The full upstream README, mirrored here for reference. Install config, tool schemas, adoption signals, and an original overview live on the Synapse RMCP listing page.
Host, Docker, Compose, SSH, logs, ZFS, and file operations over MCP and CLI.
Synapse is a full-parity Rust port of synapse-mcp, built with the rmcp framework.
The server exposes two MCP tools (flux and scout) plus equivalent CLI
commands, covering all 59 production actions from the original TypeScript server.
The repository is synapse-rmcp, the Rust crate is synapse, the MCP server
identity is synapse, and the installed binary is synapse. The npm launcher
package is synapse-rmcp.
Across most of the RMCP family, naming follows
repo=<service>-rmcp, npm=<service>-rmcp, and CLI=r<service>. Synapse is an
exception because it is a Rust port of the older TypeScript synapse-mcp
project and keeps the operator-facing synapse binary.
Synapse provides local Docker, Compose, host, SSH, log, ZFS, and file-operation workflows through two MCP tools and the equivalent CLI:
flux manages Docker infrastructure, containers, Compose projects, and host
inspection.scout handles SSH/local host inspection, safe file reads, allowlisted
command execution, bounded descriptor-confined file transfer, ZFS introspection,
and log retrieval.Not for: arbitrary shell access, unaudited remote mutation, or bypassing host SSH trust. Destructive Docker/Compose/exec/file-transfer actions require explicit host targets and confirmation policy.
MCP callers never provide credentials, tokens, keys, or secrets as action arguments. Tokens, OAuth settings, host topology, SSH trust, and allowlists live in server-side configuration or the local SSH environment.
Use the npm launcher for stdio MCP or CLI access without a manual binary install:
For a permanent command:
The npm package downloads the synapse binary from GitHub Releases during
postinstall, keeping the release tag aligned with
packages/synapse-rmcp/package.json.
From source:
The production image includes Python 3 plus the official Docker CLI/Compose
plugin because Scout's remote descriptor wrappers and Flux Compose operations
invoke those runtime tools. The image does not contain a Docker daemon; Flux
uses the mounted socket or SSH-forwarded remote socket. Persistent appdata lives
at ~/.synapse on the host and /data in the container.
The first-screen 30-second path is:
Then configure an MCP client with stdio:
Start with a read-only call:
stdio is preferred for local MCP clients:
Streamable HTTP uses /mcp on the configured host and port:
plugins/synapse/ ships Claude Code, Codex, and Gemini CLI manifests that all
point at the same HTTP MCP endpoint and the same shared skill.
These packages contain no lifecycle hooks. Connecting to a server that is
already running needs no setup — the manifests substitute your server_url and
api_token directly. If this machine also runs the server, bootstrap it once
by hand:
Export the relevant SYNAPSE_* variables (or write them to ~/.synapse/.env)
first; plugins/README.md maps each plugin option to its variable. Re-run
synapse setup install after a plugin update.
| Surface | Status | Purpose |
|---|---|---|
| MCP | Required | Agent-facing flux and scout tools |
| CLI | Required | Scriptable parity surface for operators |
| REST | Compatibility | Thin local action endpoint for 14 of 59 actions |
| Web | Present | Lightweight static admin shell |
Synapse exposes two MCP tools:
flux: Docker daemon, container, host, and Compose operations.scout: SSH/local host inspection, filesystem reads, allowlisted exec,
multi-host emit, file beam, ZFS, and logs.Both tools use an action-dispatched JSON shape:
The detailed action tables below are curated README reference material. The generated runtime MCP schema and the Rust action definitions are the source of truth for the live tool contract.
Common commands:
Mounted HTTP supports bearer and Google OAuth modes. Loopback stdio/local dev can run without mounted HTTP auth. Important variables:
See Configuration and docs/CONFIG.md for the full auth
matrix.
