MCP servers › com.yetanotherbrowser › yab
MCP server · registry snapshot 2026-10-23 · last tested 2026-10-23
com.yetanotherbrowser/yab
Your own signed-in Mac browser for any agent: open, read and act in tabs. Local and free. — the publisher's description
Summary
com.yetanotherbrowser/yab is a local MCP server listed in the official MCP registry at version 0.2.1. On 2026-10-23 ProtocolProbe started its published package in an isolated sandbox in read-only mode and read its inventory: 69 tools, 0 resources and 0 prompts.
Record checks
- met: Registry entry is active and says how to run it
- met: Source repository link opens
- met: Repository is not archived
- met: Code pushed to the repository in the 90 days before our check
- not met: Repository publishes a security policy (SECURITY.md)
- met: Package names its licence with a standard (SPDX) identifier
- met: The version the registry lists can be installed and is not withdrawn
- not met: npm package carries build provenance (attestation)
- met: No known critical or high advisory in the package or its dependencies
- #3,341 of 15,112 packages by monthly downloads, tied with 8 others
- Not ranked by stars: 0 stars (ranked from 10)
From public records, not a safety rating. Each check with its reason · Is it safe to install?
Key facts
- Runs
- local package
- Transport
- standard input/output
- Package
- npm · listed version behind the latest release
- License
- MIT
- Dependencies
- no known high or critical advisories
- Repository
- public
- Tools
- 69
- Described as changing data
- 37 of 69 toolsAI-classified
- Mainly works on
- a web browser or desktop applicationsAI-classified
- Topic
- search-and-web-dataAI-classified
- Pricing
- freeAI-classified
- Last tested
- 2026-10-23
Worth knowing before you connect it
- 37 tools are described as changing something (native_apply, native_undo, open, …): our AI model's reading of the descriptions, not something we tested. We did not call them.
- The registry lists 0.2.1; 0.2.3 is newer (1 release).
Each line comes from a section below, with its source and date.
How fresh this is
- Live-tested
- yes, a real session (not a text-only review)
- Last tested
- 2026-10-23
- Mode
- read-only (no tool calls)
- Latest version
- 0.2.1, published 2026-10-12 (registry, as of the 2026-10-23 snapshot)
- First listed version
- 2026-10-09 (earliest version still in the registry; older removed versions would be earlier)
- Version history
- 4 versions listed, 2026-10-09 to 2026-10-12; 4 in the 90 days before the 2026-10-23 snapshot.(versions still listed in the registry only)
Most recent 4 versions
0.2.1· 2026-10-120.2.0· 2026-10-120.1.1· 2026-10-100.1.0· 2026-10-09
- Registry data
- snapshot 2026-10-23
- Package and repository
- checked 2026-10-22
- Engine
- mcp-runtime-engine@0.1.0 · sdk@1.32.0
Changes since the last refresh
New in the registry: not in the list of 2026-10-04, listed on 2026-10-23 with version 0.2.1 (published 2026-10-12).
Source: the official MCP Registry list on 2026-10-04 and on 2026-10-23.
What it is
What does this server offer?
Observed inventoryWhat it mainly works on, as our AI model read its tool descriptions: a web browser or desktop applications.
37 of 69 tools are described as changing something (creating, editing, deleting, sending or running). For 1 the reading was uncertain, so no mark is shown.
