Summary
Brings deterministic structural analysis of concurrent systems into Claude via seven tools backed by graph theory and Petri net semantics. You hand it EN Diagram source code (a simple text format where actors, actions, and resources connect by name) and ask whether the system can deadlock, whether two systems are equivalent, if paths exist between nodes, what the conservation laws are, or how subsystems compose. Every answer references a named theorem. The `structure` tool maps shape and critical paths, `invariant` checks custom rules like "every path from X to Y passes through a guard", `live` detects siphons and unbounded cycles, and `render` outputs annotated diagrams. Runs via stdio or zero install HTTP transport at api.endiagram.com/mcp. Reach for this when designing workflows, protocols, or pipelines where race conditions and bottlenecks matter more than behavior simulation.
Install to Claude Code
verifiedclaude mcp add --transport http endiagram-mcp https://api.endiagram.com/mcpRun in your terminal. Add --scope user to make it available in every project.
Review the command, arguments, and environment values before installing — MCP servers run with your local permissions.
Keep your Mac awake while Claude Code and 40+ AI agents run. Sleeps when they're idle.
One time payment $9 →
Integrate web data into your AI product. One API to scrape website & brand data.
Get API Key Now →
Agent, run crypto. Access onchain data & trade routes via 1inch.
Install now →
On Capafy, your Skill runs online 24/7 as an agent product, and you get paid every time someone uses it.
Start earning →
Tools
Verified live against the running server on Jun 10, 2026.
verified live7 tools
structureWhat is this system? Returns shape (Pipeline, Fork-Join, DAG, Star, Cycle, Tree, Complete, etc.), stages with roles, bridge nodes, cycles, parallelism, critical path, dominator tree, min-cuts, subsystems, interface nodes, actors (who does what, workload entropy), locations (wh...3 params
What is this system? Returns shape (Pipeline, Fork-Join, DAG, Star, Cycle, Tree, Complete, etc.), stages with roles, bridge nodes, cycles, parallelism, critical path, dominator tree, min-cuts, subsystems, interface nodes, actors (who does what, workload entropy), locations (wh...
Parameters* required
nodestringNode name. When provided, returns per-node centrality (betweenness, closeness, eigenvector) for this specific node instead of the overview.
source*stringEN source code, or path to .en/.txt file
detect_findingsstringSet to 'true' to flag named structural findings. Possible values: unguarded-sink, single-cut-path, multi-cut-path.
invariantWhat's always true — automatic findings and on-demand checks. Automatic outputs: conservationLaws (weighted entity sums constant across executions), sustainableCycles (T-invariants — action sequences returning to start state), depletableSets (entity groups whose simultaneous d...2 params
What's always true — automatic findings and on-demand checks. Automatic outputs: conservationLaws (weighted entity sums constant across executions), sustainableCycles (T-invariants — action sequences returning to start state), depletableSets (entity groups whose simultaneous d...
Parameters* required
rulesstringCustom structural rules, one per line. Four supported sentence shapes (regex-matched): (1) `no bridge that is also hub` — flags nodes that are both a bridge and a hub. (2) `every path from X to Y passes through at least one of [A, B, C]` — encodes precedence/coverage; use to check `A must happen before Y produces Z` by rewriting as `every path from Z's input to Z passes through [A]`. (3) `no node with centrality above 0.5` — flags over-central nodes (replace 0.5 with any threshold). (4) `removing any single node disconnects at most N others` — connectivity robustness check. Unrecognized rules return satisfied:false with an explanation listing these shapes.
source*stringEN source code, or path to .en/.txt file
liveCan it deadlock? Can entities overflow? isStructurallyLive means every siphon contains a trap — no structural deadlock possible. uncoveredSiphons are entity groups that can drain permanently, with the actors and locations affected. isStructurallyBounded means no entity can acc...1 params
Can it deadlock? Can entities overflow? isStructurallyLive means every siphon contains a trap — no structural deadlock possible. uncoveredSiphons are entity groups that can drain permanently, with the actors and locations affected. isStructurallyBounded means no entity can acc...
Parameters* required
source*stringEN source code, or path to .en/.txt file
reachableCan X reach Y? Follows directed data flow first; falls back to undirected. `from` and `to` accept entity names or action names (resolved against the program). Path shows each step with actor and location. locationCrossings counts boundary transitions. defense_nodes checks if g...4 params
Can X reach Y? Follows directed data flow first; falls back to undirected. `from` and `to` accept entity names or action names (resolved against the program). Path shows each step with actor and location. locationCrossings counts boundary transitions. defense_nodes checks if g...
