pp-stac

STAC — Printing Press CLI

Prerequisites: Install the CLI

This skill drives the stac-pp-cli binary. You must verify the CLI is installed before invoking any command from this skill. If it is missing, install it first:

Install via the Printing Press installer. It defaults binaries to $HOME/.local/bin on macOS/Linux and %LOCALAPPDATA%\Programs\PrintingPress\bin on Windows:
```
npx -y @mvanhorn/printing-press-library install stac --cli-only
```
Verify: stac-pp-cli --version
Ensure the reported install directory is on $PATH for the agent/runtime that will invoke this skill.

If the npx install fails (no Node, offline, etc.), fall back to a direct Go install (requires Go 1.26.6 or newer). This installs into $GOPATH/bin (default $HOME/go/bin), so add that directory to $PATH instead:

go install github.com/mvanhorn/printing-press-library/library/maps/stac/cmd/stac-pp-cli@latest

If --version reports "command not found" after install, the runtime cannot see the binary directory on $PATH. Do not proceed with skill commands until verification succeeds.

stac-pp-cli searches any STAC API (default: AWS Earth Search) for satellite imagery with full bbox/datetime/intersects/cloud-cover filtering, then goes beyond every existing tool: a local SQLite cache powers offline search, coverage, timeline, gaps, and watch; scenes best ranks for the clearest image with a client-side fallback; and assets resolves provider-aware band download URLs. Agent-native by default with --json, --select, and a typed MCP surface.

When to Use This CLI

Use stac-pp-cli when an agent or analyst needs to discover satellite imagery (Sentinel-2, Landsat, Sentinel-1, NAIP, Copernicus DEM) from a STAC API, pick the clearest scene over an area, check temporal coverage, or resolve band download URLs. It is ideal for scripting EO discovery and for agent workflows that need bounded, structured output instead of verbose GeoJSON.

Anti-triggers

Do not use this CLI for:

Downloading or reprojecting the actual raster pixels (use rasterio, gdal, or stackstac/odc-stac after resolving URLs with 'assets')
Authoring or validating static STAC catalogs (use stactools or go-stac)
Tiling or rendering imagery for a web map (use titiler)

Unique Capabilities

These capabilities aren't available in any other tool for this API.

Scene selection

scenes best — Pick the single clearest scene over an area and date range.

Reach for this when an agent needs the one best image for an AOI, not a list to sift through.
```
stac-pp-cli scenes best --collection sentinel-2-l2a --bbox -122.5,37.7,-122.3,37.9 --datetime 2024-06-01/2024-06-30 --agent
```
clouds — Show the cloud-cover distribution over an area and date range.

Use before downloading to judge how cloudy a window is without pulling any imagery.
```
stac-pp-cli clouds --collection sentinel-2-l2a --bbox -122.5,37.7,-122.3,37.9 --datetime 2024-06-01/2024-08-31 --agent
```

Coverage and time

coverage — Answer whether data exists over an area and when, with a temporal summary.

Reach for this to confirm an AOI has usable data before planning an analysis.
```
stac-pp-cli coverage --collection landsat-c2-l2 --bbox -122.5,37.7,-122.3,37.9 --datetime 2023-01-01/2024-12-31 --agent
```

timeline — Build a per-date time series of scenes for change detection.

Use to assemble a clean observation series for NDVI or change detection.

stac-pp-cli timeline --collection sentinel-2-l2a --bbox -122.5,37.7,-122.3,37.9 --datetime 2024-01-01/2024-06-30 --max-cloud 30 --agent

gaps — Find missing acquisition windows over an area versus expected revisit.

Reach for this to spot coverage holes before relying on a time series.
```
stac-pp-cli gaps --collection sentinel-2-l2a --bbox -122.5,37.7,-122.3,37.9 --datetime 2024-01-01/2024-06-30 --revisit-days 5 --agent
```
watch — Report scenes published over an area since the last check.

Use to monitor an AOI for fresh imagery across runs.
```
stac-pp-cli watch --collection sentinel-2-l2a --bbox -122.5,37.7,-122.3,37.9 --agent
```

Assets and analysis

assets — Resolve an item's band and asset download URLs, provider-aware.

Reach for this to get ready-to-download band URLs without parsing the raw item JSON.
```
stac-pp-cli assets S2A_10SEG_20240622_0_L2A --collection sentinel-2-l2a --bands red,green,blue,nir --agent
```
compare — Compare two collections over the same area and date range.