- devtools_commentsreads or searches
“Read user-authored comments on elements of an already inspected, non-private tab.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
1 input, 1 required
tabstringrequired“Tab id, as `open` or `tabs` gave it”
- devtools_consolereads or searches
“Read recorded Console messages from an already inspected, non-private tab.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
2 inputs, 1 required
limitintegertabstringrequired“Tab id, as `open` or `tabs` gave it”
- devtools_networkreads or searches
“Read sanitized request metadata recorded by the tab's Developer Tools.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
2 inputs, 1 required
limitintegertabstringrequired“Tab id, as `open` or `tabs` gave it”
- devtools_tracereads or searches
“Read the WebKit Performance recording's event names, durations and nesting.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
2 inputs, 1 required
limitintegertabstringrequired“Tab id, as `open` or `tabs` gave it”
- devtools_stylesreads or searches
“Read the currently selected element's matched and computed styles from Developer Tools.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
1 input, 1 required
tabstringrequired“Tab id, as `open` or `tabs` gave it”
- native_contextreads or searches
“Read Yab's own current settings, spaces, tabs, mail accounts, permissions and this task's native operations.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
8 inputs
sectionstringincludeCatalogbooleanactionstring“Read-only action preview; give its target and arguments to get the exact resourceVersion.”offsetintegertargetobjectlimitintegerargumentsobjectquerystring
- native_actionsreads or searches
“List native Yab actions with their strict argument schemas, targetKind, undo support and permission requirements.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
1 input
querystring
- native_applydoes something elsedescribed as changing data
“Perform a native Yab action explicitly requested by the user: settings, spaces, tabs, page fonts or connecting Gmail.”
Publisher declares: read-only no · destructive yes · idempotent no · open-world no
5 inputs, 4 required
requestIdstringrequiredexpectedVersionstringargumentsobjectrequiredtargetobjectrequiredactionstringrequired
- native_operationreads or searches
“Read this task's native operation by operationId, or wait for a change up to seconds (0 to 10).”
Publisher declares: read-only no · destructive no · idempotent no · open-world no
3 inputs, 1 required
operationIdstringrequiredcancelbooleansecondsnumber
- native_undodescribed as changing data
“Undo a native change of this task by its changeId (or the last undoable change).”
Publisher declares: read-only no · destructive no · idempotent no · open-world no
1 input
changeIdstring
“List the tabs open in Yab, the user's web browser: the user's and the agents'.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
Takes no inputs.
“Open a web page (URL) in a new agent tab in Yab, the user's browser, signed in to their sites, beside the user's tabs (never in front of them: `show` puts one there when the user asked to see it).”
Publisher declares: read-only no · destructive no · idempotent no · open-world yes
3 inputs
urlstringurlsarrayspacestring“A space's name, as `spaces` lists it”
Show 57 more tools
- spacesreads or searches
“List the user's spaces: sets of tabs, some signed in as someone else, with cookies of their own.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
1 input
sitestring“A site, as github.com or a URL”
“Send an agent tab to a URL, or back, forward or reload.”
Publisher declares: read-only no · destructive no · idempotent no · open-world yes
2 inputs, 2 required
urlstringrequired“A URL, or back, forward, reload”tabstringrequired“Tab id, as `open` or `tabs` gave it”
“Read a web page in a browser tab as an accessibility tree with ref ids.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
3 inputs, 1 required
refstring“Element ref from the latest snapshot, e.g.”tabstringrequired“Tab id, as `open` or `tabs` gave it”interactiveboolean
“Click an element by ref, as a real mouse click.”
Publisher declares: read-only no · destructive yes · idempotent no · open-world yes
4 inputs, 1 required
xnumberynumbertabstringrequired“Tab id, as `open` or `tabs` gave it”refstring“Element ref from the latest snapshot, e.g.”
“Replace the text in a field by ref (inputs, text areas, editors), or without ref, type into whatever has focus (after clicking into a field in a frame, say).”
Publisher declares: read-only no · destructive yes · idempotent no · open-world yes
4 inputs, 2 required
tabstringrequired“Tab id, as `open` or `tabs` gave it”submitbooleantextstringrequiredrefstring“Element ref from the latest snapshot, e.g.”
- choosecontrols a browser or desktopdescribed as changing data
“Pick an option in a <select> by its value or label.”
Publisher declares: read-only no · destructive no · idempotent no · open-world yes
3 inputs, 3 required
tabstringrequired“Tab id, as `open` or `tabs` gave it”valuestringrequiredrefstringrequired“Element ref from the latest snapshot, e.g.”
“Press keys on the focused element, as real key events: Enter, Tab, Escape, Backspace, ArrowDown, PageDown, Meta+a, or plain characters.”
Publisher declares: read-only no · destructive yes · idempotent no · open-world yes
2 inputs, 2 required
keysstringrequiredtabstringrequired“Tab id, as `open` or `tabs` gave it”
“Rest the pointer on an element, as a mouse would: menus that open on hover open.”
