# Umbra open SAR archive (remote · api.umbra-py.space)

Search, preview, and measure Umbra open SAR from any MCP client. Umbra ships no search API.

- Trust score: 64/100 (medium)
- Change this week: +2
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- remote · `api.umbra-py.space`: 64/100 (this document), [markdown](https://verifymcp.io/servers/reesehammer-umbra-mcp/api.md), [page](https://verifymcp.io/servers/reesehammer-umbra-mcp/api)
- pypi · `umbra-py`: 35/100, [markdown](https://verifymcp.io/servers/reesehammer-umbra-mcp/umbra-py.md), [page](https://verifymcp.io/servers/reesehammer-umbra-mcp/umbra-py)

## Channel facts

- Endpoint: `https://api.umbra-py.space/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `0.1.4`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-11-05.

- **Endpoint Security**: 11/100
  - TLS not yet verified: we couldn't open a connection to check the certificate.
  - Authorisation not yet verified: we couldn't confirm whether this endpoint requires it.
  - HTTPS is enforced; there's no plaintext access path.
  - HSTS not yet verified: we couldn't read the response headers to check for it.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 0/100
  - Transport check failed: declared streamable-http, but we couldn't connect to verify it.
- **Schema Quality & AI Usability**: 0/100
  - Schema not yet verified: we couldn't read the endpoint's schema, or could read only part of its tool list.
- **Stability & Change Management**: 0/100
  - Stability not yet verified: not enough scan history yet (needs a 30-day window).
- **Tool Coverage**: 0/100
  - Tool coverage not yet verified: we couldn't read the endpoint's tools, or could read only part of the list.
- **Tool Safety**: 0/100
  - Tool safety not yet verified: we couldn't read the endpoint's tools, or could read only part of the list.
- **Capabilities**: 0/100
  - Capabilities not yet verified: we couldn't read the endpoint's capabilities.

**Unverified: 5 categories.** Categories scored 0 because we could not verify them: authentication we do not have, an unreachable endpoint, or not enough scan history. We only credit what we can confirm.

## Install

### How do I install the Umbra open SAR archive MCP server?

Umbra open SAR archive is a hosted endpoint at https://api.umbra-py.space/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http reesehammer-umbra-mcp 'https://api.umbra-py.space/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "reesehammer-umbra-mcp": {
      "url": "https://api.umbra-py.space/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "reesehammer-umbra-mcp": {
      "type": "http",
      "url": "https://api.umbra-py.space/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.reesehammer-umbra-mcp]
url = "https://api.umbra-py.space/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "reesehammer-umbra-mcp": {
      "type": "remote",
      "url": "https://api.umbra-py.space/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add reesehammer-umbra-mcp --url 'https://api.umbra-py.space/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  reesehammer-umbra-mcp:
    url: "https://api.umbra-py.space/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "reesehammer-umbra-mcp": {
      "Transport": "http",
      "Url": "https://api.umbra-py.space/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add reesehammer-umbra-mcp -t streamable-http -u 'https://api.umbra-py.space/mcp'
```

### Other

```json
{
  "mcpServers": {
    "reesehammer-umbra-mcp": {
      "type": "http",
      "url": "https://api.umbra-py.space/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-11-04 (score 64, 0)

- [security regression] Endpoint reachability: reachable → unreachable
- [security regression] TLS certificate: pass → unverified
- [security regression] HSTS header: fail → unverified
- [security regression] Stability: 0.27 → unverified
- [security regression] Tool safety: pass → unverified
- [security regression] Transport: pass → fail
- [security] Authorization: Authorisation not yet verified: we couldn't confirm whether this endpoint requires it.
- [functional regression] Schema quality: 100 → unverified
- [functional regression] Capabilities: pass → unverified
- [functional regression] Tool coverage: 100 → unverified

### 2026-11-03 (score 64, +1)

No change was recorded against any check on this day. Stability & Change Management went from 23 to 27. That category is still filling its 30-day observation window: 7 days of observed history at the previous scan, 8 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-31 (score 63, +1)

