| name | geemu-skill |
| description | Use when Codex needs to answer questions or write Python code for Google Earth Engine (GEE), the Earth Engine Python API, geemap, ee.Image/ImageCollection/FeatureCollection workflows, remote-sensing scripts, exports, reducers, cloud masking, dataset lookup, or Liu Zhao's local GEE/geemap knowledge and practical experience. |
GEEMu Skill
Use this skill to write practical Google Earth Engine and geemap workflows from
the bundled GEEMu references and local vector knowledge base.
Start Here: Project ID First, Then Verify
The first action in every GEEMu task — before retrieval, research design, or any
code — is to establish the Cloud Project ID and verify the environment, in order:
- Ask the user for their Earth Engine Cloud Project ID if it was not already
given. Do not guess it and do not continue without it; every online Earth
Engine call needs
Initialize(project=...). (Tip: the user can set
EE_PROJECT once to avoid re-entering it each session.)
- Verify the environment with that Project ID: confirm
ee and geemap
import, Earth Engine credentials exist, and
geemap.ee_initialize(project="<PROJECT_ID>") (or
ee.Initialize(project="<PROJECT_ID>")) succeeds. The deterministic check is
python scripts/check_local_environment.py --project <PROJECT_ID>.
- Only after the Project ID is confirmed and initialization succeeds, continue
to retrieval, research design, and code.
If verification fails, diagnose in this order: (1) restricted network — check
the HTTP_PROXY / HTTPS_PROXY environment variables first, since blocked
Google connectivity is the most common cause (see references/network_proxy.md);
(2) missing credentials → run earthengine authenticate; (3) other errors → see
references/local_environment.md. Resolve this before writing task code.
Included Knowledge
gee_vector_db/: portable local knowledge database derived from the full
GEEMu bundle and practical experience notes.
awesome-gee-community-datasets/community_datasets.csv: structured community
dataset index.
references/: GEEMu workflow gates for environment, proxy, research design,
data semantics, boundaries, local vectors, and compute strategy.
templates/: run-log and data-layer templates.
examples/: compact runnable examples.
This compact full GitHub package keeps the complete usable GEEMu workflow through
the bundled local knowledge DB, references, examples, and community CSV. It does
not carry the redundant raw google-earth-engine/ or geemap/ documentation
snapshots. Search is keyword-based and does not require an embedding model
download. Prefer the bundled local knowledge DB first; use source URLs or
official online docs when a direct API detail must be verified.
Retrieval Workflow
For non-trivial questions, search local knowledge before answering or coding:
python _gee_vector_db.py search "<query>" --db gee_vector_db --limit 8
For community dataset lookup:
rg -n "<term>" awesome-gee-community-datasets/community_datasets.csv
Prefer evidence in this order:
- Official Earth Engine behavior found in vector hits or source URLs.
- geemap usage patterns found in vector hits or examples.
- Liu Zhao's local practical experience represented in the knowledge DB.
- Community dataset catalog rows, after checking license and docs links.
Required Gates
Before writing final code, run the relevant gates:
- Startup gate: open
references/local_environment.md; confirm Python can import
ee and geemap, Earth Engine credentials exist, a Cloud Project ID is known,
and online initialization succeeds. If the Project ID is missing, stop and ask.
- Network/proxy: for restricted networks, open
references/network_proxy.md.
- Research design: for open-ended tasks, open
references/research_design.md;
decide study area, analysis scale/resolution, and output target. Use local
knowledge to suggest options when the user has not specified them.
- Local vector ROI: for shapefile, GeoJSON, GeoPackage, or GeoDataFrame inputs,
open
references/local_vector_roi.md.
- Data semantics: for dataset choice, bands, units, scale/offset, QA masks, or
transformations, open
references/data_layer.md.
- Boundary and compute: for ROI complexity, bbox, clipping, tiling, exports,
memory, or EECU risk, open
references/boundary_compute.md.
- Traceability: save generated scripts and Markdown logs under
runs/YYYYMMDD-HHMM-task-name/.
Ask clarifying questions when missing information changes correctness, cost,
network access, or data meaning. If a missing value is routine, use an explicit
placeholder and record the assumption.
Confirm Before Running
Before running a task or executing final code against Earth Engine, restate the
key choices and ask the user to confirm or adjust them. Earth Engine runs cost
compute, and resolution / region / output choices are easy to get wrong, so a
short confirmation prevents wasted runs, surprise costs, and files landing in the
wrong place.
