# convert_mermaid

> Page: https://docs.plotwork.dev/mcp/tools/convert-mermaid. Index of every page: https://docs.plotwork.dev/llms.txt

Converts one Mermaid diagram (flowchart or graph, sequenceDiagram, erDiagram, gitGraph, gantt, classDiagram, stateDiagram, timeline, journey, mindmap, treemap-beta or treemap, pie, quadrantChart, C4Context or C4Container or C4Component or C4Dynamic or C4Deployment, sankey-beta or sankey, xychart-beta or xychart, treeView-beta or treeView) to Plotwork source. It is a workflow of the MCP server and the HTTP API, with the title "Convert Mermaid".

## TL;DR

| Question | Answer |
|---|---|
| What is it? | A workflow: one call does the work of several tools and returns one combined answer. |
| What does it do? | Converts one Mermaid diagram (flowchart or graph, sequenceDiagram, erDiagram, gitGraph, gantt, classDiagram, stateDiagram, timeline, journey, mindmap, treemap-beta or treemap, pie, quadrantChart, C4Context or C4Container or C4Component or C4Dynamic or C4Deployment, sankey-beta or sankey, xychart-beta or xychart, treeView-beta or treeView) to Plotwork source. |
| What does it replace? | convert, validate_diagram, outline_diagram and render_diagram calls. |
| How do I call it over HTTP? | [`POST /v1/diagrams/convert-mermaid`](https://docs.plotwork.dev/api/post-v1-diagrams-convert-mermaid.md) |
| Does it change anything? | No. It is read-only and idempotent, and it talks to nothing outside itself. It saves no file and returns its answer as data. |
| Which bounds apply? | None beyond the limits of each argument, which are in the schema below. |
| Where do I read its schema as data? | An MCP client gets the name, description, and JSON Schema of every tool from `tools/list`. |

## What it does

Workflow. Converts one Mermaid diagram (flowchart or graph, sequenceDiagram, erDiagram, gitGraph, gantt, classDiagram, stateDiagram, timeline, journey, mindmap, treemap-beta or treemap, pie, quadrantChart, C4Context or C4Container or C4Component or C4Dynamic or C4Deployment, sankey-beta or sankey, xychart-beta or xychart, treeView-beta or treeView) to Plotwork source. Returns the source, a diagnostic with a hint for everything dropped or changed (styling, links, activations), the check of the result with its icon and group-type suggestions, and an outline; render true also draws it, with picturesOmitted, viewUrl, pngUrl, and saveCommand as in draw_diagram. A Mermaid type Plotwork does not draw comes back as one diagnostic saying what to do instead. Deterministic: never throws on bad input, does not fetch URLs or read files. For a whole Markdown document use sync_markdown with convertMermaid true. Replaces the convert, validate_diagram, outline_diagram and render_diagram calls.

## Steps

| Operation | Runs | What it does |
|---|---|---|
| `convertMermaid` | always | Convert one Mermaid diagram to Plotwork source. |
| `validate` | only when needed | Parse the source and lint it: every error, and the quality, icon, and group-type warnings. |
| `outline` | only when needed | Describe a valid diagram as plain text. |
| `render` | only when needed | Lay out and paint a valid diagram in one color scheme. |

One call performs at most 5 operations.

## Example call

The arguments of the call, as JSON:

```json
{
  "source": "flowchart LR\n  user([User]) --> api[Auth API]\n  subgraph data [Data]\n    db[(Users DB)]\n  end\n  api -->|look up| db\n  api --> check{Valid?}\n  check -->|yes| ok([Signed in])",
  "render": false
}
```

The `source` argument, written out one line at a time:

```mermaid-source
flowchart LR
  user([User]) --> api[Auth API]
  subgraph data [Data]
    db[(Users DB)]
  end
  api -->|look up| db
  api --> check{Valid?}
  check -->|yes| ok([Signed in])
```

## Prompts that lead to it

- Convert this Mermaid flowchart to Plotwork.
- Migrate this Mermaid diagram to Plotwork and tell me what was lost.

## Arguments

| Field | Type | Required | Description |
|---|---|---|---|
| `source` | `string` | yes | One Mermaid diagram: a flowchart or graph, sequenceDiagram, erDiagram, gitGraph, gantt, classDiagram, stateDiagram, timeline, journey, mindmap, treemap-beta or treemap, pie, quadrantChart, C4Context or C4Container or C4Component or C4Dynamic or C4Deployment, sankey-beta or sankey, xychart-beta or xychart, or treeView-beta or treeView. Front matter and %%{init}%% directives are allowed and are dropped. Send the text inside a mermaid fence, without the fence. at least 1 character; at most 50000 characters. |
| `lenient` | `boolean` | no | false (the default): a line that cannot be read stops the conversion, so nothing is converted with a line missing. true: such a line is skipped with a warning and the rest is converted. default false. |
| `render` | `boolean` | no | Also draw the converted diagram, in the color schemes themes names. default false. |
| `themes` | `"light" \| "dark" \| "both"` | no | light, dark, or both (the default): the light picture and the dark one a dark page needs. default "both". |
| `detail` | `"summary" \| "full"` | no | summary (the default), or full: the whole outline, and the source embedded in each SVG. default "summary". |
| `svg` | `"auto" \| "always" \| "never"` | no | auto (the default) returns the SVGs, but over MCP leaves them out when the answer would be too big for a client (picturesOmitted). always returns them at any size. never draws nothing, which is cheaper. The HTTP API treats auto as always. default "auto". |
| `embedSource` | `boolean` | no | Write the source into each SVG so read_diagram can give it back. Set it when you save the SVG in a repository or publish it to edit later; anyone with the file or link can then read the source. default false. |
| `settings` | `object` | no | The repo's plotwork.config.json, if any. Schema: https://docs.plotwork.dev/schemas/plotwork.config.json. |