No change was recorded against any check on this day. Stability & Change Management went from 13 to 17. That category is still filling its 30-day observation window: 4 days of observed history at the previous scan, 5 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-30 (score 62, 0)

- [security] Tool “get_item” rewrote its description, which is the text the model reads
- [security] Tool “download_asset” rewrote its description, which is the text the model reads

### 2026-10-29 (score 62, +1)

No change was recorded against any check on this day. Stability & Change Management went from 7 to 10. That category is still filling its 30-day observation window: 2 days of observed history at the previous scan, 3 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-27 (score 61, +1)

- [functional improvement] Stability: unverified → 0.03

### 2026-10-26 (score 60)

First indexed and scored.

## MCP tools (19)

### `search_catalog` (~1094 tokens)

Search Umbra's catalog and return compact context cards.

    Filters (all optional, combine freely): ``bbox`` as
    ``[min_lon, min_lat, max_lon, max_lat]`` in WGS84 degrees; ``intersects`` as
    a GeoJSON polygon object (a ``Polygon`` / ``MultiPolygon`` geometry, or a
    ``Feature`` / ``FeatureCollection`` wrapping one) to keep only footprints
    intersecting it -- a tighter spatial filter than the rectangular ``bbox``,
    and mutually exclusive with ``bbox`` / ``place``; ``place`` as a
    free-text name geocoded to a bbox; ``area`` as a substring of the Umbra
    task (site) name (set ``fuzzy`` to match it loosely -- word-order- and
    punctuation-independent and typo-tolerant, resolved deterministically with
    no model call, so ``"beet piler"`` still reaches ``"Beet Piler - ND"`` and
    ``"utah centerfield"`` still reaches ``"Centerfield,
    Utah"``; set ``semantic`` instead to treat ``area`` as a plain-language
    *description* of a site whose name you don't know and resolve it to the
    closest task names by *meaning* via the prebuilt embedding index, so
    ``"grain storage north dakota"`` reaches ``"Beet Piler - ND"`` -- a query
    that shares no word with the label, which ``fuzzy`` cannot and should not
    fake; ``semantic`` and ``fuzzy`` are mutually exclusive, and the resolved
    task name is returned as ``resolved_area`` with the ranked candidates in
    ``semantic_matches`` so you can audit and retry with a different one, and
    ``min_score`` -- a cosine threshold in ``[0, 1]`` -- drops weak aliases, so
    a description that matches nothing confidently returns an empty result
    rather than an arbitrary top pick); ``start``/``end`` as acquisition-date
    bounds -- an ISO
    ``YYYY-MM-DD`` date, a bare year/month (``2024``, ``2024-03``), or a
    relative expression (``today``, ``yesterday``, ``3 months ago``,
    ``last month``), resolved deterministically with no model call;
    ``products`` to restrict to product types
    (any o…

Input parameters:

- `area`
- `bbox`
- `canonical`
- `end`
- `fuzzy` (boolean)
- `intersects`
- `limit` (integer)
- `local`
- `max_incidence`
- `max_per_task`
- `max_resolution`
- `min_incidence`
- `min_score` (number)
- `place`
- `polarizations`
- `products`
- `semantic` (boolean)
- `start`

### `find_repeat_sites` (~2964 tokens)

Rank the archive's most repeat-imaged sites — where change detection has
    something to measure.

    The discovery step *before* every analysis verb. ``change`` / ``timescan`` /
    ``stack`` / ``pick_change_interval`` / ``narrate_change`` all answer *what*
    changed at a site, but each assumes the caller already knows *which* site to
    point them at. Umbra files every pass of an area under one task (site), so a
    site's coverage is just how many dated passes share its task; the sites with
    the most are exactly the ones where a time series exists to analyse. This
    tool ranks them, so ``find_repeat_sites → pick_change_interval →
    narrate_change`` is a complete chain a model can drive with no site known in
    advance — the deterministic answer to "where is there something to look at?"
    (the discovery moat; no model is called). Reach for this
    (or ``search_catalog(area=..., fuzzy=True)``) before ``semantic=True`` when
    the site name is roughly known.