Parameters* required
to*stringTarget node name
from*stringStarting node name
source*stringEN source code
defense_nodesstringComma-separated guard nodes to check coverage
equivalentAre two systems the same, or what changes if I change this one? Compare mode (source_a + source_b): structural differences, edit distance, spectral equivalence. isCospectral=true means identical graph structure up to relabeling — topologically the same despite different names,...4 params
Are two systems the same, or what changes if I change this one? Compare mode (source_a + source_b): structural differences, edit distance, spectral equivalence. isCospectral=true means identical graph structure up to relabeling — topologically the same despite different names,...
Parameters* required
patchstringEN patch for evolve mode. Three directive types: plain EN statement (`actor do: X needs: Y yields: Z at: W`) adds action X; a line starting with `-` (and not containing `do:`) removes the named action; a new statement with an existing action name replaces the original. Multiple directives allowed, one per line.
sourcestringEN source code for evolve mode
source_astringEN source code or path to .en/.txt file for the first system
source_bstringEN source code or path to .en/.txt file for the second system
composeHow do parts combine, or how does a part stand alone? Merge mode (source_a + source_b + links): declare which entities in A are the same as entities in B; the combined graph is wired via string-equality of shared names. Extract mode (source + subsystem): pull a named subsystem...5 params
How do parts combine, or how does a part stand alone? Merge mode (source_a + source_b + links): declare which entities in A are the same as entities in B; the combined graph is wired via string-equality of shared names. Extract mode (source + subsystem): pull a named subsystem...
Parameters* required
linksstringEntity identifications, one per line. Format: `a.<entity name>=b.<entity name>` (A's entity is the same as B's entity). `#` starts a comment. Example: `a.user session=b.authenticated session`.
sourcestringEN source code for extract mode
source_astringEN source code or path to .en/.txt file for the first system
source_bstringEN source code or path to .en/.txt file for the second system
subsystemstringSubsystem name to extract. Valid names come from structure's `subsystems` field — call structure on the source first to discover them.
renderSVG or PNG diagram. Only call when user explicitly asks to visualize. The rendered image is delivered to the user, not injected into the model's context. See the server instructions for EN language syntax.10 params
SVG or PNG diagram. Only call when user explicitly asks to visualize. The rendered image is delivered to the user, not injected into the model's context. See the server instructions for EN language syntax.
Parameters* required
typestringOutput format: png (default) or svg. PNG is rasterized server-side via Batik.
viewstringGroup by: actors (partition by actor) or locations (partition by location). Default auto-detects topology.
colorstringSeed color hex (#RRGGBB) to generate a custom theme. Overrides theme parameter. One color generates the entire palette.
themestringColor theme. Curated presets (each with light + dark variants; pair with `isDark`): `Editorial` (stone paper + rust focal, adapted from cathrynlavery/diagram-design), `Primer` (GitHub design system — blue accent, data-vis roles), `Carbon` (IBM Carbon — sharp 0px corners, corporate blue). Or seed-derived palettes generated on the fly from `color`. Pass 'dark'/'light' for the default variant. Overridden by `color` if provided.
isDarkstringtrue or false. Selects the dark or light variant of a named preset. If omitted, defaults to dark unless theme=light.
outputstringFile path to save the rendered image
source*stringEN source code, or path to .en/.txt file
qualitystringOutput quality: small, mid, or max
directionstringLayout direction: LR (left-to-right) or TB (top-to-bottom). Default auto-detects from condensation DAG aspect ratio.
structure_layersstringBitmask for structure overlays. Bits: 1=subsystems, 2=pipelines, 4=cycles, 8=forks, 16=joins, 32=hubs, 64=deadlock, 128=overflow. Default 255 (all on). Pass 0 to hide all.
@endiagram/mcp
MCP server for EN Diagram — deterministic structural analysis powered by graph theory. Every result is backed by a named mathematical theorem. No AI inside the computation.
