Universal Coder Bridge

A production-oriented MCP + HTTP control plane for routing work to multiple coding-agent CLIs through one normalized contract.

ChatGPT / Codex / Claude / MCP client / private control UI
                         │
             Streamable HTTP MCP :8787
                         │
              Universal Coder Bridge
                         │
      Hermes → OpenCode → Kilo → [optional AGY] → Hermes
       plan     implement   review       finish      synthesize
                         │
                 /opt/data/workspace

The bridge keeps each CLI's native configured model by default. A caller can override a model for one run without rewriting the CLI's persistent configuration.

What is included

• Stateful MCP Streamable HTTP endpoint at /mcp
• Local MCP stdio mode
• Authenticated REST API and run-event SSE
• Normalized adapters for Hermes, OpenCode, Kilo Code, AGY, Codex CLI, Claude Code, and Gemini CLI
• Default pipeline: plan → implement → independent review → bounded revision → optional finish → final synthesis
• Per-agent and global concurrency limits
• Timeouts, cancellation, process-group termination, heartbeats, output tails, and durable artifacts
• Restart recovery for interrupted runs
• Workspace traversal and symlink-escape protection
• Host-header validation and secret redaction
• Docker, systemd, and Caddy deployment files

Telegram is deliberately not part of this build.

Adapter status

All commands are configured in config/agents.json; the bridge does not invoke an arbitrary shell.

MCP tools

agent_continue grounds a new task in the previous run and current repository state. It does not promise native session resumption inside every third-party CLI.

HTTP endpoints

• GET /health — unauthenticated liveness check
• GET /api/agents — adapter configuration and live health
• GET /api/runs?limit=25 — recent runs
• POST /api/runs — submit an agent or pipeline run
• GET /api/runs/:id — inspect one run
• POST /api/runs/:id/continue — submit a follow-up run
• DELETE /api/runs/:id — cancel one run
• GET /api/runs/:id/events — Server-Sent Events stream
• POST|GET|DELETE /mcp — MCP Streamable HTTP transport

Runtime defaults

Port:             8787
HTTP bind:        127.0.0.1
Workspace root:   /opt/data/workspace
Artifact root:    /opt/data/artifacts
Log file:         /opt/data/logs/bridge.log
Global run slots: 2
Model behavior:   native unless explicitly overridden

Install on Ubuntu VPS

Use Node.js 20 or newer.

sudo mkdir -p /opt/universal-coder-bridge
sudo chown "$USER":"$USER" /opt/universal-coder-bridge
cd /opt/universal-coder-bridge

# Copy or extract this project here.
npm install --no-audit --no-fund
npm run check
npm run verify:runtime

cp .env.example .env
cp config/agents.example.json config/agents.json

Generate a service token:

openssl rand -hex 32

Place it in .env as BRIDGE_AUTH_TOKEN. Keep the bridge on 127.0.0.1 when Caddy is the public HTTPS entry point.

Each enabled coder must be installed and authenticated for the same Linux user that runs the bridge:

hermes --version
opencode --version
kilo --version

Enable only the adapters whose command syntax you have verified locally.

Start directly:

npm run build
npm start
curl http://127.0.0.1:8787/health

Systemd deployment

Create a dedicated unprivileged user and runtime directories:

sudo useradd --system --create-home --shell /usr/sbin/nologin sorenbridge
sudo mkdir -p /opt/data/{workspace,artifacts,logs}
sudo chown -R sorenbridge:sorenbridge /opt/data
sudo chown -R sorenbridge:sorenbridge /opt/universal-coder-bridge

Install the environment and unit:

sudo cp .env.example /etc/universal-coder-bridge.env
sudo chmod 600 /etc/universal-coder-bridge.env
sudo cp deploy/systemd/universal-coder-bridge.service /etc/systemd/system/
sudo systemctl daemon-reload
sudo systemctl enable --now universal-coder-bridge
sudo systemctl status universal-coder-bridge
journalctl -u universal-coder-bridge -f

The service unit sets HOME=/home/sorenbridge because agent CLIs commonly keep authentication and writable caches under the service user's home. Install and authenticate each CLI as sorenbridge; do not run the bridge as root.

Caddy and allowed hosts

Copy deploy/caddy/Caddyfile.example, replace bridge.example.com, and keep streaming enabled.