    The filters scope the *pool* of acquisitions the ranking is computed over,
    and are the same ones ``search_catalog`` takes: ``bbox``
    (``[min_lon, min_lat, max_lon, max_lat]`` WGS84), ``intersects`` (a GeoJSON
    polygon, mutually exclusive with ``bbox`` / ``place``), ``place`` (free-text,
    geocoded to a bbox), ``area`` (a task-name substring, loosened by ``fuzzy``),
    ``start`` / ``end`` date bounds, ``products`` (GEC / SICD / SIDD / CPHD), and
    the SAR property filters ``polarizations`` / ``min_incidence`` /
    ``max_incidence`` / ``max_resolution``. ``top`` caps how many sites are
    returned, and ``min_passes`` is how many passes a site needs to qualify (2 is
    the minimum a change composite can use; raise it to find only deeply-revisited
    series), counted on the depth ``rank_by`` measures -- raw dated passes by
    default, the usable (comparable) series' depth under ``rank_by="comparable"``.

    ``rank_by`` chooses the order: ``"passes"`` (the default) ranks by…

Input parameters:

- `active_before`
- `active_since`
- `area`
- `bbox`
- `end`
- `first_before`
- `first_since`
- `fuzzy` (boolean)
- `intersects`
- `limit` (integer)
- `local`
- `max_incidence`
- `max_resolution`
- `max_revisit_days`
- `max_span_days`
- `median_revisit_days`
- `min_incidence`
- `min_passes` (integer)
- `min_span_days`
- `place`
- `polarizations`
- `products`
- `rank_by` (string)
- `start`
- `top` (integer)

### `get_item` (~513 tokens)

Return the full context card for one item.

    ``url`` is the JSON URL of an open-data STAC sidecar, a GEC/SICD (or other
    product) filename such as ``2025-05-17-17-43-46_UMBRA-08_GEC.tif``, or the
    acquisition stem ``2025-05-17-17-43-46_UMBRA-08``. A filename or stem is
    resolved through the local catalog index: the stem is matched against
    asset hrefs, which is what distinguishes ``sar-data/tasks/``,
    ``sar-data/task-data/``, and ``open-data/`` — the name itself does not.
    Zero matches is an error. More than one match lists the candidate STAC
    URLs; pass one of those. The hosted server resolves a filename or stem
    with the catalog index it already loaded. A local server does the same
    after ``umbra index fetch``.

    When the index contains a STAC URL, the indexed snapshot is returned —
    the same document ``search_catalog`` already answered from — rather than
    a live re-fetch that can disagree on asset filenames or product types.
    When the server is configured with a token (``$UMBRA_CANOPY_TOKEN``) and
    ``url`` is a bare acquisition id (no ``://``, and not a filename or stem),
    it is instead looked up in Umbra's authenticated commercial archive by a
    keyed STAC search — the retrieval complement to ``search_catalog`` over
    the paid catalog, since archive cards carry an ``id`` (not a fetchable
    sidecar URL) as their hand-off pointer. A filename or stem still resolves
    from the local open-data index when a token is set.

    On the public host a URL is fetched only when it is https on Umbra's
    public open-data bucket. Any other URL is refused before a request.
    A bare id that is not in the local index is refused the same way.

    The card (:meth:`UmbraItem.to_llm_context`) carries the id, ISO datetime,
    place, bbox, resolution, polarization *with the change-detection caveat*,
    the per-product-type explanations and asset URLs, and the mandatory
    attribution line — everything a model needs to reas…

Input parameters:

- `url` (string, required)

### `geocode_place` (~86 tokens)

Resolve a free-text place name to a bounding box via Nominatim.

    Returns ``{"bbox": [min_lon, min_lat, max_lon, max_lat], "display_name":
    ...}`` so the agent can inspect the box before searching, or pass it
    straight to ``search_catalog``'s ``bbox``.