## Result

| Field | Type | Required | Description |
|---|---|---|---|
| `ok` | `boolean` | yes | True when `source` is valid Plotwork source. False means nothing was converted and `source` is empty: read `diagnostics`. |
| `kind` | `string \| null` | yes | The Plotwork kind the diagram became, or null when it could not be converted. |
| `mermaidType` | `string \| null` | yes | The Mermaid diagram type read from the first line, such as flowchart or sequenceDiagram; null when none was found. |
| `source` | `string` | yes | The Plotwork source, or an empty string when nothing could be converted. |
| `diagnostics` | `Diagnostic[]` | yes | Everything dropped, changed, or wrong, with a hint that says what to do. Codes start with M. Lines and columns point into the Mermaid you sent. M1xx codes are errors that stop the conversion; M2xx codes are warnings and the conversion went on. |
| `diagnostics[].code` | `"E100" \| "E101" \| "E110" \| "E111" \| "E120" \| "E121" \| "E122" \| "E123" \| "E124" \| "E125" \| "E130" \| "E131" \| "E132" \| "E133" \| "E134" \| "E135" \| "E136" \| "E137" \| "E138" \| "E139" \| "E140" \| "W200" \| "W201" \| "W202" \| "W203" \| "W204" \| "W205" \| "W206" \| "W207" \| "W500" \| "M100" \| "M101" \| "M102" \| "M103" \| "M104" \| "M110" \| "M200" \| "M201" \| "M202" \| "M203" \| "M204" \| "M205" \| "M206" \| "M207" \| "M208" \| "M209" \| "M210" \| "M211" \| "M212" \| "M213" \| "M214" \| "M215" \| "M216" \| "M217" \| "M218" \| "E300" \| "E301" \| "E302" \| "E303" \| "E304" \| "W300" \| "W301" \| "W302" \| "W303" \| "M120" \| "M220" \| "M221" \| "M222" \| "E340" \| "E341" \| "E342" \| "E343" \| "E344" \| "E345" \| "W320" \| "W321" \| "W322" \| "W323" \| "M240" \| "M241" \| "M242" \| "E360" \| "E361" \| "E362" \| "E363" \| "E364" \| "E365" \| "E366" \| "E367" \| "W330" \| "W331" \| "W332" \| "W333" \| "W334" \| "M250" \| "M251" \| "E400" \| "E401" \| "E402" \| "E403" \| "W350" \| "W351" \| "W352" \| "W353" \| "M270" \| "M271" \| "E420" \| "E421" \| "E422" \| "E423" \| "E424" \| "W360" \| "W361" \| "W362" \| "W363" \| "W364" \| "M180" \| "M280" \| "M281" \| "M282" \| "E320" \| "E321" \| "E322" \| "E323" \| "E324" \| "E325" \| "E326" \| "E327" \| "E328" \| "E329" \| "E330" \| "W310" \| "W311" \| "W312" \| "W313" \| "W314" \| "M130" \| "M131" \| "M132" \| "M230" \| "M231" \| "M232" \| "M233" \| "M234" \| "M235" \| "M236" \| "M237" \| "M238" \| "E380" \| "E381" \| "E382" \| "E383" \| "W340" \| "W341" \| "W342" \| "W343" \| "M260" \| "I100" \| "I101" \| "I102" \| "I103" \| "I104" \| "I105" \| "I200" \| "I201" \| "I202" \| "I203" \| "I204" \| "I206" \| "R100" \| "R101" \| "R200" \| "R201" \| "R202" \| "R203" \| "R204" \| "R205" \| "R206" \| "R207" \| "S100" \| "S200" \| "S101" \| "S102" \| "S103" \| "S104" \| "S201" \| "S202" \| "S203"` | yes | Stable code to branch on; E-codes are errors, W-codes are warnings. |
| `diagnostics[].severity` | `"error" \| "warning"` | yes | Errors stop rendering; warnings never do. |
| `diagnostics[].message` | `string` | yes | What is wrong, in one sentence. |
| `diagnostics[].line` | `integer` | yes | 1-based line in the submitted source. minimum 1. |
| `diagnostics[].column` | `integer` | yes | 1-based column in that line. minimum 1. |
| `diagnostics[].length` | `integer` | yes | Number of characters the problem covers. minimum 1. |
| `diagnostics[].hint` | `string \| null` | yes | A concrete suggestion for fixing it, or null. |
| `stats` | `object` | yes |  |
| `stats.nodes` | `integer` | yes | Flow nodes written. |
| `stats.edges` | `integer` | yes | Flow edges written. |
| `stats.groups` | `integer` | yes | Flow groups written. |
| `stats.actors` | `integer` | yes | Sequence participants written. |
| `stats.messages` | `integer` | yes | Sequence messages written. |
| `stats.tables` | `integer` | yes | Schema tables written. |
| `stats.columns` | `integer` | yes | Schema columns written. |
| `stats.relations` | `integer` | yes | Schema relations written. |
| `stats.dropped` | `integer` | yes | Warnings about constructs that were dropped: styling, links, activations, and so on. |
| `stats.renamed` | `integer` | yes | Ids that were not valid Plotwork ids and were renamed. |
