LightNow MCP Proxy
Connect your AI clients to your MCP servers—securely managed in one place.
The LightNow MCP Proxy is the local runtime behind LightNow profiles.
Connect Codex, Claude Desktop, Cursor, VS Code, or Antigravity once, then manage
the MCP servers available to that client in LightNow instead of copying server
configuration and secrets into every tool.
- Keep MCP access organized in personal and organization profiles.
- Connect local
stdio and remote Streamable HTTP servers through one entry.
- Resolve credentials on the user's machine instead of embedding them in MCP
client configuration.
- Apply profile and policy changes without rebuilding every client setup.
- Observe client, profile, server health, and tool usage. Tool arguments are
captured by default with credential-like fields redacted and can be disabled;
tool results and resolved secrets are never collected.
The installed command remains lightnow-proxy. It runs locally, uses the
identity-bound LightNow CLI session, resolves the selected profile, and routes
tool and resource requests to the profile's MCP servers.
Capabilities come from your LightNow profile
The proxy deliberately does not ship demo tools. Its MCP capabilities are
the real tools and resources exposed by the servers selected in the active
LightNow profile, so the list differs between teams and clients. Names such as
github__create_issue identify both the upstream server and its tool and avoid
collisions when several servers use the same tool name.
The proxy supports the official MCP 2026-07-28 revision with stateless,
per-request protocol metadata and server/discover. It keeps automatic
compatibility with handshake-era servers and clients through 2025-11-25.
Install
Requirements:
pipx install lightnow-cli
lightnow login
Install the proxy with Homebrew:
brew tap lightnow-ai/tap
brew install lightnow-proxy
Or install it with pipx:
pipx install lightnow-proxy
Or install it with uv:
uv tool install lightnow-proxy
The Python package installs the lightnow-proxy command used by MCP clients.
For repository-local development:
uv tool install --from . lightnow-proxy
Update supported CLI and Proxy installations through the LightNow CLI:
lightnow update --check
lightnow update
Homebrew, pipx and uv are managed. The proxy only reports its observed version
and update state in metadata-only heartbeats; it never invokes a package manager
or delays MCP startup to check for releases.
Use the LightNow CLI. It writes the client MCP entry and the per-client Local
Proxy config.
lightnow sync --client codex --local-proxy
lightnow sync --client claude-desktop --local-proxy
lightnow sync --client cursor --local-proxy
lightnow sync --client vscode --local-proxy
lightnow sync --client antigravity --local-proxy
Restart the MCP client after syncing.
Multiple accounts and organizations
Use a distinct --connection alias for every account, organization or profile
that should appear in the same MCP client:
lightnow login
lightnow sync --client codex --local-proxy \
--connection lightnow-personal --profile default
lightnow login
lightnow sync --client codex --local-proxy \
--connection lightnow-acme --tenant <tenant-id> --profile engineering
Each generated proxy config has a stable connection ID and points to one named
CLI session under ~/.lightnow/sessions/. It also records the expected issuer
and subject. The proxy refuses Registry requests when those values do not
match, so a later CLI login cannot silently switch an existing connection. No
access or refresh token is written to the proxy YAML.
Check the local setup:
lightnow config-status --client codex
Check whether the proxy can resolve the selected profile and reach its upstream
MCP servers:
lightnow-proxy --health
lightnow-proxy --health --json
By default this reads ~/.lightnow/lightnow-proxy/default.yaml, which is written
when the default profile is synced into Local Proxy mode. For a client-specific
config, pass the generated path explicitly:
lightnow-proxy --config ~/.lightnow/lightnow-proxy/codex.yaml --health
lightnow-proxy --config ~/.lightnow/lightnow-proxy/codex.yaml --health --json
Named connections use separate files such as
~/.lightnow/lightnow-proxy/codex-lightnow-acme.yaml. The JSON health report
shows their non-secret connection alias, ID, account label, scope, profile and
identity-binding status. Legacy configs that use cli_config_path remain
readable, but are restricted to the configured authentication issuer.
When telemetry is enabled, active health checks and runtime events are sent to
the LightNow Control Plane. Tool-call arguments are captured by default and can
be disabled independently in the Local Proxy settings. Credential-like fields
are redacted before transmission. The proxy also sends device
presence immediately at startup and every two minutes. The Control Plane can
then show which devices, clients and profiles are active, healthy, degraded, or
failing, along with CLI/Proxy versions and update status. Tool results, resolved
LightNow secrets, unredacted authorization values, network addresses, hardware
identifiers and local paths are not stored. Credential-like argument fields,
including authorization headers, are replaced with [REDACTED] before transmission.
Vault providers configured for runtime resolution are resolved on this host,
after Registry API has returned a provider reference without credentials or a
secret value. HashiCorp Vault Proxy auto-auth on 127.0.0.1:8200 is the
default. Provider-specific loopback listeners can be mapped under
runtime_secrets.providers in the generated YAML; LightNow CLI preserves these
non-secret mappings on subsequent syncs. The optional OS-keyring path is
available with lightnow-proxy[keyring]. Resolution failures are fail-closed
and plaintext values are never added to the tool-schema cache.
Managed runtime files
STDIO servers may attach bounded, non-secret runtime_files to their Runtime
Profile client configuration. LightNow Proxy writes each file set below
~/.lightnow/runtime-files in an immutable content-addressed directory before
the upstream process starts. Files use mode 0600; managed directories use
mode 0700.
Reference the resolved directory with ${LIGHTNOW_RUNTIME_DIR} in arguments,
environment values, or the working directory:
{
"transport": "stdio",
"command": "npx",
"args": [
"@bytebase/dbhub@latest",
"--config",
"${LIGHTNOW_RUNTIME_DIR}/dbhub.toml"
],
"env": {
"DBHUB_DSN": "${DBHUB_DSN}"
},
"runtime_files": [
{
"path": "dbhub.toml",
"content": "[[sources]]\nid = \"analytics\"\ndsn = \"${DBHUB_DSN}\"\n"
}
]
}
Runtime files are UTF-8 text and are limited to 16 files, 64 KiB per file, and
256 KiB per server configuration. Paths must be relative and cannot contain
traversal segments or backslashes. Secret values must remain in LightNow's
runtime secret buckets; files may refer to the corresponding environment names
but must not embed plaintext credentials. Invalid or modified materializations
fail closed before the upstream starts.
More Documentation
Detailed setup guides, examples, diagrams, supported client paths, telemetry
behavior and troubleshooting live in the LightNow docs:
Local Development
For contributors working on this repository:
uv venv
uv pip install -e .[dev]
make test
Jenkins builds the runtime image, runs the Ruff and pytest commands from
make lint test inside it, then checks lightnow-proxy --help.
The checkout is mounted read-only and test environments live in the container.
The Jenkinsfile uses the native
build-agent capability pool and removes only its own validation image. The timeout includes agent allocation.
GitHub Actions continues to run the Python version matrix. Before merging an
Ops dependency update, require terminal Jenkins success at the current PR head.
The pipeline validates changes without publishing an image or changing accounts.
Run the proxy with the example config:
uv run lightnow-proxy --config config.example.yaml
Run the proxy as a stdio MCP server:
uv run lightnow-proxy --config config.example.yaml --transport stdio
Run a local health check against the example config:
uv run lightnow-proxy --config config.example.yaml --health