Synapse separates read and write scopes (synapse:read, synapse:write) and
uses confirmation gates for destructive operations. SYNAPSE_MCP_ALLOW_DESTRUCTIVE
can skip prompts only in loopback-safe contexts. Host protocol is authoritative
and defaults to SSH when omitted; local execution requires the explicit built-in
local host or protocol: "local". SSH host trust is delegated to OpenSSH
known-hosts behavior, and command execution uses execvp/argv semantics without
shell interpolation. scout beam enforces both endpoints' configured read roots,
blocks sensitive and symlinked paths, and caps each transfer at 64 MiB.
scout exec and scout emit accept only these 18 typed commands
(ALLOWED_READ_COMMANDS in src/synapse/command_policy.rs):
cat, head, tail, grep, rg, ls, tree, wc, uniq, diff, stat,
file, du, df, pwd, hostname, uptime, whoami
git is deliberately excluded, as are shells, interpreters, network clients, and
mutating tools (EXEC_DENYLIST). There is no find or sort in the allowlist —
use the dedicated scout find action for filesystem search. Per-host custom
commands may be enabled via execAllowlist, but receive a zero-argument policy
until a typed argument policy is registered.
The source of truth for release identity is the version shared by Cargo.toml,
.release-please-manifest.json, packages/synapse-rmcp/package.json, release
artifacts, and server.json.
Distribution/version invariants:
synapse.server.json must point at ghcr.io/dinglebear-ai/synapse:<version>.For a persistent mounted HTTP server:
Use bearer or OAuth before exposing the endpoint beyond loopback. Production
Docker/Compose notes live in docs/DEPLOYMENT.md and docs/DOCKER.md when
present; local operator usage can stay on stdio.
401 or 403 from /mcp: check bearer/OAuth settings and gateway headers.SYNAPSE_HOSTS_CONFIG, SYNAPSE_CONFIG_FILE, and
~/.ssh/config.flux — Docker infrastructure managementflux docker — Docker daemon operations (9 actions)| Subaction | Scope | Description |
|---|---|---|
info | synapse:read | Docker daemon information |
df | synapse:read | Docker disk usage |
images | synapse:read | List Docker images; dangling_only to filter untagged |
networks | synapse:read | List Docker networks |
volumes | synapse:read | List Docker volumes |
pull | synapse:write | Pull a Docker image; requires host, image |
build | synapse:write | Build a Docker image; requires host, context, tag; optional dockerfile, no_cache |
rmi | synapse:write | Remove a Docker image; requires host, image, force=true |
prune | synapse:write | Remove unused resources; requires host, prune_target, force=true |
flux container — Container lifecycle + inspection (14 actions)| Subaction | Scope | Description |
|---|---|---|
list | synapse:read | List containers; optional state, name_filter, image_filter, label_filter |
inspect | synapse:read | Detailed container info; requires container_id; optional summary |
logs | synapse:read | Container logs; requires container_id; optional lines, since, until, grep, stream |
stats | synapse:read | Resource usage stats; optional container_id |
top | synapse:read | Show running processes; requires container_id |
search | synapse:read | Full-text search by name/image/labels; requires query |
start | synapse:write | Start a stopped container; requires host, container_id |
stop | synapse:write | Stop a running container (destructive); requires host, container_id |
restart | synapse:write | Restart a container; requires host, container_id |
pause | synapse:write | Pause a running container; requires host, container_id |
resume | synapse:write | Resume a paused container; requires host, container_id |
pull | synapse:write | Pull latest image for a container; requires host, container_id |
recreate | synapse:write | Recreate container with image pull (destructive); requires host, container_id; optional pull (default true) |
exec | synapse:write | Execute command inside container (destructive, execvp); requires host, container_id, command array |
flux host — Host inspection (9 actions)| Subaction | Scope | Description |
|---|---|---|
status | synapse:read | Check Docker connectivity on a host |
info | synapse:read | OS, kernel, architecture |
uptime | synapse:read | System uptime |
resources | synapse:read | CPU, memory, disk usage |
services | synapse:read | Systemd service status; requires host; optional state, service |
