# Read diagram

> Page: https://docs.plotwork.dev/api/post-v1-diagrams-read. Index of every page: https://docs.plotwork.dev/llms.txt

Read the source back out of a Plotwork SVG.

`POST /v1/diagrams/read`

## TL;DR

| Question | Answer |
|---|---|
| What does it do? | Read the source back out of a Plotwork SVG. |
| Which tool does the same? | [`read_diagram`](https://docs.plotwork.dev/mcp/tools/read-diagram.md) |
| What does it take? | A JSON body of type [`ReadDiagramInput`](https://docs.plotwork.dev/api/schemas.md#readdiagraminput). |
| What does it return? | Status 200 with a body of type [`ReadDiagramResponse`](https://docs.plotwork.dev/api/schemas.md#readdiagramresponse). |
| What can go wrong? | `400` the body failed schema validation, or sent both of svg and url or neither; `401` the api key is missing or not valid; `403` the account is on the free plan, which does not include the rest drawing and checking routes (plan.rest_not_included); `413` the body is larger than the size cap; `429` too many requests. Every failure uses the one error envelope. |

## What it does

Send the text of a Plotwork SVG or the link of a hosted one (cdn.plotwork.dev only). Returns the exact source the picture was drawn from, its kind, the stored diagram id, and a check of the source. A picture made without embedSource has no source: the answer says so (status no-source) and returns its title, outline, and labels. Problems with the text or the link are answers, not errors.

## Request body

The body has the type [`ReadDiagramInput`](https://docs.plotwork.dev/api/schemas.md#readdiagraminput).

| Field | Type | Required | Description |
|---|---|---|---|
| `svg` | `string` | no | The text of a Plotwork SVG: the content of an .svg file in the repository. Send this or url, not both. at least 1 character; at most 1000000 characters. |
| `url` | `string` | no | The link of a hosted Plotwork picture, https://cdn.plotwork.dev/d/<22 characters>.svg. Only Plotwork's own picture hosts are fetched. Send this or svg, not both. at least 1 character; at most 200 characters. |

## Responses

| Status | Meaning | Body |
|---|---|---|
| 200 | The source, or why there is none. | [`ReadDiagramResponse`](https://docs.plotwork.dev/api/schemas.md#readdiagramresponse) |
| 400 | The body failed schema validation, or sent both of svg and url or neither. | [`ErrorResponse`](https://docs.plotwork.dev/api/schemas.md#errorresponse) |
| 401 | The API key is missing or not valid. | [`ErrorResponse`](https://docs.plotwork.dev/api/schemas.md#errorresponse) |
| 403 | The account is on the Free plan, which does not include the REST drawing and checking routes (plan.rest_not_included). | [`ErrorResponse`](https://docs.plotwork.dev/api/schemas.md#errorresponse) |
| 413 | The body is larger than the size cap. | [`ErrorResponse`](https://docs.plotwork.dev/api/schemas.md#errorresponse) |
| 429 | Too many requests. | [`ErrorResponse`](https://docs.plotwork.dev/api/schemas.md#errorresponse) |

## Response body

A 200 answer has the type [`ReadDiagramResponse`](https://docs.plotwork.dev/api/schemas.md#readdiagramresponse).

| Field | Type | Required | Description |
|---|---|---|---|
| `status` | `"read" \| "no-source" \| "damaged" \| "not-a-picture" \| "refused" \| "unreachable"` | yes | read: the source was found. no-source: the picture carries none. damaged: it carries one that cannot be read back. not-a-picture: the text is not an SVG. refused: the link is not one this tool fetches. unreachable: the link could not be fetched. |
| `hasSource` | `boolean` | yes | True when source is set. |
| `source` | `string \| null` | yes | The exact source the picture was drawn from, ready to edit and send to draw_diagram; null when there is none. |
| `kind` | `string \| null` | yes | The diagram kind of the source, or null. |
| `id` | `string \| null` | yes | The id of the stored diagram when the picture was published (data-plotwork-id), or null. |
| `from` | `"text" \| "url"` | yes | Where the picture came from: the text that was sent, or the link that was fetched. |
| `validation` | `object \| null` | yes | The check of the source, or null when there is none. It parses the source; draw_diagram also lays it out and returns warnings. |
| `validation.valid` | `boolean` | yes | True when the source has no errors. |
| `validation.errors` | `Diagnostic[]` | yes | Every error, each with line, column, and a hint; empty when valid. |
| `validation.errors[].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. |
| `validation.errors[].severity` | `"error" \| "warning"` | yes | Errors stop rendering; warnings never do. |
| `validation.errors[].message` | `string` | yes | What is wrong, in one sentence. |
| `validation.errors[].line` | `integer` | yes | 1-based line in the submitted source. minimum 1. |
| `validation.errors[].column` | `integer` | yes | 1-based column in that line. minimum 1. |
| `validation.errors[].length` | `integer` | yes | Number of characters the problem covers. minimum 1. |
| `validation.errors[].hint` | `string \| null` | yes | A concrete suggestion for fixing it, or null. |
| `validation.summary` | `string \| null` | yes | One-line description of the diagram, or null when invalid. |
| `picture` | `object \| null` | yes | What the picture says about itself, or null when the text is not an SVG. |
| `picture.title` | `string \| null` | yes | The diagram title, or null. |
| `picture.summary` | `string \| null` | yes | The one-line summary the picture carries, or null. |
| `picture.theme` | `string \| null` | yes | The color scheme it was drawn in, or null. |
| `picture.size` | `object \| null` | yes | Its size in px, or null. |
| `picture.size.width` | `integer` | yes | Width in px. minimum 1. |
| `picture.size.height` | `integer` | yes | Height in px. minimum 1. |
| `picture.outline` | `string[]` | yes | The plain-language outline the picture carries, one entry for each line. Empty when the source was read: the source says more. |
| `picture.labels` | `string[]` | yes | The text painted on the picture, each distinct label once, in painted order. Empty when the source was read. |
| `message` | `string` | yes | What happened, in one sentence. |
| `next` | `string` | yes | The next step in one sentence. |

## See also

| Doc | Why |
|---|---|
| [API reference](https://docs.plotwork.dev/api/reference.md) | Every endpoint, and the error envelope |
| [Schemas](https://docs.plotwork.dev/api/schemas.md) | Every request and response type |
| [`read_diagram`](https://docs.plotwork.dev/mcp/tools/read-diagram.md) | The same operation as an MCP tool |
| [Tool reference](https://docs.plotwork.dev/mcp/tools.md) | The operations as callable tools |