout 600]      exit 0 succeeded · 1 failed · 3 still running
agenthub diff ID | apply ID | discard ID
agenthub review codex [--base main | --task ID]
agenthub compare codex,claude "which approach is safer?"
agenthub tasks | task ID | logs ID | cancel ID
agenthub audit [--verify] · config [--init] · token [--rotate] · serve · doctor
agenthub approve antigravity "Bash(npm test)"     human-only

Exit codes: 0 ok · 1 the agent or task failed · 2 usage error · 3 still running (for wait).

---

Configuration

~/.agenthub/config.json. Every key is optional. Unknown keys are an error, so typos don't fail silently. Set AGENTHUB_HOME to move the whole directory.

Key	Default
trusted_workspaces	["~"]	Agents may only run inside these. Narrow this.
denied_paths	~/.ssh, ~/.gnupg, ~/.aws, ~/.config/gcloud, ~/.kube, ~/.agenthub	Always refused
default_permission_mode	workspace-write
allow_full_access	false	Allows full mode
env_passthrough	[]	Extra env vars for agents (globs), e.g. ["GH_TOKEN"]
inherit_env	false	true passes your entire environment (not recommended)
ask_timeout_seconds / task_timeout_seconds	900 / 14400
max_concurrent_tasks	4	Across all sessions
max_prompt_chars / max_output_chars	100000 / 60000
max_delegation_depth	2	Stops agent → hub → agent loops
quota_backoff_seconds	900	How long to skip an agent after a quota error with no reset time
audit_prompt_preview_chars	80	0 logs only prompt length and SHA-256
task_retention_days	7	Old tasks and their worktrees are deleted
http_allowed_origins	[]	Browser origins allowed to call the HTTP API

Environment: agents get only what they need:

• PATH, HOME, locale, proxies, CA bundles
• toolchain variables (nvm, cargo, go, java, venv, …)
• their own API-key variables (OPENAI_* for Codex, ANTHROPIC_* for Claude, …)

Cloud credentials such as AWS_* and GH_TOKEN are not passed unless you list them in env_passthrough.

---

Custom agents

Put a JSON file in ~/.agenthub/agents/ (mode 600). See examples/custom-agent.json.

{
  "name": "myagent",
  "command": "myagent",
  "args": ["run", "--prompt={prompt}"],
  "model_args": ["--model", "{model}"],
  "add_dir_args": ["--add-dir", "{dir}"],
  "output_schema_args": ["--schema", "{schema_file}"],
  "json_output": { "reply": "result", "session_id": "session_id", "cost_usd": "cost" },
  "env_passthrough": ["MYAGENT_API_KEY"],
  "modes": { "read-only": ["--no-write"], "workspace-write": ["--sandbox"] }
}

• modes lists only what your CLI can really enforce.
• json_output tells AgentHub where to find the reply and session ID when your CLI prints JSON.
• Specs that are group- or world-writable are refused, and so are specs that reuse a built-in name. agenthub doctor reports why.

---

HTTP API (optional)

agenthub serve                                   # 127.0.0.1:8765
TOKEN=$(agenthub token)
curl -s localhost:8765/v1/agents/codex/ask -H "Authorization: Bearer $TOKEN" \
     -H 'Content-Type: application/json' -d '{"prompt":"hi","permission_mode":"read-only"}'

Method	Path
GET	/health (no auth) · /v1/agents · /v1/agents/{agent}/models
POST	/v1/agents/{agent}/ask · /v1/agents/{agent}/tasks · /v1/review · /v1/compare
GET	/v1/agents/{agent}/sessions · …/sessions/search?q= · …/sessions/{id}
POST	/v1/agents/{agent}/sessions/{id}/messages
GET	/v1/tasks · /v1/tasks/{id} · /v1/tasks/{id}/wait?timeout= · /v1/tasks/{id}/logs?tail= · /v1/tasks/{id}/diff
POST	/v1/tasks/{id}/cancel · /v1/tasks/{id}/apply · /v1/tasks/{id}/discard

Errors are always {"ok": false, "error": {"code", "message"}}. A quota_exhausted error also includes retry_after_seconds.

---

Security model

See SECURITY.md. In short:

• The model is untrusted. Defaults assume a prompt injection will reach AgentHub. Every agent run is sandboxed, limited to trusted folders, given a minimal environment, time-limited and audited. A model can't enable full mode or approve its own tools.
• No shell, ever. Prompts can't become CLI options.
• Private state. All state lives in ~/.agenthub (0700), never in /tmp.
• Tamper-evident audit log. agenthub audit --verify.

Development

git clone https://github.com/premanand8800/agenthub-mcp && cd agenthub-mcp
PYTHONPATH=src python -m unittest discover -s tests -t tests -v

Tests use a fake agent: no API keys, no quota. To add a built-in adapter, subclass agenthub.adapters.base.Adapter, then:

• implement build_command(spec), and parse_output if your CLI prints JSON
• declare modes and env_allow
• register it in adapters/__init__.py

Contributing

Issues and PRs welcome — see CONTRIBUTING.md. Security reports: SECURITY.md.

License

MIT