The public hostname must also appear in ALLOWED_HOSTS:

ALLOWED_HOSTS=localhost,127.0.0.1,[::1],bridge.example.com

Remote MCP client

{
  "mcpServers": {
    "universal-coders": {
      "url": "https://bridge.example.com/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_BRIDGE_TOKEN"
      }
    }
  }
}

A static bearer token is appropriate for a private, service-to-service bridge. Put a standards-compliant OAuth or identity-aware gateway in front before exposing it as a public multi-user service.

Run one coder

curl -X POST http://127.0.0.1:8787/api/runs \
  -H "Authorization: Bearer $BRIDGE_AUTH_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "agentId": "opencode",
    "task": "Inspect the project, run tests, and fix the failing test.",
    "workspace": "my-project",
    "model": {"mode": "native"}
  }'

One-run model override:

{
  "agentId": "opencode",
  "task": "Implement the feature and verify it.",
  "workspace": "my-project",
  "model": {"mode": "override", "value": "provider/model"}
}

Run the universal pipeline

curl -X POST http://127.0.0.1:8787/api/runs \
  -H "Authorization: Bearer $BRIDGE_AUTH_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "kind": "pipeline",
    "task": "Add authenticated project sharing and verify it end to end.",
    "workspace": "my-project",
    "plannerId": "hermes",
    "implementerId": "opencode",
    "reviewerId": "kilo",
    "finalizerId": "hermes",
    "maxRevisions": 1
  }'

To include a verified finisher adapter, add "finisherId": "agy" after enabling AGY.

Continue a completed run

curl -X POST http://127.0.0.1:8787/api/runs/RUN_ID/continue \
  -H "Authorization: Bearer $BRIDGE_AUTH_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"instruction":"Run the full regression suite and fix anything related."}'

Add another coding CLI

Add an object to config/agents.json:

{
  "id": "new-coder",
  "displayName": "New Coder",
  "description": "What it is responsible for.",
  "role": "implementer",
  "enabled": true,
  "command": "new-coder",
  "args": ["run", "{{prompt}}"],
  "inputMode": "argument",
  "modelArgs": ["--model", "{{model}}"],
  "modelArgsIndex": 1,
  "env": {},
  "capabilities": ["implement", "test"],
  "timeoutSeconds": 1200,
  "maxConcurrency": 1,
  "versionArgs": ["--version"]
}

Templates supported in args: {{prompt}}, {{workspace}}, and {{runId}}. {{model}} is supported in modelArgs.

modelArgsIndex is a zero-based insertion position in the base args array. Set it so model flags never split a flag from the value it consumes. Examples:

Hermes:      [chat, --model, MODEL, -q, PROMPT]       index 1
OpenCode:    [run, --model, MODEL, PROMPT]            index 1
Kilo:        [run, --auto, --model, MODEL, PROMPT]    index 2
Claude:      [--model, MODEL, -p, PROMPT, ...]        index 0

For CLIs that read the task from stdin, use "inputMode": "stdin"; the configured argument list remains shell-free.

Security boundaries

• Only configured executables and argument arrays are spawned; there is no arbitrary root_shell tool.
• Workspaces must remain under WORKSPACE_ROOT, including after symlink resolution.
• HTTP binding to a non-loopback address without BRIDGE_AUTH_TOKEN is rejected at startup.
• Host headers are checked against ALLOWED_HOSTS.
• Authorization tokens are redacted from structured logs.
• Runs have bounded timeouts, cancellation, output capture limits, heartbeats, and process-group termination.
• run.json, stdout.log, and stderr.log are persisted under the artifact root.
• Runs left active by an unexpected restart are recovered as failed instead of remaining permanently “running.”
• Stdio mode writes bridge logs to stderr so MCP protocol messages on stdout remain clean.

The coding CLIs can still edit files and execute commands according to their own permissions. Keep .env, SSH keys, API keys, deployment credentials, and unrelated repositories outside WORKSPACE_ROOT. For hostile or untrusted workloads, add a stronger per-run container, VM, or sandbox boundary.

Docker

cp .env.example .env
docker compose up --build -d

Compose overrides the container bind address to 0.0.0.0, while publishing the host port only on 127.0.0.1:8787.

The base image contains the bridge, not the coding CLIs. Extend the image with only the adapters you need, or use systemd so the bridge can reach host-installed CLIs and their user-scoped credentials.

Local stdio mode

BRIDGE_TRANSPORT=stdio npm start

Development and verification

npm install --no-audit --no-fund
npm run typecheck
npm test
npm run verify:runtime
npm run build

See VERIFICATION.md for the checks completed when this package was generated and the remaining environment-dependent verification steps.