Use to choose between sensors (e.g. Sentinel-2 vs Landsat) for an AOI.
```
stac-pp-cli compare sentinel-2-l2a landsat-c2-l2 --bbox -122.5,37.7,-122.3,37.9 --datetime 2024-01-01/2024-06-30 --agent
```
stack-snippet — Emit a ready-to-paste stackstac/odc-stac Python snippet for matched scenes.

Reach for this to jump from scene discovery straight into an xarray workflow.
```
stac-pp-cli stack-snippet --collection sentinel-2-l2a --bbox -122.5,37.7,-122.3,37.9 --datetime 2024-06-01/2024-06-30 --bands red,green,blue,nir
```

Command Reference

aggregate — Manage aggregate

stac-pp-cli aggregate — Executes one or more aggregations (e.g.

aggregations — Manage aggregations

stac-pp-cli aggregations get — Lists the aggregations available across the catalog (e.g. total_count, datetime_frequency, cloud_cover_frequency).

collections — All endpoints related to STAC API - Collections

stac-pp-cli collections describe — A single Feature Collection for the given if collectionId.
stac-pp-cli collections get — A body of Feature Collections that belong or are used together with additional links.

conformance — Manage conformance

stac-pp-cli conformance — A list of all conformance classes specified in a standard that the server conforms to.

items — Manage items

stac-pp-cli items get-search — Retrieve Items matching filters. Intended as a shorthand API for simple queries. This method is required to implement.
stac-pp-cli items post-search — Retrieve items matching filters. Intended as the standard, full-featured query API.

queryables — Manage queryables

stac-pp-cli queryables get — Returns the set of queryable properties (JSON Schema) usable in query/filter across the whole catalog.

Finding the right command

When you know what you want to do but not which command does it, ask the CLI directly:

stac-pp-cli which "<capability in your own words>"

which resolves a natural-language capability query to the best matching command from this CLI's curated feature index. Exit code 0 means at least one match; exit code 2 means no confident match — fall back to --help or use a narrower query.

Recipes

Clearest scene this season

stac-pp-cli scenes best --collection sentinel-2-l2a --bbox -122.5,37.7,-122.3,37.9 --datetime 2024-06-01/2024-09-30

Ranks scenes by cloud cover and returns the single best one with its band URLs.

Trim a verbose search for an agent

stac-pp-cli items get-search --collections sentinel-2-l2a --bbox -122.5,37.7,-122.3,37.9 --datetime 2024-06-01/2024-06-30 --agent --select 'features.id,features.properties.eo:cloud_cover,features.properties.datetime'

Pairs --agent with --select dotted paths to return only id, cloud cover, and datetime from the deeply nested item response.

Is there any data here?

stac-pp-cli coverage --collection sentinel-2-l2a --bbox 2.2,48.8,2.4,48.9 --datetime 2024-01-01/2024-12-31

Returns the matched count and temporal min/max/frequency so you know if an AOI is worth analyzing.

Build a clean time series

stac-pp-cli timeline --collection sentinel-2-l2a --bbox -122.5,37.7,-122.3,37.9 --datetime 2024-01-01/2024-06-30 --max-cloud 30

One low-cloud observation per date, deduped by orbit and tile, ready for change detection.

Get band download URLs

stac-pp-cli assets S2A_10SEG_20240622_0_L2A --collection sentinel-2-l2a --bands red,green,blue,nir

Resolves the cloud-optimized GeoTIFF URLs for the requested bands.

Auth Setup

No authentication required.

Run stac-pp-cli doctor to verify setup.

Agent Mode

Add --agent to any command. Expands to: --json --compact --no-input --no-color --yes.

Pipeable — JSON on stdout, errors on stderr
Filterable — --select keeps a subset of fields. Dotted paths descend into nested structures; arrays traverse element-wise. Critical for keeping context small on verbose APIs:
```
stac-pp-cli aggregate --agent --select id,name,status
```
Previewable — --dry-run shows the request without sending
Offline-friendly — sync/search commands can use the local SQLite store when available
Non-interactive — never prompts, every input is a flag
Explicit retries — use --idempotent only when an already-existing create should count as success

Response envelope

Commands that read from the local store or the API wrap output in a provenance envelope:

{
  "meta": {"source": "live" | "local", "synced_at": "...", "reason": "..."},
  "results": <data>
}

Parse .results for data and .meta.source to know whether it's live or local. A human-readable N results (live) summary is printed to stderr only when stdout is a terminal AND no machine-format flag (--json, --csv, --compact, --quiet, --plain, --select) is set — piped/agent consumers and explicit-format runs get pure JSON on stdout.

