The orchestration layer for AI‑assisted software development.
Works with everything. Needs nothing.
Every AI coding tool decides your context for you, then hides it. Fusion puts the assembled payload on screen and lets you edit it before a single byte leaves your machine. Then it applies the answer as one reversible transaction.
Windows · 30 days, fully functional. No registration. No credit card.
Why a new layer needs to exist
The AI coding stack fails developers in four specific ways.
Context fragmentation
Your IDE silently injects what it assumes you need. You cannot see it. You cannot edit it. Tokens are spent before your prompt is even sent.
No prompt discipline
Every interaction starts from scratch. Reuse, organisation and searchability are absent from the tooling. The careful prompt you wrote last week is gone the moment the session ends.
Provider lock-in
Switching models means switching tools. Comparing Claude against GPT against a local model means three products, three prompts, three workflows.
No safety-first version control
AI changes simply happen. Preview, atomic apply and one-click rollback independent of Git are missing. A bad suggestion becomes a debugging session.
Positioning
Fusion in three words.
Granularity
Context is visible, editable and controllable before send. You decide what the model sees, file by file.
Flexibility
Providers, models and workflows are interchangeable by design. Bring your own keys; point any provider at your own endpoint.
Safety
AI-applied changes are previewed, atomic and reversible — with a version store that does not depend on Git.
01 · Project intelligence
No competitor shows you the full prompt. None of them let you edit it.
Fusion assembles every prompt as a transparent payload: an ASCII project tree marking exactly which files were selected, followed by their full contents. It is shown to you before send, and you can change any of it.
Context is the substrate of everything.
Precision context is the difference between a useful answer and a confident wrong one. Fusion gives you the controls to build it deliberately instead of hoping an IDE guessed correctly.
- Tree selection snapshots — save a curated file selection per task and reload it instantly.
- AI dependency resolution — detect imports, class instantiations, interface implementations, inheritance and cross-file references, then pull them in.
- Project rules — permanently exclude build folders, vendor code and noise so they never reach a prompt.
- Compression — reduce payload size when the context window is tight.
- Relative paths only — the payload references
<Project Root>, so nothing about your machine goes out.
02 · AI Live Debug
Preview first. Apply atomically. Roll back without Git.
Write the instruction in plain English. Fusion sends a compact, precise payload, and the model comes back with a change set — which you read in full before anything touches disk.
The undo that does not need a clean working tree.
Every applied run becomes a version. The chain is per-project, persistent, and reaches back to a baseline captured before the first AI edit. You can name the ones worth keeping.
Competing tools rewind through Git or through session memory. Fusion works on uncommitted code, dirty trees, codebases with no version control at all, and non-code files — configs, docs, data, schemas.
An industry first
Air-gapped Service Mode.
Optionally, Fusion assembles the payload locally and hands it to you instead of to a network. Paste it into any chat interface — or any model on an isolated network — and paste the answer back. It re-enters through the same preview-and-apply gate.
For the environments that cannot ship code to a third party.
Defence, finance, healthcare and regulated public sector teams are not allowed to send source code to a vendor API. Every AI coding tool built as a service is unavailable to them by policy, not by preference.
The same mechanism handles a more ordinary problem: hitting a vendor's rate limit or tier ceiling. Service Mode routes around it. Same precision payload, no queue, no upgrade.
- No API call — the payload is generated on your machine and copied to the clipboard.
- Any destination — a web chat, an enterprise assistant, or a model on an air-gapped network.
- Same safety path — the response is validated, previewed and applied atomically, and remains reversible.
03 · Visual flow editor
Compose multi-model pipelines on a canvas.
Flow is a real execution engine. Nodes run as soon as their inputs are ready, independent branches run concurrently, and every node reports its own status and timing as the graph executes.
Models
Text, image and vision nodes. Mix GPT, Claude, Gemini, Grok and local Ollama models freely inside a single graph.
Inputs and branching
Text input parameters, file load and save, file operations, and conditional branching.
APIs and webhooks
HTTP requests with templated URLs, headers and bodies; JSON extraction by path; Slack, Discord and Teams notifications.
Transform and merge
Line-by-line loops, regex replace, fan-out and fan-in merge, delays, image resize, format conversion and background removal.
Or describe it and let Fusion build the graph.
Type what the pipeline should do in plain English. The wizard designs the node graph, wires it, and hands it back on the canvas — where you can inspect every property and change anything before you run it.
Generated flows are ordinary flow files. Save them, version them, share them with your team, or run them headlessly on a schedule.
Headless
Same engine, no window.
Every flow runs from the command line. Parameterise it, batch it over a CSV, or emit machine-readable JSON — which makes Fusion addressable from CI, schedulers and build scripts.
Parameters and batch
Inject values into a saved flow, or run it once per row of a CSV with outputs written to a folder per row.
Validate and dry run
Static-check a graph, or print the resolved plan with secrets masked, before anything executes.
Secrets by reference
Tokens resolve from the environment at run time, so keys never live inside the flow file you commit or share.
04 & 05
Also in the box.
Prompt engineering
Prompts stop being throwaway text. Keep a managed library of reusable pre-prompts scoped per project type or universal, search across them by title and body, pin the ones you reach for daily, and inject common instruction patterns with a single click. Dynamic variables such as project root and date expand automatically at generation time, and every prompt Fusion generates is logged with a timestamp.
Application wizard
Describe an application and Fusion scaffolds a complete, runnable project on disk, then registers it in your project tree. Attach an existing codebase as a reference so the output follows your structure and conventions, and attach a written blueprint to encode your engineering standards and business rules. Generate with AI, or hand the payload to any external tool through Service Mode.
Competitive landscape
Fusion orchestrates across the stack. Each incumbent solves a slice of it.
Complementary, not displacive. A developer running Cursor and Copilot and Claude Code still has no way to see the payload, no way to switch providers without switching tools, and no way to undo an AI edit that Git never saw.
| Capability | Cursor | Copilot | Claude Code | Codex | Fusion |
|---|---|---|---|---|---|
| Editor-independent | — | plugin | Yes | Yes | Yes |
| Provider freedom, bring your own key | curated | curated | Anthropic only | OpenAI default | Yes |
| Inline editor autocomplete | Yes | Yes | — | — | — |
| Visible and editable prompt pre-send | — | — | file ops only | file ops only | Yes |
| Visual flow editor | — | — | — | — | Yes |
| Reference projects and blueprints | — | — | — | partial | Yes |
| Air-gapped service mode | — | — | — | — | Yes |
| Atomic apply across multiple files | — | — | — | — | Yes |
| Git-independent rollback | — | — | session-scoped | — | Yes |
Comparison reflects publicly documented capabilities as of mid-2026. Cursor bring-your-own-key is Pro-tier only. Claude Code rewinds within session memory. Fusion does not attempt inline autocomplete — that is what your editor is already good at.
Get Fusion
Production-ready. Feature-complete. Shipping today.
Fusion is a native desktop application — which is what makes local payload generation and air-gapped operation possible in the first place.
Windows (macOS and Linux soon) · v2.5 installer, 2.8 MB · 30-day fully functional trial · no registration, no credit card.
Questions, or want a walkthrough? Contact Arun — [email protected]