Name: Sellat
Author: skanthemore

Sellat MCP

Proof of existence for files from any MCP client: hashed locally, anchored on Polygon and Bitcoin.

Grade A Local · stdio API key 9 tools v0.3.3 MIT

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96/100

trust score

downloads a day

local

runs on your machine

536

downloads in 30d

What it does

Proof of existence for files from any MCP client: hashed locally, anchored on Polygon and Bitcoin.

Quickstart

# 1 — add it to Claude Code
claude mcp add --scope user --env 'SELLAT_API_TOKEN=${SELLAT_API_TOKEN}' --transport stdio sellat-mcp '--' npx -y sellat-mcp

# 2 — ask your agent for something these tools do
#   sellat_hash, sellat_find, sellat_stamp and 6 more

It needs SELLAT_API_TOKEN: this reads it from your environment, so export it first.

Sellat costs nothing on mcprush: there is no plan to choose here, no cap to set and nothing mcprush can bill you for.

Publisher

skanthemore1 server

1 category

All 1 server

Installation

Where are you running it?

Every route below installs the same thing and ends at the same approval screen. This one runs on your machine: your client starts Sellat as a process under your own user, with your files and your network, so the tool surface below is what it can do to your computer rather than to a server somewhere else. Its scan result is on the Security tab — read the surface before you approve it.

Claude Codedeclared by this listing

This is a public server: you run it yourself and this marketplace is not in the path. You need Node.js — the current LTS (24) is the safe choice; npx comes with it. Claude Code registers it in one command; --scope user makes it available in every project. Claude Code reads SELLAT_API_TOKEN (Your Sellat API key (sellat_…), from sellat.app → Dashboard → API) from your environment each time it starts the server, so the value stays out of its config: export it in your shell profile (macOS, Linux), or run setx SELLAT_API_TOKEN … and open a new terminal (Windows). The '--' is in quotes so that PowerShell passes it on.

claude mcp add --scope user --env 'SELLAT_API_TOKEN=${SELLAT_API_TOKEN}' --transport stdio sellat-mcp '--' npx -y sellat-mcp

Reconnect, or start a new session, and the tools appear in the model’s tool list.

Free on mcprush, and it runs from its publisher’s own package: this marketplace is not in the path, so there is no key of ours to hold and no card to add.

What it asks of you

It reaches a system of yours, so it needs your own credential rather than the publisher’s: SELLAT_API_TOKEN — Your Sellat API key (sellat_…), from sellat.app → Dashboard → API. You set it in your own client’s config, on your machine — this marketplace never holds it.

What it writes

One config entry your client uses to start the process locally. A local server runs with your file system and your network, which is why it is priced without metering.

What you approve

9 tools, with what each one reads, writes and reaches shown before you agree — the same list on every route above. Read the tool surface.

Tool surface

What the model actually sees. Descriptions are diffed on every release — see version history.

Only tools that write or reach the network

Read from its source code. A server that builds its tool list when it starts can list more tools than this.

Compute the SHA-256 fingerprint of a local file. Runs entirely on this machine: nothing is sent anywhere. Useful to compare two files or to check a fingerprint someone gave you.

Parameter	Type	Required	Notes
path	string	yes	Absolute path of the file (~ is expanded).

Find files on this computer by name, in the user's Downloads, Desktop, Documents and Pictures folders (their real names on this system), newest first. Reads names only, never contents. Use it whenever the user refers to a file without giving its path. With no query it lists the most recent files.

Parameter	Type	Required	Notes
query	string	no	Words from the file name, any order, case and accents ignored ("contrato alquiler", "pdf").
where	string	no	Which folder to search. Default all four.
folder	string	no	Search this folder instead (absolute path, ~ expanded).
modified_within_days	number	no	Only files changed in the last N days ("yesterday" = 2).

Create a SELLAT proof of existence for a local file. The file is hashed on this machine and only its SHA-256 (plus the name and size) is sent; the file itself never leaves the computer. Stamping the same file again returns the existing proof (the earlier date is the stronger one). Set…

Parameter	Type	Required	Notes
path	string	yes	Absolute path of the file to protect (~ is expanded).
name	string	no	Name shown on the certificate. Defaults to the file name.
qualified	boolean	no	Also issue the qualified timestamp (eIDAS). Spends one seal. Only if the user asked for it.

The current state of a proof: whether its batch is anchored on Polygon, the Bitcoin confirmation, the qualified seal and its URLs.

Parameter	Type	Required	Notes
proof_id	string	yes	The SELLAT proof id (returned by sellat_stamp or sellat_list).

The account's proofs, newest first, one page at a time.

Parameter	Type	Required	Notes
limit	integer	no	Page size, 1–100 (default 25).
cursor	string	no	next_cursor from the previous page.

Issue the qualified electronic timestamp (eIDAS, RFC 3161) for an existing proof. Spends one seal from the account: call it only when the user explicitly asked for it. With no seals left it returns the link to buy them on the web. Calling it again on a sealed proof returns the existing seal…

Parameter	Type	Required	Notes
proof_id	string	yes	The SELLAT proof id (returned by sellat_stamp or sellat_list).