Publisher declares: read-only no · destructive no · idempotent no · open-world yes
2 inputs, 2 required
tabstringrequired“Tab id, as `open` or `tabs` gave it”refstringrequired“Element ref from the latest snapshot, e.g.”
“Drag an element with the mouse: onto another element (to, its ref; the dragged one lands before it) or by dx, dy pixels.”
Publisher declares: read-only no · destructive yes · idempotent no · open-world yes
5 inputs, 2 required
tabstringrequired“Tab id, as `open` or `tabs` gave it”dynumberdxnumberrefstringrequired“Element ref from the latest snapshot, e.g.”tostring“Element ref from the latest snapshot, e.g.”
- dialogcontrols a browser or desktopdescribed as changing data
“Answer what the page asked with alert, confirm or prompt: accept (OK) or not (Cancel), and text for a prompt.”
Publisher declares: read-only no · destructive yes · idempotent no · open-world yes
3 inputs, 2 required
tabstringrequired“Tab id, as `open` or `tabs` gave it”acceptbooleanrequiredtextstring
“Scroll the page, or the box around an element by ref (lists marked scrolls), by dy pixels (negative is up).”
Publisher declares: read-only no · destructive no · idempotent no · open-world yes
3 inputs, 1 required
refstring“Element ref from the latest snapshot, e.g.”tabstringrequired“Tab id, as `open` or `tabs` gave it”dynumber
“Run JavaScript that drives tabs with the same tools, several steps in one call: loops over pages, forms filled in a go, a list scrolled until a row shows.”
Publisher declares: read-only no · destructive yes · idempotent no · open-world yes
1 input, 1 required
codestringrequired“JavaScript; see the description for what it has”
“A tab's whole visible text, for reading articles and results.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
1 input, 1 required
tabstringrequired“Tab id, as `open` or `tabs` gave it”
“A picture of a tab as it is now, for when the snapshot is not enough.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
1 input, 1 required
tabstringrequired“Tab id, as `open` or `tabs` gave it”
“Wait for a tab to finish loading, or until its text contains `for`.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
3 inputs, 1 required
forstringsecondsnumbertabstringrequired“Tab id, as `open` or `tabs` gave it”
“Run JavaScript in an agent tab (isolated from the page's own scripts, same DOM) and return its value: a promise's, awaited up to 20 s, when the script is one expression (an async IIFE) or uses await …”
Publisher declares: read-only no · destructive yes · idempotent no · open-world yes
2 inputs, 2 required
tabstringrequired“Tab id, as `open` or `tabs` gave it”jsstringrequired
“Close an agent tab.”
Publisher declares: read-only no · destructive no · idempotent no · open-world no
1 input, 1 required
tabstringrequired“Tab id, as `open` or `tabs` gave it”
“Put a tab in front of the user as one of theirs: yours comes out of this task's folder, stays after the task, in the space it is signed in to.”
Publisher declares: read-only no · destructive no · idempotent no · open-world no
1 input, 1 required
tabstringrequired“Tab id, as `open` or `tabs` gave it”
“Search what you know about the user from earlier tasks, who they are, their accounts and sites, people, projects, preferences.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
2 inputs, 1 required
queriesarrayrequiredmax_resultsnumber
“Read one memory page whole: USER (who the user is), MEMORY (how to work for them), TAXONOMY (where things go), a subject page such as people/jane-doe, companies/acme, sites/github.com, projects/…, or…”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
1 input, 1 required
filestringrequired
“The user's profile for forms: name, headline, company, role, location, linkedin, x, github, website, telegram, instagram, bio (a sentence), about (a paragraph).”
Publisher declares: read-only no · destructive yes · idempotent yes · open-world no
2 inputs
setobjectsourcestring“Where the values came from: LinkedIn, their site, GitHub, X, memory”
- form_answerscreates or changes datadescribed as changing data
“Answers the user typed into web forms, kept with nothing asked once the form went through, so Yab fills the same question on the next form.”
Publisher declares: read-only no · destructive yes · idempotent yes · open-world no
2 inputs
keeparraydroparray
“Keep something for later tasks.”