Input parameters:

- `query` (string, required)

### `index_stats` (~162 tokens)

Report on the local catalog index, if one has been built or fetched.

    Lets a long-running agent decide whether searches will be instant (index
    present) or pay a live S3 walk, and how stale the snapshot is. ``end`` is
    the newest acquisition that is not ``datetime_suspect``.
    ``datetime_suspect_count`` is how many kept rows carry that flag.
    ``quarantined_future_count`` is how many source rows the last build
    dropped for a datetime more than a day ahead (they are not in the index).
    ``unique_captures`` is how many rows are the canonical copy of their
    collect; it equals ``items`` until republished copies have been linked.

### `quicklook` (~276 tokens)

Return a scene's quicklook PNG as an image block.

    Prefers a baked catalog preview (``preview="auto"``, the default) so a
    public host can show the radar scene without proxying Umbra COGs.
    **A baked preview is typically 512 px** (the published weekly sidecar).
    ``max_size`` applies only to a fresh ``preview="render"`` stream; when a
    cached thumbnail is smaller than requested, the caption says
    ``max_size`` was ignored *and* includes a JSON
    ``{"image": {source, width, height, requested_max_size, substituted}}``
    sidecar. For a higher-resolution picture (typically 1024 px), run a
    local ``uvx --from 'umbra-py[mcp]' umbra-mcp`` server, or download the
    GEC href from ``get_item``. ``preview="baked"`` refuses rather than
    stream; ``preview="render"`` always streams (needs ``[viz]``, refused
    on ``umbra serve --public``).

Input parameters:

- `asset` (string)
- `db` (boolean)
- `max_size` (integer)
- `preview` (string)
- `url` (string, required)

### `change_composite` (~167 tokens)

Composite 2-3 passes of one site into a change image.

    Pass the STAC URLs of two or three acquisitions of the *same* site in time
    order. Colors encode change: bright green = signal appeared after the first
    date, magenta = signal vanished, grey = unchanged. Refuses to mix
    polarizations (HH vs VV are not comparable). Returns the image block plus a
    caption naming the color semantics and attribution -- and, when a pass carries
    no polarization metadata so same-polarization could not be *verified*, a
    structured caution text block naming that gap.

Input parameters:

- `asset` (string)
- `db` (boolean)
- `max_size` (integer)
- `urls` (array, required)

### `timescan` (~96 tokens)

Summarize a whole time series into one activity image.

    Pass the STAC URLs of a site's passes; the timescan encodes per-pixel
    temporal statistics so bright/colored areas are *where activity happened*
    over the series. Returns the image block plus attribution.

Input parameters:

- `asset` (string)
- `db` (boolean)
- `max_size` (integer)
- `urls` (array, required)

### `stack_stats` (~1051 tokens)

Measure how much a site changed across its passes, as numbers.

    The quantitative counterpart to ``change_composite`` / ``timescan``: those
    return a picture of *where* change is, this returns the *how much*. Pass the
    STAC URLs of a site's passes (2 or more, any order); they are co-registered
    onto one shared grid and reduced to a per-pass statistics series plus a net
    baseline-to-latest record — mean/median/spread of each pass, the signed
    decibel change against the pass before it, the fraction of ground that moved
    past ``change_threshold_db``, and that fraction as an **area in km²**.

    Change is always reported in decibels (a ratio of backscatter is a difference
    on the log scale). The default ``crs="utm"`` puts the grid in the site's UTM
    zone so every cell covers the same ground and the area figures mean
    something; pass ``crs="EPSG:4326"`` for a lon/lat grid, and the areas come
    back ``None`` rather than wrong. ``extent="intersection"`` (the default)
    compares only ground every pass covers; ``"union"`` keeps all of it and
    compares per cell where two passes overlap. ``bbox`` (lon/lat
    ``[min_lon, min_lat, max_lon, max_lat]``) narrows the measurement to a
    sub-area, e.g. one facility inside the scene.

