Viewfinder
by xirreal
Viewfinder is a Fabric utility for shader developers working with Iris, exposing its debugging tools as in-game commands and an MCP server.
What it does
Viewfinder gives Iris shader development a set of inspection tools that run inside the game. It starts automatically with the Minecraft client and runs a stateless Streamable HTTP MCP server, so external tools and AI agents can drive the commands. Commands are registered under viewfinder, and scripts can use them to inspect, test and automate shader workflows. The mod needs Fabric API and Iris Shaders, and it is licensed under the MIT License as open source.
Its tools cover reloads, profiling, textures, buffers and screenshots. Shader reloads can be triggered on demand, with compilation errors collected into a list. GPU timings are captured as hierarchical per-pass data over a fixed frame window, which avoids permanent query overhead. Pipeline programs can be inspected to see nested Iris passes and the uniforms, UBOs and SSBOs they link. Textures such as the main and alternate colortex buffers, depth, shadow, noise and custom textures can be exported, and shader storage buffer objects can be dumped to disk for analysis.
Key features
Shader reload error list
Reloads can be triggered on demand, and any compilation errors are gathered into a list.
On-demand GPU profiles
Per-pass timings are collected over a chosen frame window instead of running all the time.
Texture and buffer dumping
Colortex, depth, shadow, noise and custom textures, plus SSBO contents, can be exported to disk.
Interactive chat output
Paths to dumped files appear in chat, where a click opens or copies them, and error messages carry copy buttons that hold the complete message and stack trace.
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Required 2
Use cases
Scripted shader testing
Developers can call the MCP server from scripts to reload shaders, read errors and compare results between runs.
Scheduled screenshots
Screenshots can be taken after a configurable frame delay, useful for comparing shader output at fixed points.
Who it’s for: Shader pack authors and developers who work with Iris and want to inspect or automate their workflow, including through AI agents.
How it compares
Sakura Lava Vision is a Fabric client-side mod for 26.2 under the MIT License and is open source. Dimension Based Shader Switch is open source under the GNU General Public License v3.0 only and covers 1.21.11 – 26.2, switching shaders by dimension rather than debugging them. Viewfinder targets 26.1 – 26.3 and focuses on inspection and automation.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Viewfinder | Fabric | 26.1 – 26.3 | Client-side only | 2026-10-03 |
| Sakura Lava Vision | Fabric | 26.2 | Client-side only | 2026-07-27 |
| Dimension Based Shader Switch | Fabric | 1.21.11 – 26.2 | Client-side only | 2026-07-06 |
Questions
Does Viewfinder need Iris Shaders?
Which game versions does Viewfinder support?
Does the server need Viewfinder?
In the catalog
Viewfinder is one of 36,990 Utility mods on ModsFinder, and one of 25,772 Utility mods for Fabric. 8,071 mods support Minecraft 26.3.
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What the author says
A shader debugging mod for Iris on Fabric that exposes an MCP server and in-game commands for AI agents to inspect, test, and automate shader development workflows. Chat output uses clickable controls where Minecraft supports them: dumped file paths can be opened or copied, list output includes dump command…
Official listing
- Modrinth page
- modrinth.com/mod/viewfinder
- Owner
- xirreal
- Published
- 2026-03-26
- Updated on Modrinth
- 2026-10-03
- Facts verified
- 2026-10-15