Seiðr-Smiðja
hrabanazviking/Seidr-Smidja
Agent-only forge that builds, checks and renders VRM avatars through MCP, CLI or REST
Seiðr-Smiðja is a headless VRM avatar builder that AI agents drive through MCP, a command line, a REST API or skill manifests. It lets Hermes Agent, OpenClaw or Claude Code design and export avatars for VRChat and VTube Studio without a GUI.
What Seiðr-Smiðja does
Seiðr-Smiðja turns a YAML specification into a finished VRM avatar. An agent describes height, proportions, hair, outfit, expressions and license metadata. The forge loads a VRoid Studio base template, runs Blender headlessly to apply the changes, validates the result against VRChat and VTube Studio compliance rules, and returns the .vrm file with preview renders.
Renders cover front, three-quarter, side, face close-up, T-pose and signature expressions, so the calling agent can inspect its work, critique it and submit a revised spec. A failed compliance check returns a structured failure report rather than a silent pass. The forge is reached through four doors: MCP (Mjöll), a CLI (Rúnstafr), REST (Straumur), and skill manifests for Hermes, OpenClaw and Claude Code. A second mode, Brúarhönd, can drive a live VRoid Studio session on the same machine or on another machine over Tailscale. It is not a general 3D pipeline and handles only VRM avatars.
Key features
- YAML spec input covering height, proportions, hair, outfit, expressions and license metadata
- Headless Blender build from a VRoid Studio base template
- Compliance checks for VRChat and VTube Studio with structured failure reports
- Preview renders from several angles and expressions so the agent can critique its own output
- Four access paths: MCP, CLI, REST and skill manifests
- Brúarhönd mode for driving a VRoid Studio session across Tailscale
When to use it
- Letting a Hermes agent design a VTuber avatar and revise it from render feedback
- Producing VRChat-ready avatars from a script instead of a graphical editor
- Checking an avatar against VRChat and VTube Studio rules before using it
Who it is for: Developers and VTubers who want an AI agent to create VRM avatars for VRChat or VTube Studio.
How it fits with Hermes Agent
It supports Hermes Agent through skill manifests and the same MCP, CLI and REST interfaces it offers to OpenClaw and Claude Code.
Requirements: Blender run headlessly, the VRM Add-on for Blender, and a VRoid Studio base template; Brúarhönd needs VRoid Studio on the same machine or on one reachable over Tailscale
FAQ
What is Seiðr-Smiðja?
Seiðr-Smiðja is a headless, programmatic forge that lets AI agents design, build, render, critique and export VRM avatars. It is driven by a YAML spec rather than a graphical interface.
Does Seiðr-Smiðja work with Hermes Agent?
Yes, the README lists Hermes among the supported agents, alongside OpenClaw and Claude Code. Hermes can use it through the skill manifests, MCP, the CLI or the REST API.
Can a person use Seiðr-Smiðja through a graphical interface?
No, it has no clickable interface. A person can use it through the CLI or by writing a script.
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