What is Nestbolt?
Nestbolt arranges 2D parts on fixed sheets so they use the least material, for people cutting with lasers, CNC routers, plasma, waterjet, fabric or leather. It imports SVG, DXF and LightBurn projects, places small parts inside the holes of larger ones, spreads a job across several sheets and stock sizes, and exports one SVG and DXF per sheet from the original curves. Every layout is checked by an independent Clipper2 validator before it is returned.
The same Rust engine runs as a browser app (WebAssembly, nothing uploaded), a command-line tool and a stdio MCP server, nestbolt-mcp, with five tools: import_parts, nest, validate_layout, export_layout and estimate_sheets. It builds on the jagua-rs and Sparrow research codebases by Jeroen Gardeyn. The project is MIT-licensed, was created on 11 October 2026 by a single author, and has about 11 GitHub stars; v0.1.0 shipped on 14 October and v0.2.0-alpha.1 on 16 October 2026.
How to install Nestbolt
Download nestbolt-mcp from GitHub releases (or cargo build --release -p nestbolt-mcp)Is Nestbolt worth it?
Nestbolt is unusually careful about evidence for a project this young. Its frozen benchmark ran 75 sheet jobs, ten held out from tuning, with equal time budgets and one CPU core per tool, and reports a median 8.5% less material than the best of Deepnest, SVGnest and Sparrow at 60 seconds and 9.6% at 300 seconds. It also publishes where it loses: Sparrow, which it builds on, wins 8 of the 56 comparable jobs at 60 seconds, and the project admits that misses its own target. These are the author's numbers, not an independent test, but every run, seed and failure is published and reproducible from a script.
The MCP server is built for agents rather than bolted on. Geometry stays in files and replies are capped at 200 summary entries, so a 400-part job does not flood the context window. Paths must sit inside one workspace folder, outputs never overwrite existing files, and a nest run with the same inputs, work budget and seed returns the same layout, which makes an agent's result something a person can rerun and check. The nest tool accepts a time budget of up to 300 seconds.
The practical gaps are those of an alpha. There is no package-manager install: you download a release archive or build with Cargo, then register the binary by absolute path. LightBurn import, lead-in allowances and common-line cutting are in the preview build, and the docs say common-line cutting can raise material use and two development jobs exceed its planned limit. Exports still go through your CAM software, which creates the actual leads.
For a small shop, the comparison that matters is with Deepnest and SVGnest, the free tools most people reach for. On the published numbers Nestbolt beats Deepnest on all 55 jobs where Deepnest produced a layout, at a median 9.9%, and SVGnest on all 36 at 14.4%. On a sheet of plywood or acrylic that is real money, provided the project keeps going; at 11 stars and one author, that is the open question.
Where it earns its place
A two-person laser-cutting shop making plywood kits
Fit a 138-part order onto as few 2440 x 1220 mm sheets as possible
Ask the agent to import the SVGs, call estimate_sheets for a lower bound, then nest with a 60-second budget and export per-sheet DXF. On the project's benchmark that kind of job used 56% of a sheet against 62% for the best competitor.
A maker-space technician preparing student jobs in LightBurn
Nest a mix of student files without redrawing them
Import the .lbrn2 project in the v0.2.0-alpha.1 preview; groups are nested as rigid units and an editable .lbrn2 comes back per sheet. Older text may need a native save first, per the docs.
A developer automating quoting for an online cutting service
Estimate sheet count and material per order before a human reviews it
Run nestbolt-mcp or the CLI headless with a repeatable work budget so the same order always prices the same; validate_layout confirms spacing and containment before the quote goes out.
Before you commit
- Setup
- Download the v0.1.0 or v0.2.0-alpha.1 archive for Windows x64, Linux x64 or macOS Apple silicon (or cargo build), then claude mcp add --transport stdio nestbolt -- /path/to/nestbolt-mcp. A Claude Code plugin and a Windows MCPB bundle for Claude Desktop are also provided.
- Integrations
- Five tools: import_parts (SVG, DXF or one LightBurn project), nest, validate_layout, export_layout (SVG, DXF or LBRN2) and estimate_sheets. The same engine runs in the browser app and the nestbolt CLI.
- Data and privacy
- Runs locally with no network, account or credentials. The server reads and writes only inside its working directory or NESTBOLT_WORKSPACE, refuses paths with .., and never overwrites files. No security advisories are published.
- Cost at scale
- Free. Compute is one CPU core per job; the benchmark's 451-letter showcase took 120 seconds on one core, and nest budgets cap at 300 seconds.
- Limits
- Very new: v1.1 plan 60% complete per the status page. Common-line cutting is under development, older LightBurn text and mixed groups need preparation, and Sparrow still wins some single-sheet jobs.
What’s good
- Published, reproducible benchmark including its losses
- Part-in-part nesting across several sheets and stock sizes
- Workspace sandbox and no-overwrite rule for agent use
- Repeatable layouts from the same inputs, budget and seed
What’s not
- Created October 2026; one author and about 11 stars
- No pip, npm or Homebrew install; binary or Cargo build
- Benchmarks are self-reported, not independent
- Common-line cutting and LightBurn import still in preview
Best for
Laser and CNC shops, and the agents that prepare their cut files, who want better material use than Deepnest without uploading drawings.
Nestbolt alternatives
Nestbolt: common questions
- Is Nestbolt worth it?
- Serious engineering and an honest benchmark make this the nesting engine to watch, but at three weeks old it is a project to trial on scrap before it touches a production job. We rate it 3.7 out of 5.
- How much does Nestbolt cost?
- Free and open source (MIT). No account, network or keys.
- What are the downsides of Nestbolt?
- Created October 2026; one author and about 11 stars; no pip, npm or Homebrew install; binary or Cargo build; benchmarks are self-reported, not independent; common-line cutting and LightBurn import still in preview.
- Who is Nestbolt best for?
- Laser and CNC shops, and the agents that prepare their cut files, who want better material use than Deepnest without uploading drawings.
- How much does Nestbolt cost for a team or in production?
- Free. Compute is one CPU core per job; the benchmark's 451-letter showcase took 120 seconds on one core, and nest budgets cap at 300 seconds.
- Is Nestbolt safe for company data?
- Runs locally with no network, account or credentials. The server reads and writes only inside its working directory or NESTBOLT_WORKSPACE, refuses paths with .., and never overwrites files. No security advisories are published.
- What are the best Nestbolt alternatives?
- The closest alternatives we have reviewed are OpenSCAD MCP and MCP for Blender.
Answers checked Oct 31, 2026.