    ``blocks=N`` adds the *where* to the *how much*: the scene is cut into an
    N x N grid (6 is a good default; 0, the default, skips it) and the extra
    ``spatial`` key reports each block's own net change, a compass label and
    lon/lat centre to locate it by, and the consecutive pair of passes that
    block moved most between — plus ``peak_block`` and an ASCII ``grid_text``
    heat-map of the net change. Ask for it whenever the question is *where on
    this site* something happened, or when a scene-wide mean looks small but the
    picture from ``change_composite`` shows an obvious hot spot: a change
    confined to one corner is averaged away scene-wide and stands out per block.

    ``block_series=Tru…

Input parameters:

- `asset` (string)
- `bbox`
- `block_series` (boolean)
- `blocks` (integer)
- `change_threshold_db` (number)
- `crs` (string)
- `extent` (string)
- `max_size` (integer)
- `speckle_filter`
- `speckle_window` (integer)
- `urls` (array, required)

### `stack_provenance` (~467 tokens)

Check whether a site's passes are one measurement, before measuring them.

    ``stack_stats`` refuses a selection whose rasters were made by *different*
    ``umbra convert`` settings — a calibrated pass differenced against an
    uncalibrated one puts the difference between two conversions on the time
    axis and reports it as change on the ground. This is the question that
    refusal answers, asked ahead of it: it reads each acquisition's ``UMBRA_*``
    conversion record straight from its raster header (kilobytes per pass, no
    pixels, no co-registration) and groups the selection by what its pixel
    values *are*.

    Returns ``agrees`` (whether ``stack_stats`` would accept the selection),
    ``groups`` largest-first — each with the conversion ``record`` its members
    share, their ``item_ids`` and the ``hrefs`` to re-run on — plus ``shared``
    (the record they all agree on) when they agree, ``refusal`` (verbatim the
    error ``stack_stats`` would raise) when they do not, and ``unreadable`` for
    any source that could not be opened at all, which is an incomplete answer
    rather than a mixed one.

    Reach for it in two situations. **After** a ``stack_stats`` call fails with
    a provenance refusal: ``groups[0]["hrefs"]`` is the largest set of passes
    that *do* agree, so re-running ``stack_stats`` on those is a measurement
    rather than a guess — the refusal itself cannot name that subset. And
    **before** measuring a long series you did not assemble yourself, since the
    check costs a header read per pass and saves the whole cube when the answer
    is no.

    A series of Umbra's published products as they ship (the common case) agrees
    trivially: every pass reads as ``"(unrecorded)"``, which is one value, so
    ``agrees`` is true and ``shared`` is empty. **No model is called.**

Input parameters:

- `asset` (string)
- `urls` (array, required)

### `pick_change_interval` (~630 tokens)

Scan a site's whole series and name the two passes worth narrating.

    The deterministic first half of the "watch a site over time" story, and the
    step that turns a wall of passes into an answer. Given the STAC URLs of a
    site's passes (2 or more, any order), it co-registers them into a
    ``to_stack`` cube, reduces it with ``stack_stats``, and returns the *one*
    consecutive pass-pair whose measured change stands **furthest clear of the
    speckle detection floor** — the pair a reader should look at first. No model
    is called: a number picks the frames (the determinism boundary applied to
    frame selection), so the choice is reproducible and safe
    to quote.

    Why this exists as its own tool: ``narrate_change`` reads a *pair* of passes,
    but a site has many, and "which two?" is a measurement question, not a model
    one — a picture past three dates encodes nothing a model can separate, so the
    pair has to be chosen before the model is called. This answers it. The
    returned ``urls`` are the two chosen passes in time order, ready to hand
    straight to ``narrate_change`` (or ``change_composite`` to see them): the
    two tools chain into scan → narrate with no server and no model in the
    selection.