Publisher declares: read-only no · destructive yes · idempotent yes · open-world no
3 inputs, 2 required
replacingstringfilestringrequiredtextstringrequired
“The user's browsing history.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
3 inputs
sitestring“A host, e.g.”daysnumberquerystring
“Watch a thread for someone's reply: every two hours for `days` (default 3), Yab quietly checks it and, when the reply comes, puts it on the user's new tab.”
Publisher declares: read-only no · destructive no · idempotent no · open-world yes
4 inputs
urlstring“The thread's own address”daysnumberstopstringwhostring“Whose reply, a name”
“Hand the user what needs them, as quiet rows under a new tab's field (most urgent first; four show), and say which rows already there are dealt with.”
Publisher declares: read-only no · destructive no · idempotent no · open-world no
2 inputs, 1 required
itemsarrayrequiredresolvedarray“Ids of rows already on the new tab that are dealt with now”
- boostsreads or searches
“List saved site boosts, their sites, permissions and state.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
Takes no inputs.
- boost_readreads or searches
“Read the files of a saved boost or this task's trial before changing it.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
1 input, 1 required
namestringrequired
“Yab's skills: how particular sites work for an agent (Gmail, GitHub, LinkedIn, Amazon, …), a line each.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
Takes no inputs.
“Read one skill whole, by name.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
1 input, 1 required
namestringrequired
“Ask the user to take over a tab, sign in, pass a captcha, enter a code, and wait until they say they are done (up to `seconds`, default 300; call again to keep waiting).”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
5 inputs, 2 required
reasonstringrequired“What the user should do, at most 60 characters, e.g.”optionalboolean“The task can go on without it: don't wait”detailstring“Anything more, shown only if they open it”tabstringrequired“Tab id, as `open` or `tabs` gave it”secondsnumber
“Ask the user to pick: a question with up to four options (they may also write their own), shown at the foot of a tab (yours, or the one named).”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
5 inputs, 2 required
detailstringquestionstringrequired“At most 60 characters”optionsarrayrequiredtabstring“Tab id, as `open` or `tabs` gave it”secondsnumber
“Sign in on this tab's page with a password Yab has saved for the site (the user may be asked first).”
Publisher declares: read-only no · destructive no · idempotent no · open-world yes
2 inputs, 1 required
tabstringrequired“Tab id, as `open` or `tabs` gave it”userstring“The account's name or email, when there are several”
- autofillcontrols a browser or desktopdescribed as changing data
“Fill a form on this tab with what Yab keeps for the user.”
Publisher declares: read-only no · destructive no · idempotent no · open-world yes
3 inputs, 2 required
tabstringrequired“Tab id, as `open` or `tabs` gave it”cardstring“The last four digits of the card to use”whatstringrequired
“Give the page files from this Mac (the user may be asked first): ref is what attaches a file (Attach, a paperclip, a file field).”
Publisher declares: read-only no · destructive yes · idempotent no · open-world yes
3 inputs, 2 required
refstring“Element ref from the latest snapshot, e.g.”filesarrayrequiredtabstringrequired“Tab id, as `open` or `tabs` gave it”
“Download a file: click ref (a download link or button), or fetch url with the tab's cookies.”
Publisher declares: read-only no · destructive no · idempotent no · open-world yes
3 inputs, 1 required
urlstringrefstring“Element ref from the latest snapshot, e.g.”tabstringrequired“Tab id, as `open` or `tabs` gave it”
“Save a tab's page as a PDF in the task's folder; returns the path.”
Publisher declares: read-only no · destructive no · idempotent no · open-world no
1 input, 1 required
tabstringrequired“Tab id, as `open` or `tabs` gave it”
“Read a URL with the user's cookies, no tab needed: a site's feed, export, print view or JSON API, as its own page would ask.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world yes
7 inputs, 1 required
spacestring“A space's name, for its sign-ins; without, where the site is signed in”methodstringtabstring“Tab id, as `open` or `tabs` gave it”bodystringtypestring“Content type of a POST body, application/json unless said”htmlboolean“Keep HTML as it is rather than its text”urlstringrequired
- mail_triagereads or searches
“The user's mail as yab already sorted it on this Mac: what needs them (with what each wants and any date it names), and what they are waiting on.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
Takes no inputs.