network | synapse:read | Network interfaces |
mounts | synapse:read | Mounted filesystems; requires host |
ports | synapse:read | Port mappings; requires host; optional protocol, limit, offset |
doctor | synapse:read | Diagnostic checks; requires host; optional checks (comma-separated) |
flux compose — Docker Compose project management (10 actions)| Subaction | Scope | Description |
|---|---|---|
list | synapse:read | List all Docker Compose projects; requires host |
status | synapse:read | Get project service status; requires host, project; optional service |
up | synapse:write | Start a compose project; requires host, project |
down | synapse:write | Stop a compose project (destructive); requires host, project; optional remove_volumes, force |
restart | synapse:write | Restart a compose project (destructive); requires host, project |
recreate | synapse:write | Recreate compose containers (destructive); requires host, project |
logs | synapse:read | Get project logs; requires host, project; optional service, lines, since |
build | synapse:write | Build compose project images; requires host, project; optional service |
pull | synapse:write | Pull compose project images; requires host, project; optional service |
refresh | synapse:read | Refresh compose project cache; requires host |
flux help — Auto-generated flux docs| Action | Scope | Description |
|---|---|---|
help | public | Return flux action reference; optional topic (e.g. "container:list"), format (markdown|json) |
scout — SSH/local host inspection| Action | Scope | Description |
|---|---|---|
nodes | synapse:read | List all configured SSH hosts |
peek | synapse:read | Read a file or directory listing; requires host, path; optional tree, depth |
find | synapse:read | Find files by glob; requires host, path, pattern; optional depth, limit |
ps | synapse:read | List processes; requires host; optional sort (cpu|mem|pid|time), grep, user, limit |
df | synapse:read | Disk usage; requires host; optional path |
delta | synapse:read | Compare files or content; requires source_host, source_path; then either target_host+target_path or content |
exec | synapse:write | Execute allowlisted command (destructive, execvp); requires host, command; optional path, args, timeout_secs |
emit | synapse:write | Multi-host execution (destructive); requires targets array, command; optional args, timeout_secs |
beam | synapse:write | Bounded root-confined file transfer (destructive); requires source_host, source_path, dest_host, dest_path; both paths must be under configured Scout/Compose roots |
scout zfs — ZFS introspection (3 subactions)| Subaction | Scope | Description |
|---|---|---|
pools | synapse:read | List ZFS pools; requires host; optional pool name filter |
datasets | synapse:read | List ZFS datasets; requires host; optional pool, dataset_type, recursive |
snapshots | synapse:read | List ZFS snapshots; requires host; optional pool, dataset, limit |
scout logs — Log retrieval (4 subactions)| Subaction | Scope | Description |
|---|---|---|
syslog | synapse:read | Read /var/log/syslog (falls back to /var/log/messages); requires host; optional lines, grep |
journal | synapse:read | Read systemd journal; requires host; optional lines, unit, priority, since, until, grep |
dmesg | synapse:read | Read kernel ring buffer; requires host; optional lines, grep |
auth | synapse:read | Read /var/log/auth.log (falls back to /var/log/secure); requires host; optional lines, grep |
scout help — Auto-generated scout docs| Action | Scope | Description |
|---|---|---|
help | public | Return scout action reference; optional topic (e.g. "zfs:pools"), format (markdown|json) |
synapse achieves action-level parity with synapse-mcp — all 59
production actions from synapse-mcp/docs/INVENTORY.md are implemented. However,
the following features from the original TypeScript server are not yet ported:
| Feature | Description |
|---|---|
claude/channel notifications | Original forwards Docker events and log tails as notifications/claude/channel MCP notifications. No equivalent exists in Rust. |
| Templated MCP resources | Original exposes synapse://hosts/{host}, synapse://hosts/{host}/stacks, synapse://stacks, synapse://stacks/{host}/{stack}, synapse://stacks/{host}/{stack}/env, synapse://containers/{host}, synapse://containers/{host}/{id}. Rust exposes tool-specific schema and help resources plus read-scoped synapse://hosts, synapse://compose/projects, synapse://status, and synapse://activity. |
