[EIE] Add visualization tool

[lillythomas]

Summary

Add a MCP-compatible tool for building raster tile URLs from COG (Cloud Optimized GeoTIFF) items using the VEDA Raster API, enabling map visualization for the EIE agent.

What it does

• Converts COG item URLs into tile URL templates ({z}/{x}/{y}) suitable for web mapping applications
• Fetches render parameters (colormap, rescale, bidx) from STAC collection metadata when a collection_id is provided
• Returns tile URLs along with collection-level metadata (title, description, units, time_density) for frontend display

How it does this

1. Added VizTool class inheriting from BaseTool[VizInputSchema, VizOutputSchema]
2. Implemented async _arun() method that:
   • URL-encodes COG URLs and builds tile URL templates pointing to the VEDA Raster API
   • Fetches collection metadata from STAC API to extract renders.dashboard params
   • Appends render params (bidx, colormap_name, rescale) to tile URLs
3. Added configuration via VizToolConfig:
   • veda_stac_url: VEDA STAC API URL (from VEDA_STAC_URL env var)
   • veda_raster_url: VEDA Raster API URL (from VEDA_RASTER_URL env var)
   • timeout: HTTP timeout (default: 15s)

Files changed

• akd_ext/tools/eie/__init__.py — New module init with exports
• akd_ext/tools/eie/viz.py — New tool implementation
• akd_ext/tools/__init__.py — Added exports
• pyproject.toml — Added httpx dependency

Testing

import asyncio
from akd_ext.tools.eie.viz import VizTool, VizToolConfig, VizInputSchema, VizItem

async def test():
    config = VizToolConfig(
        veda_stac_url='https://openveda.cloud/api/stac',
        veda_raster_url='https://openveda.cloud/api/raster',
    )
    tool = VizTool(config=config)
    result = await tool._arun(VizInputSchema(
        items=[VizItem(
            url='s3://veda-data-store/no2-monthly/OMI_trno2_0.10x0.10_202112_Col3_V4.nc.tif',
            id='OMI_trno2_0.10x0.10_202112_Col3_V4.nc',
            datetime='2021-12-01T00:00:00Z'
        )],
        collection_id='no2-monthly'
    ))
    print(f"Title: {result.title}")
    print(f"Colormap: {result.colormap_name}")
    print(f"Rescale: {result.rescale}")
    print(f"Tile URL: {result.items[0]['tile_url']}")

asyncio.run(test())

Output:

Title: NO₂
Colormap: rdbu_r
Rescale: [0.0, 1.5e+16]
Tile URL: https://openveda.cloud/api/raster/cog/tiles/WebMercatorQuad/{z}/{x}/{y}.png?url=s3%3A%2F%2Fveda-data-store%2Fno2-monthly%2FOMI_trno2_0.10x0.10_202112_Col3_V4.nc.tif&bidx=1&colormap_name=rdbu_r&rescale=0,15000000000000000

Environment variables required:

• VEDA_STAC_URL — VEDA STAC API URL (e.g., https://openveda.cloud/api/stac)
• VEDA_RASTER_URL — VEDA Raster API URL (e.g., https://openveda.cloud/api/raster)