“Search all of the user's mail, of any age: plain words, a name, an address, or Gmail's operators (from:, to:, cc:, subject:, has:attachment, filename:, is:unread, is:starred, label:, in:, before:, af…”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world yes
2 inputs, 1 required
limitnumberquerystringrequired
“A thread of the user's mail as text, oldest message first, with its labels by name, the files each message carries (name, type, size; read one with mail_file), and, on the user's own mail sent with r…”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world yes
1 input, 1 required
threadstringrequired
- mail_filereads or searches
“The words of a file a thread of the user's mail carries: a PDF's text or a text file's, at most 20,000 characters, for answers that may be in an attachment (an invoice's total, a contract's dates).”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
3 inputs, 1 required
threadstringrequirednamestringindexnumber“The file's number in mail_read's Files line”
“Write a reply in a thread (thread), a forward of a thread's last mail (thread, forward: true, to), or a new mail (to, subject), as a draft in yab's mail page.”
Publisher declares: read-only no · destructive no · idempotent no · open-world no
8 inputs
tostringsnippetstring“One of the user's snippets, by its name: its words after body (or instead of it), {first_name} and the like filled for whom it is to, its files with it; a {{pl…”subjectstringallboolean“A reply to everyone on the thread (true) or to its sender alone (false); without it, everyone when more than two people are on it”bodystringforwardboolean“Pass the thread's last mail on to `to`, body the note above it”remind_instring“Bring the mail back to the user if nobody answers it: days after they send it ("3"), or words ("in 3 days", "friday 10am")”threadstring
“Send a mail that is in yab's mail page, only when the user asked for exactly that mail to go: the reply ready under a thread (thread: what mail_draft wrote there, or the user's own draft there, which…”
Publisher declares: read-only no · destructive yes · idempotent no · open-world yes
5 inputs
threadstringbodystring“The reply's words, when not the one ready under the thread”forwardboolean“Send the forward kept for the thread”draftstring“A new mail's draft, as mail_draft answered it (account|id)”allboolean“The reply to everyone on the thread (true) or its sender alone (false); without it, as the ready reply says”
- mail_actcreates or changes datadescribed as changing data
“Tidy a thread of the user's mail, as they would in yab's mail page: archive (out of the inbox; a thread they wait on is done waiting on too), inbox (back in), read, unread, star, unstar, spam (out of…”
Publisher declares: read-only no · destructive no · idempotent no · open-world yes
4 inputs, 2 required
untilstring“For snooze: when it comes back, ISO 8601”dostringrequiredlabelstring“For label and unlabel: the label's name, as mail_read and mail_search say it”threadstringrequired
- mail_labelscreates or changes datadescribed as changing data
“The user's own labels in their Gmail, and the list itself: list (each label with how many threads carry it), create, rename (label to `to`; the labels nested under it go with it, as in Gmail), or del…”
Publisher declares: read-only no · destructive yes · idempotent no · open-world yes
5 inputs, 1 required
labelsarray“For delete: the labels' names, all at once”dostringrequiredtostring“For rename: the new name; a slash nests it (Work/Clients)”labelstring“For create and rename: the label's name (rename: as it is now)”accountstring“The mail account, when the user has several”
- mail_recallreads or searches
“Search all of the user's mail of the last 5 years, kept on this Mac, by what it says as well as its words, for when you don't know the words the mail uses ("when does my domain renew", "what did we d…”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
5 inputs, 1 required
querystringrequiredbeforestringafterstringfromstringlimitnumber“Passages, 20 unless said, at most 40”
- mail_codereads or searches
“Read the one-time code the tab's own site mailed to the user in the last `minutes` (default 10), from their Gmail.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world yes
2 inputs, 1 required
tabstringrequired“Tab id, as `open` or `tabs` gave it”minutesnumber
“The user's Messages (iMessage and texts): with no chat, their chats, most recent first, each with its last line; with chat (an identifier from that list, a number, an address or a group's name), that…”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
2 inputs
limitnumberchatstring
“Send a message through Messages to a phone number or an address.”