    Returns ``selected_interval`` (the interval's ``earlier_id`` / ``later_id``,
    their datetimes, the ``changed_fraction`` and signed ``mean_delta_db``, the
    cube's ``false_alarm_fraction`` speckle floor, the ``excess`` of the change
    over that floor, and ``stands_clear`` — whether the change cleared the floor
    by a usable margin), ``urls`` (the earlier then the later pass's STAC URL),
    and the license/attribution. When ``stands_clear`` is false the series' own
    largest change is still inside the speckle, so the pair is offered but the
    reader is warned the difference may be interference rather than change.

    ``selected_interval`` is ``None`` (and ``urls`` empty) when the series has
    fewer than two comparab…

Input parameters:

- `asset` (string)
- `change_threshold_db` (number)
- `crs` (string)
- `extent` (string)
- `max_size` (integer)
- `urls` (array, required)

### `download_asset` (~918 tokens)

Download one asset of an item to local disk, gated by a size check.

    SAR products can be multiple GB, so this is a two-step handshake: call it
    first with ``confirm=False`` (the default) to get the byte size without
    downloading, then again with ``confirm=True`` to fetch it. On a
    local or stdio server, ``confirm=True`` returns ``{asset, path, bytes}``.
    ``confirm=False`` returns a size-and-hint object and does not write a file.

    On a public host (``umbra serve --public``, COG streaming off),
    ``confirm=True`` does not transfer the file. It returns a link plan:
    ``mode`` ``"link"``, ``downloaded`` false, ``asset``, ``filename`` (a
    basename), the direct public ``href``, ``bytes``, and ``how_to_fetch``.
    When the href is https on the public open-data bucket, ``how_to_fetch``
    is ``curl -L -C - -o <filename> <href>`` and
    ``umbra download ITEM --asset ASSET --dest DIR``. ``bytes`` is the STAC
    ``file:size`` or ``size`` when that is a non-negative integer; otherwise
    the host HEADs that href for ``Content-Length``, with no redirects and
    no retries. A href that is not on that bucket is not requested:
    ``how_to_fetch.curl`` and ``how_to_fetch.umbra`` are null, ``bytes`` is
    null, and ``note`` says the commands were omitted. A 404 or 410 from
    an allowlisted HEAD raises. Any other HEAD failure, including a full
    quick-request slot, leaves ``bytes`` null and still returns the plan.
    The hosted server never transfers the file. A local
    ``uvx --from 'umbra-py[mcp]' umbra-mcp`` server downloads to your own
    disk. ``confirm=False`` on this host returns the same size-and-hint
    object and does not write a file. It HEADs for ``Content-Length`` only
    when the href is https on the public open-data bucket, with no retries,
    and it does not follow redirects. A 404 or 410 raises, and so does any
    other non-redirect HEAD error. A redirect leaves ``bytes`` null. A href
    outside the bucket is not request…

Input parameters:

- `asset` (string)
- `confirm` (boolean)
- `dest_dir` (string)
- `url` (string, required)

### `watch_site` (~461 tokens)

Report only the acquisitions **new** since the last check of this site.

    SAR's value for monitoring is its cadence, so the natural workflow is
    *standing*: run the same search each time and act only on what changed. This
    tool packages that idempotent delta — call it in one turn, come back a day
    (or a session) later and call it again, and it returns just the passes
    published in between, not the whole list again. The scheduler is you: ask the
    agent to check the site, and it reports the delta.

    Define the site with the same filters as ``search_catalog`` — ``place``
    (geocoded to a bbox), ``area`` (task/site-name substring, loosened by
    ``fuzzy``), ``bbox``, ``products``, and ``start``/``end`` date bounds. The
    watch is identified by a stable ``name`` derived from those filters (pass an
    explicit ``name`` to run several independent watches over the same site);
    ``reset=True`` re-establishes the baseline, reporting everything as new.

    State persists in the local catalog index's ``meta`` table (created on first
    use), so a watch survives across sessions with no extra setup. ``local``
    selects the search backend exactly as in ``search_catalog`` — leave it unset
    to use the on-disk index when present and a live S3 walk otherwise; for true
    monitoring a live walk (``local=false``) catches freshly published passes.
    **No model is called** — this is pure set arithmetic over the deterministic
    search — and the returned ``new_items`` are context cards ready to hand
    straight to ``change_composite`` / ``timescan``, closing the standing-analyst
    loop (new pass → composite → describe) without leaving the conversation.

