# How an Agent Built a 3D Paris Gallery by Chaining Two Hugging Face Spaces > Source: > Published: 2026-06-09 10:46:19+00:00 πŸ‘ 192 #### TripoSplat Generate 3D Gaussian models from a single image I asked a coding agent to build a beautiful website showcasing the monuments of Paris as 3D Gaussian splats. I never opened an image generator. I never touched a 3D reconstruction tool. The agent produced every asset (the images **and** the 3D splats) by calling two Hugging Face Spaces directly, then wired them into a cinematic viewer. Here's the result, live as a static Space: This post is about *how* that's possible now, and why I think it's a preview of how a lot of multimedia software gets built from here on. Mitchell Hashimoto recently described a shift he calls the [building block economy](https://mitchellh.com/writing/building-block-economy): the most effective path to software is no longer a polished monolith, but small, well-documented components that others (increasingly *agents*) can assemble. His key observation: AI is okay at building everything from scratch, but it is **really good at gluing together** proven pieces. That thesis has mostly been told with *code* libraries. But the same forces are hitting **multimedia AI**. The hard part of using a state-of-the-art image model, a video model, a TTS model, or a 3D reconstruction model was never the model. It was the integration: SDKs, weights, GPUs, input formats, polling. If each model were instead a documented, callable block, an agent could glue them together the same way it globs together npm packages. That's exactly what Hugging Face Spaces have quietly become. `agents.md` The Hub hosts thousands of state-of-the-art models (a huge share of them **open-weights**), and most are deployed as interactive **Spaces**. As of now, every Gradio Space also exposes a plain-text [ agents.md](https://huggingface.co/docs/hub/en/spaces-agents) that tells an agent ``` curl https://huggingface.co/spaces/VAST-AI/TripoSplat/agents.md ``` returns everything needed in one shot: the schema URL, the call and poll templates, how to upload files, and the auth hint: ``` API schema: GET .../gradio_api/info Call endpoint: POST .../gradio_api/call/v2/{endpoint} {"param_name": value, ...} Poll result: GET .../gradio_api/call/{endpoint}/{event_id} File inputs: POST .../gradio_api/upload -F "files=@file.ext" Auth: Bearer $HF_TOKEN ``` No client library. No hardcoded integration. An agent reads that, and it can drive the Space end to end. Set an [ HF_TOKEN](https://huggingface.co/settings/tokens) and you're going. You can find these instructions on any Gradio Space via its The real unlock is **chaining**: the output of one Space becomes the input to the next. Prompt β†’ image β†’ 3D. That's the whole pipeline behind this gallery. The agent chained two Spaces: `VAST-AI/TripoSplat` `.ply` ) from each single image. Image in, 3D out.Generated image Reconstructed splat The six source images the agent generated, all isolated on black, ready for single-image 3D reconstruction: From there the agent did the "glue" work too. It noticed TripoSplat outputs are Y-down and flipped them upright, auto-framed each monument, compressed the `.ply` files to `.ksplat` (~3Γ— smaller, so they load fast), built a Three.js viewer with a scroll-to-switch and drag-to-rotate UI, and deployed the whole thing as a static Space. The only human inputs were taste-level: "make it zoomed out," "replace the obelisk with something better for splatting," "the transition lingers too long." Several of those steps were **the agent reacting to reality**. A wide glass pyramid splats poorly. A thin obelisk is dull. A single-view reconstruction infers the back. That is exactly the "outsourced R&D, fast iteration" loop the building-block economy predicts, except the R&D was a conversation. The real test of a building block is how cheaply you can reuse it. Once this pipeline existed, spinning up entirely new galleries cost about one sentence each. "Create a similar Space with splats for Japan," then the same for Egypt, and the agent did the rest: six monument images, six splats, compression, a viewer, and a deployed Space, per country.