Publisher declares: read-only no · destructive yes · idempotent no · open-world yes
2 inputs, 2 required
textstringrequiredtostringrequired
- messages_codereads or searches
“Read the latest one-time code from the user's Messages (texts from the last `minutes`, default 10), the user may be asked first on the tab it is for.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
2 inputs, 1 required
tabstringrequired“Tab id, as `open` or `tabs` gave it”minutesnumber
“Name this task: once it has more than one tab they sit in a folder in the user's tab list, and this is the folder's name.”
Publisher declares: read-only no · destructive no · idempotent no · open-world no
2 inputs, 1 required
namestringrequiredprogressstring“How far along, in a few words: 4 of 10, Reading reviews”
“Hand a whole browser job to an agent Yab runs itself (Claude Code, or Codex), and wait for its answer.”
Publisher declares: read-only no · destructive yes · idempotent no · open-world yes
6 inputs, 1 required
promptstringrequiredeffortstringaccessstring“browser (default): only Yab's tabs; full: request files and terminal access before the task starts (Ask/Auto ask the person; Bypass skips the question)”sessionstringclistringmodelstring
“What a task is doing now, and its answer when it is done.”
Publisher declares: read-only yes · destructive no · idempotent yes · open-world no
1 input, 1 required
sessionstringrequired
“Stop a task.”
Publisher declares: read-only no · destructive yes · idempotent no · open-world no
1 input, 1 required
sessionstringrequired
- task_steercreates or changes datadescribed as changing data
“Redirect a running task now: it reads this at its next step.”
Publisher declares: read-only no · destructive no · idempotent no · open-world no
2 inputs, 2 required
sessionstringrequiredtextstringrequired
- task_queuecreates or changes datadescribed as changing data
“Give a task something to do after what it is doing now.”
Publisher declares: read-only no · destructive no · idempotent no · open-world no
2 inputs, 2 required
sessionstringrequiredtextstringrequired
Each quoted sentence is the first sentence of the publisher’s own description. The kind of tool and the “changes data” mark are our AI model’s reading of that description, not something we tested: two differently worded runs had to agree, otherwise no label is shown, and nobody has checked them by hand. A tool without the “changes data” mark is described as only reading, searching or calculating, or the two runs did not agree. No tool was called. Read the publisher’s full description before relying on it. “Publisher declares” lists the hints the server itself sends with the tool (MCP annotations: read-only, destructive, idempotent, open-world); they are the publisher's claims, not checked by us. Inputs are the parameters in the tool's own input schema: name, declared type, whether it is required, and the first sentence of its description. Read 2026-10-23.
How well are its tools described?
Features #4 and #5
How clearly this server's own tool descriptions say what a tool does, and how consistent its tool list is. The first part is an AI model's yes/no reading of each description; the second part is counted. We do not turn it into a grade.
Descriptions
AI reading of each description
- Says what the tool does
- 100% of 69 tools
- Says what it returns
- 67% of 67 tools
- States limits, defaults or errors
- 22% of 64 tools
- Says when to use it
- 32% of 62 tools
- Items covered per tool
- 2.3 of 4 on average
Counted from the listing
- Parameters with a description
- 44% of 176
- Tools with a description
- 100% of 69
- Typical description length
- 282 characters
The tool set
Counted from the listing
- Tools
- 69
- Size of the list
- about 12,435 tokens for an agent to load (characters ÷ 4)
- Naming
- 38 of 69 names use single lower-case words
AI reading: easy to mix up
No pair found.
The AI items cover 69 of 69 tools: for a tool where two differently worded runs disagreed, that item is left out. They were not checked by hand, and no tool was called. “Easy to mix up” means two tools whose names or descriptions overlap without saying how they differ; the AI found none, comparing tools within groups of 40. We do not rate whether the tool set is complete or whether side effects are spelled out, because our AI reading of those was not reliable enough.
How do I add it to my client?
Config from the registry entry
From the npm package yab-mcp
Our sandbox started this package on 2026-10-23 (a read-only session: no tool was called).
Add to CursorAn install link in the format Cursor documents, holding the Cursor config below. The command runs the publisher’s code on your machine.
