Gneiss — AI Writing Assistant

A VSCode extension where you control the argument's skeleton and delegate low-level tasks for AI agents that 'fill in the blanks'. Targetted towards academic, formal, and research writing — Gneiss works with LaTeX, Markdown, and any other file type. Our vision is to recentre humans in the writing process, integrating LLMs as 'blanks' in your text so you can write at the speed of thought without sacrificing control.

For example, as you being drafting the motivation for a paper, you might write:

The seminal result by ⟨citation⟩ introduced the transformer architecture, which ⟨one-sentence summary of key contribution⟩.

Then press Option+S (to fill in blanks sequentially in a token-efficient manner). Gneiss automatically delegates agents to complete these blanks with smart context construction: agents can browse the web, query files in your repo, and reference bibtex citations to fill in your blanks (for Gneiss' first-class file access and bibtex support, see here).

When we ran Gneiss on the above example, it produced:

The seminal result by Vaswani et al. (2017) introduced the transformer architecture, which is a network architecture based solely on attention mechanisms, dispensing with recurrence and convolutions entirely.

Getting Started

1. Install the Gneiss extension.
2. Configure your API key (see Configuration below).
3. Open a document, press Cmd+[ to create a blank, type an instruction, and click Fill.

Usage

Creating Blanks

Press Cmd+[ to insert a blank at your cursor. A ⟨⟩ pair appears and you can type a natural-language instruction inside it.

For example, you might write:

The seminal result by ⟨citation⟩ introduced the transformer architecture, which ⟨one-sentence summary of key contribution⟩.

You can also select text first, then press Cmd+[ — the selection becomes the instruction.

Blanks are directly editable: click into the ⟨instruction⟩ text to modify it at any time. CodeLens actions (Fill and Delete) appear above lines with pending blanks.

Filling Blanks

Click the Fill CodeLens above any blank, or use one of the batch fill modes:

Each fill produces an inline diff. Press Cmd+Y to accept or Cmd+N to reject.

References

Type @ inside a blank to reference files from your workspace. The agent receives their content as context.

Autocomplete suggestions appear as you type, with icons distinguishing file types. For .bib files, typing : after the filename triggers cite key completions showing key, title, author, and year.

@model: Override

Override the LLM provider and model for individual blanks:

⟨@model:claude:claude-sonnet-4-5 synthesise the argument from sections 2 and 3⟩
⟨@model:ollama:llama3:8b year of publication⟩

This lets you mix models within a document — e.g. a fast/cheap model for simple lookups and a more capable model for complex synthesis. Blanks without @model: use your global default. The directive is stripped before reaching the model.

Autocomplete helps here too: typing @model: suggests providers (claude, ollama), and typing further (e.g. @model:claude:) suggests available models.

Agent Tools

The filling agent has access to tools it can use autonomously:

• Web search — the agent can search the web for facts, citations, and context (Claude uses native web search; Ollama requires an API key from ollama.com/settings/keys)
• **read_file** — read any file in your workspace (text files, .bib, and PDFs)
• **search_files** — grep-style search across workspace files
• **list_directory** — browse directories

You don't need to @-reference everything — the agent can explore your workspace on its own. But explicit @ references are more reliable and avoid extra tool-call latency.

File Access Control

Create a .gneissignore file in your workspace root to exclude files from agent access. Uses regex patterns, one per line:

# Ignore build artifacts
build/.*
dist/.*

# Ignore drafts
drafts/.*\.tex

Files matching .gitignore patterns are also excluded by default (controlled by the gneiss.repo.respectGitignore setting).

Keybindings

All keybindings are remappable via VSCode's standard keybindings.json.

Note: Cmd+[ overrides VSCode's "Outdent Line" — use Shift+Tab for outdenting instead.

Configuration

Claude

Your API key is detected automatically from the ANTHROPIC_API_KEY environment variable, or set it in settings: gneiss.llm.claude.apiKey.

Ollama

General