neocursor.nvim

Cursor's Tab — the real next-edit model — inside Neovim.

_{Renamed one field on line 3. The two call sites below are now stale. <Tab> jumps to each one · <Tab> again accepts the rewrite.}

No API key. No model to choose. No account to create. If you're already signed into Cursor, there is nothing else to set up — neocursor drives Cursor's own StreamCpp backend with your existing login, so you get the same predictions, at the same latency, as Cursor itself.

Warning

Beta. The goal is 1:1 parity with Cursor's Tab, and most of it is there. See Cursor Tab parity for the honest scoreboard.

Requirements · Installation · Usage · Configuration · Parity · How it works · Troubleshooting

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Requirements

• Neovim ≥ 0.10
• Cursor, installed and signed in (the desktop app) — neocursor reads your existing session. No token to paste, no API key, no separate subscription.
• uv on your PATH — the Python sidecar runs through it and fetches its own deps. Nothing to pip install.

Works on macOS, Linux and Windows; the sidecar finds Cursor's session wherever your platform puts it. Portable install, Flatpak/Snap, or WSL? See Cursor can't be found.

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Installation

lazy.nvim

{
  "teocns/neocursor.nvim",
  event = "InsertEnter",
  -- pre-warm the sidecar (double quotes so cmd.exe and sh both parse it)
  build = 'uv run --with "httpx[http2]" python -c "import httpx"',
  opts = {},
}

That's the entire setup. No tokens, no required setup() arguments — open a file, start typing, pause → ghost text → <Tab>.

vim.pack

Built into Neovim ≥ 0.12:

vim.pack.add { "https://github.com/teocns/neocursor.nvim" }
require("neocursor").setup {}

More setups → docs/installation.md: full vim.pack parity with the lazy.nvim spec, coexisting with nvim-cmp / blink.cmp, and pinning a version.

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Usage

Type, pause, and a suggestion appears. Then:

Key / Command	Does
<Tab>	Accept · or jump to the predicted next edit · or chain to the next one
<M-Right>	Accept the suggestion word-by-word
<C-]>	Dismiss
:NeocursorSuggest	Force a request right now
:NeocursorLog	Toggle the live state dashboard
:NeocursorDebug	Print diagnostics

The tab-tab-tab flow

One key does three jobs, in Cursor's exact rhythm — accept, then jump, then accept again:

flowchart LR
    T["you type, then pause"] --> G["ghost text / diff appears"]
    G -->|Tab| A["edit applied"]
    A --> Q{"Cursor predicts an<br/>edit elsewhere?"}
    Q -->|"yes"| P["jump pill appears<br/>⟪Tab → L42⟫"]
    P -->|Tab| J["cursor jumps there"]
    J -->|Tab| A
    Q -->|"no"| T

Loading

The loop back through jump → accept is what makes it feel like Cursor rather than a completion engine: you keep pressing the same key and the edits come to you.

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Configuration

Every option is optional. This is the complete set, at its defaults:

require("neocursor").setup({
  debounce    = 250,
  map_tab     = true,
  map_partial = "<M-Right>",
  filetypes   = nil,
  show_hints  = true,
  sidecar_cmd = { "uv", "run", "--with", "httpx[http2]" },
})

Option	Type	Description
debounce	number	Idle milliseconds before a request. Overridden by Cursor's CppConfig at startup.
map_tab	boolean	false leaves <Tab> unmapped so nvim-cmp / blink.cmp can own it.
map_partial	string | false	Key for word-by-word accept. false disables it.
filetypes	string[] | nil	Allow-list, e.g. { "python", "lua" }. nil means every normal buffer.
show_hints	boolean | table	Hint chrome. false hides it; a table hides one surface.
sidecar_cmd	string[]	How the Python sidecar launches. Override only for unusual setups.

Full reference → docs/configuration.md: what each option does, why debounce is usually overridden, and which hint surface you actually want to keep.

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Cursor Tab parity

The goal is a 1:1 port of Cursor's Tab — here's what actually made it across, and what's still in flight:

Cursor Tab capability	neocursor
Inline multi-line completions (ghost text)	✅
Diff-style rewrites of existing lines	✅
Next-edit prediction + cursor jump (the tab-tab-tab flow)	✅
Multi-edit chains — one <Tab> per edit, no extra round-trips	✅
Recent-edit / diff-history context	✅
Nearby-file + linter-error context	✅
Request gating — stays quiet while you read/navigate	✅
Partial accept (word-by-word)	✅
Config pulled live from Cursor (CppConfig: debounce, heuristics)	✅
macOS / Linux / Windows auth paths	✅
Character-level diffs for single-character edits	🚧
Cross-file apply on jump targets	🚧 partial — jump lands, chain is partial

_{✅ ported · 🚧 in progress}

The core loop — predict, ghost, <Tab>, jump, chain — is complete and running on Cursor's actual backend. The 🚧 rows are edges, not the main path.

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How it works

neocursor doesn't reimplement or retrain a model — it is Cursor's Tab, reached through a tiny stdio bridge:

flowchart LR
    NV["<b>Neovim</b><br/><code>lua/neocursor</code><br/>ghost text · diffs · owns Tab"]
    SC["<b>sidecar.py</b><br/>reads your Cursor session<br/>forges the checksum"]
    CU["<b>Cursor StreamCpp</b><br/><code>api2.cursor.sh</code>"]

    NV -->|"buffer, cursor, edit history<br/>(JSON over stdio)"| SC
    SC -->|"Connect / protobuf over h2"| CU
    CU -.->|"streamed edits<br/>+ next-jump target"| SC
    SC -.->|"JSON"| NV

Loading

The sidecar reads your local Cursor session, speaks the exact StreamCpp call Cursor's own client makes, and streams back the edit sequence plus the next cursor-jump target. Your token never leaves the machine, and the Lua side never touches the network — that boundary is deliberate.

See NOTICE for rendering-technique attribution.

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Troubleshooting

Start with :NeocursorDebug (resolved config, sidecar state, last error) and :NeocursorLog (live event stream). Between them, most problems name themselves.

Full guide → docs/troubleshooting.md: Cursor can't be found, the sidecar won't start, no suggestions appear, <Tab> does nothing, and what to include in a bug report.

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Contributing

Issues and PRs welcome — see CONTRIBUTING.md for the project layout, how to run the specs, and what makes a bug report actionable.

Reporting something? Include :NeocursorDebug output, plus uv run cursor_paths.py for anything path- or auth-related.

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Legal

Independent, personal-use interoperability project — not affiliated with Anysphere / Cursor. It uses your own account; the token never leaves your machine. It talks to Cursor's private API, which is undocumented and may change, and using it may not fit Cursor's ToS — that's between you and Cursor. No Cursor source is redistributed. Use at your own risk.

License

MIT. Rendering-technique attribution lives in NOTICE.