| Root SSH login gate | Original gates sshUser=root through elicitation unless SYNAPSE_ALLOW_ROOT_LOGIN=true. Rust has destructive-operation elicitation but no root-login gate. |
| TOFU fingerprint store | Original persists fingerprints to ~/.config/synapse/known_hosts.json and rejects changed fingerprints. Rust uses strict OpenSSH known_hosts with wildcard warnings — different operator behavior. |
SYNAPSE_EXCLUDE_HOSTS | Original env var to exclude hosts from fleet discovery is absent in Rust. |
SYNAPSE_MCP_ALLOW_YOLO | Original "skip all confirmation gates" mode. Rust has SYNAPSE_MCP_ALLOW_DESTRUCTIVE (per-restart override, loopback-only), which is not identical. |
SYNAPSE_DEBUG_ERRORS | Original opt-in mode that returns full internal error detail. Rust always sanitizes internal tool errors. |
git in exec allowlist | Original includes git in ALLOWED_READ_COMMANDS with flag guards. Rust deliberately excludes git. |
Key environment variables:
| Variable | Default | Description |
|---|---|---|
SYNAPSE_MCP_HOST | 127.0.0.1 | Bind host for HTTP transport. |
SYNAPSE_MCP_PORT | 40080 | Bind port for HTTP transport. |
SYNAPSE_MCP_TOKEN | unset | Static bearer token for auth. |
SYNAPSE_MCP_NO_AUTH | false | Disable auth for loopback development only. |
SYNAPSE_NOAUTH | false | Delegate auth/authz to an isolated trusted upstream gateway. |
SYNAPSE_MCP_ALLOW_DESTRUCTIVE | false | Skip destructive-operation confirmation prompts (loopback only). |
SYNAPSE_MCP_MAX_CONCURRENCY | 50 | Maximum simultaneous in-flight operational requests. Excess requests receive HTTP 429 with Retry-After. Set to 0 to disable. Public probes, OAuth discovery, and static assets are exempt from concurrency shedding. |
SYNAPSE_MCP_PUBLIC_URL | unset | OAuth public URL; HTTPS required except loopback development. |
SYNAPSE_HOSTS_CONFIG | unset | Inline host topology. Omitted host protocols default to SSH; local execution requires protocol: "local". |
See .env.example for the full list of variables, docs/CONFIG.md for
configuration details, and docs/SECURITY.md for transport, path, transfer,
container, and CI runner trust boundaries.
MCP examples:
Useful docs:
docs/API.md for full tool contractsdocs/CONFIG.md for environment and authdocs/QUICKSTART.md for local smoke testsplugins/synapse/skills/synapse/SKILL.md for agent usage guidancetests/parity.rs for automated parity verification against synapse-mcp INVENTORYThis README is curated for first-run orientation and high-level action discovery. Source-of-truth docs and code are split as follows:
docs/API.md for the curated action contract reference.docs/MCP_SCHEMA.md for MCP schema shape and drift expectations.docs/CONFIG.md for environment and auth policy.docs/QUICKSTART.md for local smoke tests.docs/PLUGINS.md and plugins/synapse/skills/synapse/SKILL.md for agent
and marketplace usage.docs/generated/openapi.json for generated OpenAPI output.src/flux_service/, src/scout_service/, and src/mcp/ for runtime source
of truth.runifi - UniFi controller REST API bridge.rtailscale - Tailscale API bridge for devices, users, and tailnet operations.unraid / runraid - Unraid GraphQL bridge for NAS and server management.rapprise - Apprise notification fan-out bridge for many delivery backends.rgotify - Gotify push notification bridge for sends, messages, apps, and clients.rarcane - Arcane Docker management bridge for containers and related resources.yarr - Media-stack bridge for Sonarr, Radarr, Prowlarr, Plex, and related services.rytdl - Media download and metadata workflow server.cortex - Syslog and homelab log aggregation MCP server.axon - RAG, crawl, scrape, extract, and semantic search project.labby - Homelab control plane and Labby gateway project.lumen - Local semantic code search MCP server.nugs - Project/package management helper for local agent workflows.agentcast - Agent transcript and activity publishing project.soma - RMCP scaffold/runtime template for new provider-backed servers.Original Dinglebear-authored portions of this project are licensed under AGPL-3.0-only. Separate commercial licensing is available for organizations that need terms outside the AGPL. Third-party material remains under its original license. See LICENSING.md.