| `validation` | `object \| null` | yes | The Plotwork validator run on `source`; null when nothing was converted. |
| `quality` | `Quality` | no | How clean the converted diagram looks and up to three changes that would help (see draw_diagram); absent when it is not valid. |
| `quality.score` | `integer` | yes | 0 to 100; 100 is a picture with nothing to fix. The same diagram always gets the same score. minimum 0; maximum 100. |
| `quality.grade` | `"clean" \| "fair" \| "cluttered"` | yes | clean is 85 or more, fair 60 or more, cluttered below. |
| `quality.measures` | `object` | yes | What the score is made from: crossings, lineOverBox, labelOverlaps, smallestTextPx (in an 880px column), aspectRatio, emptySpace (0 to 1), longestLine (px), detour (1 is straight), the counts of boxes, lines, labels, series, and slices, and any measure the kind adds. |
| `quality.hints` | `string[]` | yes | Up to three changes, the one worth most first, each naming the statement or option to edit. |
| `quality.line` | `string` | yes | The grade, the score, and the first hint in one line. |
| `outline` | `string[]` | yes | The converted diagram as plain text, to check it says what the Mermaid said; empty when nothing was converted. |
| `outlineTruncated` | `boolean` | yes | True when the summary level cut the outline short. Call again with detail "full" to read all of it. |
| `renders` | `object[]` | yes | One picture per requested color scheme, light first; empty unless `render` was true and the conversion is valid, when svg is never, and when every picture was left out (see picturesOmitted). |
| `renders[].theme` | `"light" \| "dark"` | yes | The color scheme this picture is drawn in. |
| `renders[].svg` | `string` | yes | Self-contained SVG markup with an accessible title and description. |
| `renders[].size` | `Size` | yes | Natural size of a rendered diagram in px. |
| `renders[].size.width` | `integer` | yes | Width in px. minimum 1. |
| `renders[].size.height` | `integer` | yes | Height in px. minimum 1. |
| `picturesOmitted` | `object` | no | Present only when pictures were left out because the answer would have been too big for an AI client to read in one piece. |
| `picturesOmitted.themes` | `("light" \| "dark")[]` | yes | The color schemes whose pictures were left out. |
| `picturesOmitted.characters` | `integer` | yes | How many characters the pictures left out came to. |
| `picturesOmitted.limit` | `integer` | yes | The most characters one answer may hold before the pictures are left out. |
| `picturesOmitted.why` | `string` | yes | Why they were left out, and what to do. |
| `viewUrl` | `string` | no | A link that shows a valid diagram in a browser; give it to the person who wants to look. The source is in the part after #, never sent to a server, but anyone with the link can read it. Absent when too long; next says so. |
| `pngUrl` | `string` | no | The viewUrl with &download=png: opening it in a browser saves the diagram as a PNG for Slack, email, or a wiki. The PNG is drawn in the person's browser, not on a server, so it is a link to open, not an image address to embed. Absent when too long. |
| `svgUrl` | `string` | no | The viewUrl with &download=svg: a person opens it to download the SVG. Not a file address for curl; use saveCommand. Absent when too long. |
| `saveCommand` | `string` | no | Run in a shell to save the SVG into the repository: the CLI decodes the link locally, fetches nothing, and embeds the source. Set --out to the path; add --theme dark for dark. Absent when too long. |
| `next` | `string` | yes | The next step in one sentence. |

## Behavior hints

| Hint | Value |
|---|---|
| `readOnlyHint` | true |
| `destructiveHint` | false |
| `idempotentHint` | true |
| `openWorldHint` | false |

## See also

| Doc | Why |
|---|---|
| [Tool reference](https://docs.plotwork.dev/mcp/tools.md) | Every tool, with the workflows first |
| [`POST /v1/diagrams/convert-mermaid`](https://docs.plotwork.dev/api/post-v1-diagrams-convert-mermaid.md) | The same operation over HTTP |
| [Language reference](https://docs.plotwork.dev/reference/language.md) | What the diagram source may contain |
| [Writing diagrams with an agent](https://docs.plotwork.dev/mcp/agent-loop.md) | The loop in practice |