Skip to main content
Glama
Sign In
deenesjakoruzh
nexus-mcp

nexus-mcp

by j7an
OverviewSchemaSourceRelated ServersDiscussionsAdmin
Python
Local

nexus-mcp

MCP server that delegates tasks to coding agents — Claude Code via the Claude Agent SDK, Codex via the Codex App Server, and Antigravity via the Antigravity SDK — from any MCP client.

Install

Backends are optional extras; install the ones you use.

Extra

Backend

Adds

claude

Claude Agent SDK

claude-agent-sdk (bundles the Claude Code CLI, ~100 MB)

codex

Codex App Server

openai-codex (bundles the Codex CLI, ~120–150 MB)

antigravity

Antigravity SDK

google-antigravity (bundles the Antigravity Go harness, ~40 MB)

all

every backend

uvx --with 'nexus-mcp[all]' nexus-mcp          # run directly
pip install 'nexus-mcp[claude]'                 # or install
pip install 'nexus-mcp[codex]'                  # Codex only
pip install 'nexus-mcp[antigravity]'

Claude Code MCP config:

{ "mcpServers": { "nexus": { "command": "uvx", "args": ["--with", "nexus-mcp[all]", "nexus-mcp"] } } }

Authentication is the agent's own: log in with claude, or set ANTHROPIC_API_KEY; for Codex, log in with codex login (credentials in ~/.codex are shared). Antigravity uses GEMINI_API_KEY, or Vertex AI with GOOGLE_GENAI_USE_VERTEXAI, GOOGLE_CLOUD_PROJECT, and GOOGLE_CLOUD_LOCATION, authenticated through Application Default Credentials (ADC). It does not use Google-account login.

Windows: recent claude-agent-sdk releases ship no Windows wheel with a bundled CLI; install Claude Code so claude is on PATH.

Related MCP server: wrapmcp

Tool: prompt

Runs one agent turn and returns its final answer.

Parameter

Default

Meaning

backend

required

claude, codex, or antigravity

prompt

required

Task for the agent

cwd

required

Absolute project directory

profile

read_only

Permission profile (below)

session_id

—

Continue this conversation

fork

false

Branch session_id into a new conversation

model

provider default

Model id or alias

timeout

600

Seconds before the turn is cancelled

Returns {backend, session_id, output, usage}. Conversations are stored by the agent itself (~/.claude/projects, $CODEX_HOME/sessions, ~/.nexus-mcp/antigravity), so a session_id keeps working after nexus-mcp restarts. Antigravity does not support fork=true.

Permission profiles

Actions outside the chosen profile are denied automatically — nobody is prompted.

Profile

Allows

read_only

Read/Glob/Grep; git diff/log/show with --no-ext-diff --no-textconv

workspace_write

Plus file edits inside cwd and Bash inside the OS sandbox

full_access

Everything

Codex enforces profiles with its OS sandbox (read-only, workspace-write, danger-full-access) and never asks for approval.

Antigravity enforces workspace containment in its harness and uses the OS sandbox for commands. workspace_write fails if that sandbox is unavailable.

Resource: nexus://backends

JSON list of {name, installed, models, hint}; hint gives the install command for a missing extra. Codex lists its models; Claude and Antigravity report null (Antigravity does not provide a model list).

Configuration

Variable

Default

Meaning

NEXUS_CLAUDE_SETTINGS_PROFILE

isolated

Claude settings to load: isolated (none), project (project .claude/), inherit (all, including user settings). Profiles still bound every tool call.

Migrating from v1

v1

v2

prompt(cli="codex") (codex exec)

prompt(backend="codex", cwd=…) (App Server)

prompt(cli=…, execution_mode="yolo")

prompt(backend=…, profile="full_access", cwd=…)

batch_prompt

Parallel prompt calls from the client

agent_start / agent_status / agent_result

prompt (synchronous)

agent_continue / agent_fork

prompt(session_id=…) / prompt(session_id=…, fork=true)

agent_review

prompt(profile="read_only", prompt="Review …")

agent_cancel

Cancel the tool call in the client

agent_respond, elicitation

Removed — choose a profile instead

Preferences, model tiers, MCP prompts

Removed

OpenCode runners and tools

Removed

NEXUS_* variables

Removed except NEXUS_CLAUDE_SETTINGS_PROFILE

Development

uv sync --all-extras --all-groups
uv run pytest                    # unit + e2e
uv run pytest -m integration     # real CLI (slow, makes model calls)
uv run mypy src/nexus_mcp && uv run ruff check . && uv run ruff format --check .

License

MIT

Available Tools

1 tool
promptPromptB
Destructive

Run one turn with a coding agent and return its final answer.

Inputs: cwd (required), prompt (required), backend (required), fork, +4 more. Returns: Final answer of one agent turn.

Tool Schema Changelog

Recent tool additions, removals, and schema changes observed during successful MCP inspections.

Loading tool schema changelog…

    Deploy Server
    Claude Code, inside the Godot 4 editorFlockbay puts an AI agent in the real Godot 4 editor: it writes GDScript, runs your game and fixes what breaks. Free, or bring your own Claude Code or Codex.flockbay.comAd

    TDQS

    B3/5.0

    Scored across 1 tool

    Disambiguation4/5

    With only a single tool, there is no possibility of confusing it with another, so misselection is impossible. However, there is no sibling tool to distinguish it from, making the dimension trivially satisfied rather than well-designed.

    Naming Consistency3/5

    There is only one tool named 'prompt', a bare noun rather than a verb_noun pattern. With a single name there is nothing to be inconsistent with, but the naming itself is vague about what the tool does.

    Tool Count2/5

    A single tool is far too thin for a server that wraps a coding agent. Core capabilities like starting a session, sending follow-ups, or checking status are absent, leaving the surface severely under-scoped.

    Completeness2/5

    Only one fire-and-forget turn is exposed, with no session lifecycle, multi-turn conversation, cancellation, or status operations. This leaves significant gaps for any realistic agent-driven coding workflow.

    Maintenance

    ActivityActive
    ResponsivenessNo recent community issues

    Resources

    Related MCP Connectors

    Related MCP Servers