Installation
Run directly:
npx @endiagram/mcp
Or install globally:
npm install -g @endiagram/mcp
Connect
Claude Code
claude mcp add endiagram npx @endiagram/mcp
Claude Desktop
Add to your claude_desktop_config.json:
{
"mcpServers": {
"endiagram": {
"command": "npx",
"args": ["@endiagram/mcp"]
}
}
}
Cursor
Add to .cursor/mcp.json in your project root:
{
"mcpServers": {
"endiagram": {
"command": "npx",
"args": ["@endiagram/mcp"]
}
}
}
HTTP (zero install)
Any MCP client that supports HTTP transport:
https://api.endiagram.com/mcp
Smithery
smithery mcp add dushyant30suthar/endiagram
Environment Variables
| Variable | Default | Description |
|---|---|---|
EN_API_URL | https://api.endiagram.com | API endpoint for the EN Diagram service |
Tools
Six questions about any system, plus a render tool. Every tool takes source (EN code or .en/.txt file path). Tool names are shorthand, not specs — read each description before calling; compose and equivalent are mode-based, not general analyzers.
| Tool | What it answers | Levers |
|---|---|---|
structure | What is this system? Shape, stages, bridges, cycles, critical path, dominator tree, min-cuts, subsystems, actors, locations. | detect_findings=true flags risks (unguarded-sink, single-cut-path, multi-cut-path); node=X returns per-node centrality (betweenness, closeness, eigenvector). |
invariant | What's always true? Conservation laws, T-invariants (sustainable cycles), depletable sets, deficiency, reversibility. | rules (one per line) checks custom claims. Four supported shapes: no bridge that is also hub · every path from X to Y passes through at least one of [A,B,C] (precedence) · no node with centrality above N · removing any single node disconnects at most N others. |
live | Can it deadlock? Can entities overflow? Siphons, traps, unbounded cycles, structural liveness and boundedness. | — |
reachable | Can X reach Y? Path, distance, boundary crossings. from/to accept entity or action names. | defense_nodes=a,b,c checks whether guards cover every path. |
equivalent | Are two systems the same, or what changes if I change this one? | Compare mode (source_a+source_b): edit distance + spectral cospectrality. Evolve mode (source+patch): plain EN adds; - name removes; same-name replaces. |
compose | How do parts combine (merge) or how does a part stand alone (extract)? | Merge: source_a+source_b+links (a.entity=b.entity per line). Extract: source+subsystem (names come from structure.subsystems). |
render | SVG or PNG diagram. Only call when the user asks to visualize. | Themes: Editorial, Primer, Carbon (each ± isDark) or seed-derived from color=#RRGGBB. structure_layers bitmask (1=subsystems, 2=pipelines, 4=cycles, 8=forks, 16=joins, 32=hubs, 64=deadlock, 128=overflow). |
EN Syntax
One statement per line:
actor do: action needs: input1, input2 yields: output1, output2
Shared names between yields and needs create connections automatically:
customer do: place order needs: menu yields: order
kitchen do: prepare food needs: order yields: meal
waiter do: deliver needs: meal yields: served customer
Modeling
Same name = same thing. Put all required inputs in one needs: list (AND). Give two actions the same yield-name to offer alternatives (OR). Sequence = one action consuming another's yield. Re-yield stateful resources to keep them persistent; one-shot data stays consumed. Model at the real atomic granularity — split only when the pieces could be accessed independently.
Learn more at endiagram.com.
Telemetry
@endiagram/mcp generates a random install ID on first run, stored at
~/.endiagram/install-id (mode 0600). It is sent with every request as
the X-Endiagram-Install-Id HTTP header so we can correlate requests
from the same install for debugging issues that the per-IP signal alone
cannot track (mobile networks, VPNs, CGNAT all collapse or churn IPs).
No source code, no file paths, no environment variables, and no PII are sent. The install ID is a random opaque UUIDv4 generated locally.
A first-run notice prints to stderr (never stdout — stdout is the MCP JSON-RPC channel) with the disclosure and the opt-out instructions. The notice fires once per install and never again.
Opting out
Any of these three methods disables the install ID:
- Set
ENDIAGRAM_TELEMETRY=offas an environment variable (also accepts0,false,no). - Create a file at
~/.endiagram/telemetrycontaining the wordoff. - Delete
~/.endiagram/install-id. (A new one is generated on next run unless option 1 or 2 is also set.)
When any of these is active, the X-Endiagram-Install-Id header is not
sent at all — the server falls back to its per-IP HMAC cid for
correlation, which works fine for short-term per-session tracing.
Full privacy policy: endiagram.com/privacy
License
MIT
Featured
Keep your Mac awake while Claude Code and 40+ AI agents run. Sleeps when they're idle.
One time payment $9 →Integrate web data into your AI product. One API to scrape website & brand data.
Get API Key Now →Agent, run crypto. Access onchain data & trade routes via 1inch.
Install now →On Capafy, your Skill runs online 24/7 as an agent product, and you get paid every time someone uses it.
Start earning →Categories
Registryactive
Package@endiagram/mcp
TransportSTDIO, HTTP
Tools verifiedJun 10, 2026
UpdatedApr 21, 2026