Confirm at least:
- Output target: local GeoTIFF download (where on disk?), Google Drive export,
Earth Engine Asset, map preview only, or a numeric/CSV summary. Each is a
different code path and cost profile, so always confirm which one.
- Analysis scale / resolution: the compute and export scale in meters, and
whether it is the dataset's native resolution or a coarser test scale.
- Study area / ROI and time range.
- Dataset and key transforms (bands, masks, thresholds) when not already fixed.
- Cost / size risk: region extent, pixel count, number of tiles or export tasks.
Present this as a short, concrete summary (a few lines or a small table) with
sensible defaults drawn from local knowledge, so the user can confirm in one
step. Do not re-ask values the user already gave. Use the research-design gate to
derive the options, then confirm them here.
Run the workflow only after the choices are confirmed. Pair this with the export
guardrails below: show the resolved plan with --dry-run, get confirmation, then
run with --export for any task that writes data or starts a batch job.
Output Artifacts
Every generated or revised GEE/geemap task should save:
runs/YYYYMMDD-HHMM-task-name/
code.py
RUN.md
DATA_LAYER.md
sources.md
Use templates/RUN.md and templates/DATA_LAYER.md as starting points. Do not
overwrite old run folders.
Coding Rules
-
Write Python-first GEE code unless the user explicitly asks for JavaScript.
-
Use explicit import ee and import geemap in runnable Python scripts.
-
The saved script is named code.py, which shadows Python's standard-library
code module that geemap loads through ipywidgets/IPython. Before importing
geemap, drop the script directory from sys.path[0] so the stdlib module wins;
otherwise import geemap crashes with
AttributeError: module 'code' has no attribute 'InteractiveConsole':
import sys
from pathlib import Path
if sys.path and Path(sys.path[0]).resolve() == Path(__file__).resolve().parent:
sys.path.pop(0)
import ee
import geemap
-
Initialize with geemap.ee_initialize(project="PROJECT_ID") or an equivalent
ee.Initialize(project="PROJECT_ID") check before building ROI,
ImageCollection, reducers, exports, or maps.
-
Do not hard-code private project IDs, asset IDs, local paths, proxy
credentials, tokens, or cookies. Use placeholders like PROJECT_ID,
ROI_ASSET, TILE_ASSET, and EXPORT_FOLDER.
-
For administrative boundaries use FAO/GAUL/2015/level0|1|2 (filter on
ADM0_NAME / ADM1_NAME / ADM2_NAME); GADM is not a public GEE asset. Names
are romanized, e.g. China ADM1_NAME="Sichuan Sheng" — verify the exact string
before relying on it. See references/research_design.md.
-
If local vector data is provided, prefer geemap.shp_to_ee,
geemap.geojson_to_ee, or geemap.gdf_to_ee after checking CRS, geometry
type, and feature count.
-
Keep heavy work server-side with Earth Engine objects. Avoid .getInfo() on
large objects.
-
Prefer filterDate, filterBounds, select, map, reducers, and exports
over client-side loops.
-
For exports, include scale, region, crs, and destination. Make exports
opt-in: provide a --dry-run mode that prints the resolved parameters with no
Earth Engine call, and only call task.start() when the user passes
--export. Never auto-start an export on a plain run.
-
Before exporting a multi-band image, cast every band to one dtype, e.g.
image.toFloat(). Otherwise Earth Engine rejects the task with
Exported bands must have compatible data types; found inconsistent types: Float32 and Byte. This happens whenever a float index band (NBR, dNBR, NDVI,
recovery ratio) is combined with a Byte mask or class band produced by
.gte(...), .selfMask(), or .toByte(). Cast at export time, or export the
integer/categorical products in a separate task that keeps their Byte dtype.
-
For direct local GeoTIFF downloads, use geemap.download_ee_image only after
checking that the region is small or controlled. Set scale, region,
categorical/continuous dtype, resampling, and local output path deliberately.
For large or complex ROIs, prefer Drive export, Asset export, or tiled export.
-
Verify dataset IDs, band names, units, valid ranges, scale factors, offsets,
nodata/mask values, QA bit rules, and dtype before numeric transformations.
-
If a workflow may exceed Earth Engine limits, provide a tiled, batched, or
intermediate-Asset pattern.
Output Style
- Give complete runnable code with a short note about placeholders.
- Mention local file paths or source URLs when citing retrieved evidence.
- If local retrieval finds no direct support, say so and proceed from general
Earth Engine/geemap knowledge or official online docs.