Paths and state

Agents should treat the CLI's path resolver as part of the runtime contract:

Use --home <dir> for one invocation, or set STAC_HOME=<dir> to relocate all four path kinds under one root.
Use per-kind env vars only when a specific kind must diverge: STAC_CONFIG_DIR, STAC_DATA_DIR, STAC_STATE_DIR, STAC_CACHE_DIR.
Resolution order is per-kind env var, --home, STAC_HOME, XDG (XDG_CONFIG_HOME, XDG_DATA_HOME, XDG_STATE_HOME, XDG_CACHE_HOME), then platform defaults.
config contains settings like config.toml and profiles. data contains credentials.toml, data.db, cookies, and auth sidecars. state contains persisted queries, jobs, and teach.log. cache contains regenerable HTTP/cache files.
Stored secrets live in credentials.toml under the data dir. Existing legacy config.toml secrets are read for compatibility and leave config.toml on the first auth write.
Run stac-pp-cli doctor --fail-on warn to surface path and credential-location warnings. agent-context exposes a schema v4 paths block for agents that need the resolved dirs.

For MCP, pass relocation through the MCP host config. The MCP binary does not inherit CLI flags:

{
  "mcpServers": {
    "stac": {
      "command": "stac-pp-mcp",
      "env": {
        "STAC_HOME": "/srv/stac"
      }
    }
  }
}

Fleet precedence: an inherited per-kind env var overrides an explicit --home for that kind. Use STAC_HOME or per-kind vars as durable fleet levers, and use --home only for a single invocation. Relocation is not reversible by unsetting env vars; move files manually before clearing STAC_HOME, or doctor will not find credentials left under the former root.

Agent Feedback

When you (or the agent) notice something off about this CLI, record it:

stac-pp-cli feedback "the --since flag is inclusive but docs say exclusive"
stac-pp-cli feedback --stdin < notes.txt
stac-pp-cli feedback list --json --limit 10

Entries are stored locally as feedback.jsonl under the resolved data dir. They are never POSTed unless STAC_FEEDBACK_ENDPOINT is set AND either --send is passed or STAC_FEEDBACK_AUTO_SEND=true. Default behavior is local-only.

Write what surprised you, not a bug report. Short, specific, one line: that is the part that compounds.

Output Delivery

Every command accepts --deliver <sink>. The output goes to the named sink in addition to (or instead of) stdout, so agents can route command results without hand-piping. Three sinks are supported:

Sink	Effect
`stdout`	Default; write to stdout only
`file:<path>`	Atomically write output to `<path>` (tmp + rename)
`webhook:<url>`	POST the output body to the URL (`application/json` or `application/x-ndjson` when `--compact`)

Unknown schemes are refused with a structured error naming the supported set. Webhook failures return non-zero and log the URL + HTTP status on stderr.

Named Profiles

A profile is a saved set of flag values, reused across invocations. Use it when a scheduled agent calls the same command every run with the same configuration - HeyGen's "Beacon" pattern.

stac-pp-cli profile save briefing --json
stac-pp-cli --profile briefing aggregate
stac-pp-cli profile list --json
stac-pp-cli profile show briefing
stac-pp-cli profile delete briefing --yes

Explicit flags always win over profile values; profile values win over defaults. agent-context lists all available profiles under available_profiles so introspecting agents discover them at runtime.

Exit Codes

Code	Meaning
0	Success
2	Usage error (wrong arguments)
3	Resource not found
5	API error (upstream issue)
7	Rate limited (wait and retry)
10	Config error

Argument Parsing

Parse $ARGUMENTS:

Empty, help, or --help → show stac-pp-cli --help output
Starts with install → ends with mcp → MCP installation; otherwise → see Prerequisites above
Anything else → Direct Use (execute as CLI command with --agent)

MCP Server Installation

Install the MCP server:

go install github.com/mvanhorn/printing-press-library/library/maps/stac/cmd/stac-pp-mcp@latest

claude mcp add stac-pp-mcp -- stac-pp-mcp

Verify: claude mcp list

Direct Use

Check if installed: which stac-pp-cli If not found, offer to install (see Prerequisites at the top of this skill).
Match the user query to the best command from the Unique Capabilities and Command Reference above.

Execute with the --agent flag:

stac-pp-cli <command> [subcommand] [args] --agent

If ambiguous, drill into subcommand help: stac-pp-cli <command> --help.