| name | mermaid |
| description | Create concise, syntax-verified Mermaid architecture diagrams. Use when the user asks to diagram a repository component, document, system, dependency flow, or supplied description in Mermaid. |
| allowed-tools | Bash(npx -y @mermaid-js/mermaid-cli@11.16.0:*), Write, Read |
Draw a mermaid architecture diagram in markdown for: $ARGUMENTS
Conventions
- Boxes are services/components:
svc[bex-api]. Use [(...)] for datastores. Humans (user, developer, operator) are triangles: user@{ shape: tri, label: "user" }.
- A box that is not a long-running service must say so in its label — readers assume boxes are services and ask "where is this running?". Mark scheduled/ephemeral work (
cron["backup pod (spawned nightly, exits when done)"]) and inert config objects (secret["Secret foo (k8s object, created once)"]). Draw humans as triangles: operator@{ shape: tri, label: "operator" }. Never draw a manual procedure as a peer box of running infrastructure: give runbook/recovery flows their own subgraph whose title says it's manual and where it runs (subgraph "disaster recovery — manual runbook, any docker host"), with the human actor inside.
- Arrows are dependency direction:
A --> B means A depends on (calls, reads, deploys to) B — never the reverse.
- Concise but to the point: only load-bearing services and edges. No styling, no colors, no legend. Label an edge (
A -->|gRPC| B) only when the relationship isn't obvious. Default to flowchart TB; use LR only if the graph is much wider than deep. Use subgraph only for real boundaries (cluster, node, network, trust zone, automated vs. manual) — subgraphs are how the diagram answers "where does this run?". An edge may target a whole subgraph by id (subgraph cluster["app cluster"] … op --> cluster).
- If $ARGUMENTS refers to this repo, read the relevant docs/code first (
docs/ADR002-architecture.md is the map) — don't diagram from guesswork.
Syntax gotchas that break rendering: quote labels containing (, ), [, {, or -->-like text (a["Queue (SQS)"]); never name a node bare end or graph; subgraph titles with spaces need quotes.
Verify (mandatory, before answering)
- Write the diagram body (no
```mermaid fence) to a .mmd file in the scratchpad.
- Run:
npx -y @mermaid-js/mermaid-cli@11.16.0 -i <file>.mmd -o <file>.svg — exit 0 means the syntax is valid. (First run downloads a headless browser; that's expected.) The version is pinned deliberately (supply-chain: codex-security #17) — bump it consciously, don't revert to floating.
- On failure, read the parse error, fix the diagram, and re-verify. Never output a diagram that hasn't passed.
Output
A single ```mermaid fenced block, followed by at most 2 sentences explaining the key dependency flow. If the user asked to put the diagram into a file, insert the verified block there instead.