Input parameters:

- `area`
- `bbox`
- `end`
- `fuzzy` (boolean)
- `local`
- `name`
- `place`
- `products`
- `reset` (boolean)
- `start`

### `find_similar` (~331 tokens)

Find archived scenes that **look like** the acquisition at ``url``.

    This is the one search that lives in the pixels, not the metadata: where
    ``search_catalog`` filters by date/bbox/task-name, this renders the query
    item's quicklook, embeds it, and ranks the pre-embedded scene index by visual
    (cosine) similarity — "find scenes that look like this flooded field / crowded
    berth / runway". The query item is excluded from its own results.

    Requires a scene-embedding index built ahead of time with ``umbra embed
    build`` (a sidecar ``catalog.embed.db`` beside the catalog index) and a
    user-supplied multimodal embedding key (``OPENAI_API_KEY``, optionally
    ``OPENAI_BASE_URL`` / ``UMBRA_SCENE_EMBED_MODEL``) — the only model call is
    turning the query image into a vector; ranking is deterministic. ``asset``
    picks which product's quicklook to embed (default ``GEC``; match how the index
    was built); ``model`` must match the index's embedding model. Returns the
    ranked matches as compact records (each with the acquisition's ``href``, so
    hand it to ``get_item`` / ``quicklook`` / ``change_composite`` next) plus the
    attribution line.

Input parameters:

- `asset` (string)
- `min_score` (number)
- `model`
- `top_k` (integer)
- `url` (string, required)

### `find_similar_text` (~221 tokens)

Find archived scenes matching a plain-language ``query`` over their imagery.

    Text-to-scene search: embeds ``query`` ("ships at a berth", "a flooded field")
    and ranks the stored *image* vectors by cosine similarity. It only works when
    the index was built and this query is embedded with the **same** joint
    CLIP-family model whose text and image encoders share a vector space (a
    dimension mismatch is reported as an error; ``model`` selects it).

    Requires the same prebuilt ``catalog.embed.db`` (``umbra embed build``) and
    embedding key as ``find_similar``; the only model call is turning the text
    query into a vector. Returns the ranked matches as compact records (each with
    the acquisition's ``href`` for ``get_item`` / ``quicklook``) plus attribution.

Input parameters:

- `min_score` (number)
- `model`
- `query` (string, required)
- `top_k` (integer)

### `describe_scene` (~361 tokens)

Return a SAR-literate reading of the scene at ``url``.

    The picture and the metadata card are produced deterministically; a model
    only interprets them. How that model is reached depends on whether this
    process holds a vision key:

    - **No key** (the public community host): this tool does **not** call a
      vision model. It returns the PNG plus a reading kit (SAR rules, the
      metadata card, the JSON schema). Produce the JSON, then call
      :func:`stamp_description` — that is the validation boundary
      (provenance-stamped ``{summary, observed_features, confidence,
      caveats}``). Until you stamp it, your prose is not pipeline output.
      A baked preview is typically 512 px; the kit names the size and
      that a local server can stream a higher-resolution GeoTIFF.
    - **Key configured** (local stdio): sends the picture to that vision
      model, validates through ``parse_description``, and returns the
      stamped object directly.

    The packaged SAR rules are the value over just looking at ``quicklook``:
    brightness is backscatter not sunlight, speckle is not structure, a dark
    patch may be radar shadow not water, one frame is not change.

    ``preview`` defaults to ``"auto"``: a baked catalog preview if this server
    has one, else a fresh render. ``"render"`` is refused on the public host.

Input parameters:

- `asset` (string)
- `db` (boolean)
- `max_size` (integer)
- `model`
- `preview` (string)
- `url` (string, required)

### `narrate_change` (~290 tokens)

Return a grounded reading of *what changed* between passes.

