MCP HeartbeatTHE MCP OBSERVATORY
Public workspace

Explore

Evidence for your next connection.

Independent measurements of remote MCP servers. Every observation has a timestamp.

Read-only probes

MCP server · AI / LLM tooling

Card Mailer

Print and mail 5x7 holiday and thank-you photo cards to a US address list. $2.49/card incl. postage.

Checks passed
11 / 22

3 failed · 8 not measured

Median response
107 ms

Median of successful probes over 7 days

30-day uptime
Not measured

Share of countable probes over 30 days, including daily rollups. Auth challenges are excluded.

Discovered tools
6

Tool definitions returned by this server

Independent monitoring

Health & checks

Status history

Outdated check

Last connection measurement is over 24 hours old. Current availability is unknown.

Last checked
Check summary by test group
Test areaPassedFailedUnmeasured
ConnectionCan a client connect and discover tools?
500
Reliability & speedDoes it respond consistently and quickly?
004
Access & authenticationWhat is required to use this server?
102
Tool qualityAre the tool definitions usable by an agent?
310
Publisher identityCan the publisher be traced to its source?
222

Unmeasured means there is not enough evidence to decide. How these checks work

Inspect individual checks 22 recorded

Core

  • Pass
    Reachable

    Latest probe returned HTTP 200 in 107 ms.

  • Pass
    Valid handshake

    protocolVersion 2025-11-25, serverInfo.name card-mailer.

  • Pass
    Lists tools

    tools/list returned 6 tools.

  • Pass
    Current protocol

    Negotiated 2025-11-25. The bar is 2025-06-18 or newer.

  • Pass
    HTTPS

    The endpoint URL is https.

Performance

  • Not measured
    Fast (p50)

    Median latency 107 ms over 1 samples in 7 days. The bar is 1000 ms. Need at least 5 samples.

  • Not measured
    Consistent (p95)

    95th percentile 107 ms over 1 samples in 7 days. The bar is 3000 ms. Need at least 20 samples.

  • Not measured
    Reliable (uptime)

    1 of 1 attempts returned a tool list in 30 days (100%). The bar is 99%. Need at least 30 samples.

  • Not measured
    Stable tool list

    Fewer than two successful probes in 30 days, so tool-list stability is not measured.

Access

  • Pass
    Open access

    tools/list succeeded with no credential, and the record declares none.

  • Not measured
    Standard auth

    Auth is not required, so the OAuth metadata check does not apply.

  • Not measured
    Free tier cited

    No publisher quote has been checked.

Tools

  • Pass
    Tools described

    Every tool description is at least 20 characters.

  • Pass
    Valid input schemas

    Every inputSchema is a JSON Schema object.

  • Fail
    Parameters documented

    17 of 44 parameters have a description (39%). The bar is 80%.

  • Pass
    Safety hints

    Every tool sets readOnlyHint or destructiveHint.

Publisher

  • Pass
    Verified namespace

    Listed in the Official MCP Registry.

  • Fail
    Website matches publisher

    The website host does not match the reverse-domain namespace.

  • Fail
    Source repo linked

    No repository URL is on file.

  • Not measured
    Repo owner matches

    This namespace is not an io.github login, so the owner comparison does not apply.

  • Pass
    Recently updated

    Updated 2026-10-31T07:56:07.301004Z, within 180 days.

  • Not measured
    Open-source licence

    No GitHub repository to ask about a licence.

Start using Card Mailer

Connect to this server

Choose your client, copy the configuration, then enable the server in your client’s MCP settings.

Run this command in your terminal, then restart Claude Code.

Claude Code

claude mcp add --transport http card-mailer https://cards.onmax.me/mcp/claude

Capabilities

Tools 6

create_mailing

Creates an unpaid order for the ready recipients in a saved list and the selected saved card design. Returns a cards.onmax.me link for the user to review recipients and pay. Nothing is printed, mailed or charged until the user pays on that page. Rows needing fixes are excluded. Each call creates a separate order link. An optional US sender address is printed as the return address.

Discovered
design_card

Creates or edits a printed 5x7 postcard with a front greeting, optional photo, back message and sign-off. Downloads an attached photo or public HTTPS photo URL to cards.onmax.me. Without a photo, the greeting appears on a solid color. An existing design_id edits that design; omitted fields remain unchanged. The back message is user-written or user-approved text of up to 500 characters. Arranges supplied photos and text in a print template without generating images.

Discovered
fix_address

Corrects or removes a recipient in a saved list by row number. Supplied fields replace stored values; omitted fields remain unchanged. An unreadable row needs name, line1, city, state and zip. Rechecks required fields and US address format, plus USPS verification when configured. Format checks do not confirm deliverability. remove: true excludes the recipient. Lists belonging to paid orders cannot be changed.

Discovered
get_mailing_status

Returns a Card Mailer order's payment, printing, mailing or delivery status, send date, estimated arrival and per-recipient counts. The mailing_id is the last part of the order link. Does not change the order or track other USPS mail.

Discovered
import_address_list

Imports US postal recipients from pasted text, CSV or XLSX into a saved list. Checks required fields and US address format; USPS verification runs only when configured, and usps_checked reports whether it ran. Format checks do not confirm deliverability. Returns list_id, ready counts and row problems. An existing list_id appends recipients, up to 300. Not for email, non-US addresses or advertising to purchased or rented lists.

Discovered
quote_mailing

Calculates the unit price including First-Class postage, total for ready recipients, send date and estimated arrival window for a saved US recipient list. A saved design_id includes that design's current front and back preview. Null design_id produces a price-only quote with preview_included: false. arrive_by adds the latest safe send date and whether the requested date can be met. Does not create an order or charge money.

Discovered

Recent measurements

Probe history

View status
Latest stored probes. Raw probe rows are kept for 14 days.
CheckedResultResponseTools
Connected107 ms6