GEML — a plain-text document format built to be edited in place, one section at a time

Remove one or more blocks, each named by an id or any address geml_list prints; a filter (`=== type`, `{key=value}`) removes every block it matches. Each block takes the blank line that separated it from its neighbours, so deleting what geml_add inserted leaves the file as it was. To undo a deletion, geml_revert the removed id; to change a block rather than remove it, use geml_set. References left pointing at a removed block come back as diagnostics but do NOT block the deletion — read them, then repair the references or revert. A selector that names nothing is skipped, so repeating a call changes nothing. Returns `{ok, file, diagnostics, revision}`, with `notes` when the write did something to say out loud (a block it dropped, an address it changed); a refusal is `ok: false` with a `hint`, and the file is unchanged. This server is STATELESS: the document travels in `source` and a write comes back as `document` for you to save; it holds no other documents, so a cross-document reference such as `[[other.geml#id]]` cannot be resolved here and is reported as `unresolvable-document`.

Replace ONE block and leave every other byte untouched — prefer this to rewriting a file. For content that does not exist yet use geml_add; to remove a block, geml_delete. The replacement is validated before it is written: if it would break the document, nothing is written and the diagnostics come back — fix the body rather than resending it. Removing content is not refused: if the replacement drops blocks, the write goes through and the result names each one, so check it after shortening a section; geml_revert puts one back. `part` replaces the whole block (default), its head line, a section's `intro`, or its body. In a Markdown file a heading's anchor is its text, as on GitHub: new heading text gives the heading a new address, and the document's links to the old one follow in the same write. GEML content written over a Markdown heading or prose is converted to Markdown, as in geml_add; a GEML block already in the file stays GEML. An `id` that matches no block, or several, is refused. Returns `{ok, file, diagnostics, revision}`, with `notes` when the write did something to say out loud (a block it dropped, an address it changed); a refusal is `ok: false` with a `hint`, and the file is unchanged. This server is STATELESS: the document travels in `source` and a write comes back as `document` for you to save; it holds no other documents, so a cross-document reference such as `[[other.geml#id]]` cannot be resolved here and is reported as `unresolvable-document`.

Convert a WHOLE document and get the result back as text — the read half of the CLI's `geml <file> --to <fmt>`. `to: "geml"` on a Markdown file is the importer, the one thing the block tools cannot do; `to: "md"` projects a GEML document out (lossy); `to: "json"` returns the full document model, for when geml_list plus geml_get is not enough. Nothing is written — pass the result to geml_add or geml_set to land it. `to: "html"` also works but returns a whole self-contained page, usually tens of kilobytes this server cannot save: prefer the CLI (`geml <file> --to html -o out.html`) unless you want the markup in the conversation. A document with errors returns its diagnostics instead of a conversion, and a file that is not under the server root is an error. This server is STATELESS: the document travels in `source` and a write comes back as `document` for you to save; it holds no other documents, so a cross-document reference such as `[[other.geml#id]]` cannot be resolved here and is reported as `unresolvable-document`.

Insert new content — one or more blocks, or prose — at the end of the document (`position: append`) or before/after the block named by `anchor`. Use this for content that does not exist yet; to change a block that does, use geml_set. Ids inside the content are kept. In a `.md` file Markdown lands as written, and GEML content is converted to Markdown as `to: "md"` converts it, the result's `notes` saying so; content Markdown cannot hold, such as a view without its source, is refused. Like every write here it is validated first: a missing anchor, an id that clashes with an existing one, or content that would break the document is refused. Returns `{ok, file, diagnostics, revision}`, with `notes` when the write did something to say out loud (a block it dropped, an address it changed); a refusal is `ok: false` with a `hint`, and the file is unchanged. This server is STATELESS: the document travels in `source` and a write comes back as `document` for you to save; it holds no other documents, so a cross-document reference such as `[[other.geml#id]]` cannot be resolved here and is reported as `unresolvable-document`.

Rename a block id AND every reference to it in the same document, in one id-boundary-safe write. Use this rather than geml_set or a text search-and-replace, which would also hit ids that merely share a prefix. A Markdown heading's anchor is its text, so it is renamed by changing the heading with geml_set (`part: head`), not here. An `old` id that does not exist, or a `new` one already taken, is refused. Returns `{ok, file, diagnostics, revision}`, with `notes` when the write did something to say out loud (a block it dropped, an address it changed); a refusal is `ok: false` with a `hint`, and the file is unchanged. This server is STATELESS: the document travels in `source` and a write comes back as `document` for you to save; it holds no other documents, so a cross-document reference such as `[[other.geml#id]]` cannot be resolved here and is reported as `unresolvable-document`.

Validate a GEML document without changing it: returns every diagnostic with a stable `code`, a severity and a line, and an empty list means the document is valid. Use it to confirm a document is sound before reporting work as finished. Every write through this server runs the same check before it lands, so a refused write already carries this information. This server is STATELESS: the document travels in `source` and a write comes back as `document` for you to save; it holds no other documents, so a cross-document reference such as `[[other.geml#id]]` cannot be resolved here and is reported as `unresolvable-document`.

Search block CONTENT in the document; each hit is one `<name>\t<address>` row. geml_list says what a document contains, this says which block holds the words — as an address that pastes straight into geml_get or geml_set, not a line number the next edit invalidates. The address is the innermost block holding the match, and a block matching on many lines is reported once. Substring, case-insensitive unless `case` is true. No match is an empty result, not an error. This server is STATELESS: the document travels in `source` and a write comes back as `document` for you to save; it holds no other documents, so a cross-document reference such as `[[other.geml#id]]` cannot be resolved here and is reported as `unresolvable-document`.

Read ONE block from a GEML document instead of the whole file: only that block comes back, typically a few percent of the document. Pass the `address` geml_list prints as `id` — it also reaches blocks with no `#id`; to locate a block by its words instead, use geml_find first. An `id` that matches nothing, or a file that is not under the server root, is an error naming it. This server is STATELESS: the document travels in `source` and a write comes back as `document` for you to save; it holds no other documents, so a cross-document reference such as `[[other.geml#id]]` cannot be resolved here and is reported as `unresolvable-document`.

List every addressable block in a GEML document — its address, kind and heading text — in one call, with no paging. Call this FIRST: what it returns is what every other tool here addresses, and it is cheaper and more reliable than reading the file to see what is in it. Rows marked `anon` have no `#id`; geml_get and geml_set take their `address` as `id`, while the other write tools need a real id, so give such a block one first. A file that is not under the server root is an error. This server is STATELESS: the document travels in `source` and a write comes back as `document` for you to save; it holds no other documents, so a cross-document reference such as `[[other.geml#id]]` cannot be resolved here and is reported as `unresolvable-document`.