    Sibling of :func:`describe_scene`. The composite and the per-block dB grid
    are produced deterministically; a model only narrates change those numbers
    support. Pass the STAC URLs in time order; mixed polarizations are refused.

    This tool **streams Umbra COGs** to build the composite, so a public
    community host refuses it (use a local ``uvx --from 'umbra-py[mcp]'
    umbra-mcp`` server, or describe each pass with :func:`describe_scene` /
    :func:`quicklook` on baked previews). On a local server:

    - **No vision key:** returns the composite as an MCP image block plus a
      reading kit (SAR change primer, the dB grid, the JSON schema). **You**
      (the client's model) narrate, grounded in the numbers.
    - **Key configured:** sends picture + grid to that vision model, validates
      through ``parse_narration``, and returns a provenance-stamped
      ``{summary, changes[], confidence, caveats[], change_stats}`` object.

Input parameters:

- `asset` (string)
- `db` (boolean)
- `max_size` (integer)
- `model`
- `urls` (array, required)

### `stamp_description` (~171 tokens)

Validate a client-produced scene reading and stamp provenance.

    This is the interpretation boundary for the no-key kit path: you read the
    picture ``describe_scene`` returned, produce
    ``{summary, observed_features, confidence, caveats}``, and pass it here.
    The library checks the shape, stamps CC-BY and the AI-interpretation
    note (the model never sets those), and — when ``image`` is the record
    from the kit — appends a deterministic caveat if the picture was a
    smaller baked preview. Until this returns, the reading is unvalidated
    prose, not pipeline output.

Input parameters:

- `asset` (string)
- `image`
- `item_id`
- `model`
- `reading` (object, required)

### `stamp_narration` (~106 tokens)

Validate a client-produced change narration and stamp provenance.

    Sibling of :func:`stamp_description` for the no-key ``narrate_change``
    kit. Pass the JSON you produced plus the ``change_stats`` grid from the
    kit so the stamped object carries the numbers the prose was grounded in.

Input parameters:

- `asset` (string)
- `change_stats`
- `item_ids`
- `model`
- `reading` (object, required)

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/reesehammer-umbra-mcp/api#diagnostics

## Score history

- 2026-11-05: 64
- 2026-11-04: 64
- 2026-11-03: 64
- 2026-11-02: 63
- 2026-11-01: 63
- 2026-10-31: 63
- 2026-10-30: 62
- 2026-10-29: 62
- 2026-10-28: 61
- 2026-10-27: 61
- 2026-10-26: 60

## Common questions

### What is the Umbra open SAR archive MCP server?

Umbra open SAR archive is an MCP server listed in the public MCP registry as io.github.reesehammer/umbra-mcp. Search, preview, and measure Umbra open SAR from any MCP client. Umbra ships no search API. This page covers its hosted endpoint (https://api.umbra-py.space/mcp).

### Is the Umbra open SAR archive MCP server safe to use?

Umbra open SAR archive scores 64 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the Umbra open SAR archive MCP server expose?

Umbra open SAR archive exposes 19 tools: search_catalog, find_repeat_sites, get_item, geocode_place, index_stats, and 14 more. Their descriptions and schemas cost roughly 10,365 tokens of context every time the server is loaded.

### Does the Umbra open SAR archive MCP server require authentication?

Its publisher declares no required credentials for Umbra open SAR archive. We have not been able to confirm that against the live endpoint, and a server can require authorisation without declaring it here.

### Is the Umbra open SAR archive MCP server still maintained?

Umbra open SAR archive is still listed in the MCP registry, though our most recent checks did not reach this channel. We last reached this channel on 3 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

## Links

- Remote endpoint: https://api.umbra-py.space/mcp
- Repository: https://github.com/reesehammer/umbra-py
- Changelog RSS feed: https://verifymcp.io/servers/reesehammer-umbra-mcp/api.xml
- Changelog JSON feed: https://verifymcp.io/servers/reesehammer-umbra-mcp/api.json
- HTML version of this page: https://verifymcp.io/servers/reesehammer-umbra-mcp/api