Claude Desktop · claude_desktop_config.json (Settings → Developer → Edit Config)
{
"mcpServers": {
"yab": {
"command": "npx",
"args": [
"-y",
"yab-mcp@0.2.1"
]
}
}
}Cursor · .cursor/mcp.json in a project, or ~/.cursor/mcp.json
{
"mcpServers": {
"yab": {
"command": "npx",
"args": [
"-y",
"yab-mcp@0.2.1"
]
}
}
}VS Code · .vscode/mcp.json
{
"servers": {
"yab": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"yab-mcp@0.2.1"
]
}
}
}VS Code (command line) · Bash or zsh terminal (macOS, Linux)
code --add-mcp '{"name":"yab","type":"stdio","command":"npx","args":["-y","yab-mcp@0.2.1"]}'Claude Code
claude mcp add --transport stdio yab -- npx -y yab-mcp@0.2.1
Try it in the MCP Inspector · runs on your machine, opens in your browser · Node 22.19+
npx @modelcontextprotocol/inspector@2.11.0 -- npx -y yab-mcp@0.2.1
- This runs the publisher's code on your machine (npx). Read its README first.
- The MCP Inspector lists the server's tools, resources and prompts; a tool you call there runs for real.
Built from the server's registry entry with each client's documented format (checked 2026-10-14; the Cursor link and the VS Code command 2026-10-19; the MCP Inspector command 2026-10-21). Values in < > are yours to fill in; this page never contains a key. Where the server needs a setting the entry does not declare, it can still fail to start.
Can it be installed, and is it up to date?
Version pin · advisories
Listed version
- Registry lists
- 0.2.1
- Latest stable
- 0.2.3
- Status
- behind the latest release (1 releases, 9 days)
- Withdrawn
- no
Source: registry.npmjs.org · 2026-10-23. About the version the registry lists; a manual install may resolve to a different one.
Dependency advisories
Counted in the full dependency tree as resolved on 2026-10-23 (npm audit). Bars share one scale. The package itself has no known vulnerability (OSV.dev).
Integrity, provenance, license
- Integrity
- sha512-e6yvLG2SS/d6X4BgS…
- Signature
- signed
- License
- MIT
Source: the package registry · 2026-10-22.
Usage
- Downloads
- 802 in the last month
Source: api.npmjs.org · 2026-10-22.
Does the registry listing match what we found?
Feature #6The registry verifies a package once, when it is published, and does not re-check it. A difference below is about the listing, not a judgement of the publisher.
| Registry says | We found | Result | Source · date |
|---|---|---|---|
| Published package can be started | Started and answered | matches | our test · 2026-10-23 |
| Version 0.2.1 on npm | Exists and can be installed | matches | npm · 2026-10-23 |
| Repository github.com/yetanotherbrowser/yab-mcp | Opens publicly | matches | api.github.com · 2026-10-22 |
Who made it?
Feature #7 · lineage
Facts about the publisher. We do not turn them into a trust score.
- Namespace
- com.yetanotherbrowser
- GitHub owner
- an organization (yetanotherbrowser)
- Build record
- signed
- Repository
- github.com/yetanotherbrowser/yab-mcp
- Stars
- 0
- Repository age
- 0–30 days
- Last push
- 0–30 days ago
- Archived
- no
- Security policy
- none found (we looked for SECURITY.md in the repository and in its owner’s .github repository)
Source: the registry entry and api.github.com · 2026-10-22; security policy read from GitHub · 2026-10-23.
Publish this server? Run these checks against it yourself before release, from your own machine: a server the command starts, or your own server at its URL after a one-time proof that you control it: npx protocolprobe-selftest.
Choosing
Record checks
Public records · not a safety rating7 of 9 record checks met
- #3,341 of 15,112 packages by monthly downloads, tied with 8 others
- Not ranked by stars: 0 stars (ranked from 10)
- MetRegistry entry is active and says how to run itActive, with a package or a remote address.
- MetSource repository link opensThe linked GitHub repository is public.
- MetRepository is not archivedNot archived.
- MetCode pushed to the repository in the 90 days before our checkLast push 0-30 days before our check.