The account's plan, qualified seals remaining, custody usage and today's proof budget, with the link to buy seals.

No parameter schema on file.

Save a proof document to this computer: the PDF certificate, the evidence package (ZIP with proof.json, the OpenTimestamps file and instructions to verify without SELLAT) or the RFC 3161 token of the qualified seal (.tsr). Never overwrites an existing file.

Parameter	Type	Required	Notes
proof_id	string	yes	The SELLAT proof id (returned by sellat_stamp or sellat_list).
kind	string	yes	certificate = PDF, evidence = ZIP package, tsr = qualified seal token.
lang	string	no	Language of the certificate or package; use the user's language. Default en.
directory	string	no	Folder to save into. Default: SELLAT_DOWNLOAD_DIR, else ~/Downloads.

Check that a file matches a SELLAT proof and that the proof is really anchored on the blockchain, without trusting SELLAT: the file is hashed locally, the Merkle path is recomputed, and a public blockchain node is asked whether the anchoring transaction carries the root. Give the proof as a…

Parameter	Type	Required	Notes
file_path	string	yes	Absolute path of the file to check.
proof_path	string	no	Path to proof.json or to an evidence package (.zip).
proof_id	string	no	A proof id, when there is no proof file at hand.
offline	boolean	no	Skip the blockchain check (math only): proves no date. Default false.

Free

$0 forever

Every tool, no call limit
No card, and mcprush charges nothing for it
Source published under MIT
Runs on your machine — nothing of it reaches our gateway
Nothing to cap, because mcprush bills nothing

Nothing here is billable: mcprush charges nothing to install Sellat or to call it, at any volume.

ATrust score 96 / 100

Release 0.3.3 · scanned 3 Nov 2026

Two independent axes, because powerful and malicious are different questions. The grade is threat only. The capability level is blast radius, and it is never a penalty on the grade — it is priced as one subtract-only term in the score, where you can see it.

Threat score100

Client score96

Findings0 threat · 1 capability

Capabilitymoderate

Coveragesource

Verificationrepo

Surface digestcff94950f1faf2791caf1bcc3f40f835fc04e034b6733484e735a13c67e5b54e

Score vectorthreat 100 → client 96

Term	Level	What it prices	Points
capability-exposure	moderate	capability blast radius (moderate) — client exposure if the model is manipulated	−3
verification-discount	repo	publisher verification (public source) — no provenance, but the source is public and inspectable	−1
coverage-honesty	source	inspection depth (source) — how much of the target the scan could see	−0

score = clamp(round(threatScore − E_cap − E_ver − E_cov), 0, 100). No model, no opinion, no network call at scoring time: the same methodology version against the same bytes always produces this number, and every line above is a field of the report rather than a summary of it.

What the scan could actually read

A grade is only as meaningful as its coverage, so the scanner publishes its own depth before it publishes its result.

Tool surfaceread

Implementation sourceread

Package metadataread

Live transportnot available

Tools were statically extracted from the published source (9 recovered), not enumerated from a running server. Tool-poisoning, Unicode-smuggling, capability and toxic-flow analysis ran on this inferred surface, but a mis-parsed registration could be missed or mis-attributed, so tool-derived findings are capped below “confirmed”. To grade the real runtime surface, scan the running server: --command "npx -y <package>".

Capability — what it could do if the model were manipulated

Tags derived from each tool’s schema and the implementation, not from what the tool calls itself. moderate is the level these add up to.

Tool	Capability tags	Why the tag was assigned
sellat_hash	no tags
sellat_find	no tags
sellat_stamp	external-sink	external-sink: declares readOnlyHint: false, openWorldHint: true
sellat_status	untrusted-input	untrusted-input: declares openWorldHint: true (interacts with entities outside the server)
sellat_list	untrusted-input	untrusted-input: declares openWorldHint: true (interacts with entities outside the server)
sellat_seal	external-sink	external-sink: declares readOnlyHint: false, openWorldHint: true
sellat_account	untrusted-input	untrusted-input: declares openWorldHint: true (interacts with entities outside the server)
sellat_download	untrusted-inputexternal-sink	untrusted-input: keyword "download"; external-sink: declares readOnlyHint: false, openWorldHint: true
sellat_verify	untrusted-input	untrusted-input: declares openWorldHint: true (interacts with entities outside the server)

Toxic-flow graph

The lethal trifecta, checked as a graph rather than as a checklist: untrusted input, a sensitive source and an external sink have to meet before there is a path worth worrying about.

flow-1

Untrusted input can drive an external action even though no sensitive source is exposed.

Supply chain and provenance

Integrityfirst-seen

Surface digestcff94950f1faf279

Scanned2026-11-03

This is the first scan of this surface here, so there is nothing yet to compare it against.

Every result on this tab comes from one deterministic pass over the published package — offline, rule by rule, and auditable line by line above. Same methodology version, same bytes, same score.