- Not metRepository publishes a security policy (SECURITY.md)No SECURITY.md in the places GitHub reads it from.
- MetPackage names its licence with a standard (SPDX) identifierMIT
- MetThe version the registry lists can be installed and is not withdrawnThe listed version exists; a newer one is out.
- Not metnpm package carries build provenance (attestation)Signed by npm, but no build attestation.
- MetNo known critical or high advisory in the package or its dependenciesNone known in the package or its dependency tree.
Read from public records only: the registry entry, npm/PyPI, GitHub and advisory databases, checked 2026-10-22. No tool was called. Only “met” and “not met” are counted, so the total differs between servers; a check that does not apply or that we could not run is listed, never counted against it. It is not a safety rating. How each check works · Leaderboards
Common questions about com.yetanotherbrowser/yab
Answered from the data aboveIs com.yetanotherbrowser/yab safe to install?
We do not rate servers as safe or unsafe. 7 of its 9 applicable record checks are met (facts from public records, each listed on this page). What the records show: Its source repository opens publicly. Its repository had a push in the last 90 days. A newer stable release exists than the one listed. The package itself has no known vulnerability (OSV.dev). Its full dependency tree has no known advisory. 37 of its tools describe changing data (our AI model's reading of the descriptions). These are facts with their sources on this page, not a safety guarantee, and we did not run its tools.
Is com.yetanotherbrowser/yab free to use?
Its website (yetanotherbrowser.com/developers) describes a free pricing model. This is an AI-classified reading of the page on 2026-10-23, so check the page itself before relying on it.
Has com.yetanotherbrowser/yab been security tested?
Partly. 2 of the 12 checks that apply to it were exercised. We started the package in an isolated sandbox and read what it declares, but this test round was read-only, so its tools were not called. No security verdict is published before verification.
What can com.yetanotherbrowser/yab do?
It lists 69 tools. In our AI model's reading of their descriptions (two runs had to agree, nobody checked it by hand), they include tools that read or search, create or change data, delete, send messages, run code or commands and control a browser or desktop and more. We did not call any tool, so this describes the text, not the behaviour.
Can com.yetanotherbrowser/yab change or delete data?
37 of its tools say in their description that they create, edit, delete, send or run something (our AI model's reading). We did not call any tool, so we cannot say what actually happens.
Does com.yetanotherbrowser/yab publish a security policy?
We found no SECURITY.md in its repository (root, .github/ or docs/) or in its owner's .github repository.
Is the listed version current?
No. The registry lists 0.2.1; the latest stable release on npm is 0.2.3.
Where is the source code of com.yetanotherbrowser/yab?
In github.com/yetanotherbrowser/yab-mcp, which opens publicly.
Found this page useful?
Anonymous · no sign-inA quick, anonymous reaction — no account, no email. One per kind from your browser. The tally updates when the page is next refreshed, and it is only a rough count, never a safety rating or a measured number of people.
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- io.github.LinVireo/browsertap-mcpBrowserTap MCPalso has tools that controls a browser or desktop, creates or changes data, deletes, runs code or commands, reads or searches, sends messagescompare with this one
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Active servers whose topic is also “search-and-web-data” and that have at least one tool of the same kind; most kinds in common first, then most GitHub stars. The topic and the tool kinds are an AI model's reading of the publishers' descriptions, not checked by hand. Similar is not a recommendation.
Compare with another server
Side by side: registry entry, our read-only session, the tools and the 18 classification fields. Same values as each page; no score.
Security testing
What did we test, and what did we leave out?
18 checks · features #1, #2
Not probed (read-only run)
We started the package in an isolated sandbox and read what it declares, but this test round was read-only, so its tools were not called. No security score is given; a check we did not run is never counted as passed.
- Inventory: exercised
- Hidden instructions: exercised
- Real execution: not run · our policy
- Secret leak: not run · nothing to check it against
- Internal addresses: not run · our policy
- Unconfirmed changes: not run · our policy
- Bad input: not run · our policy
- Model requests: not run · nothing to check it against
- Sensitive questions: not run · nothing to check it against
- Folder boundary: not run · our policy
- Log leaks: not run · nothing to check it against
- Hidden content: not run · nothing to check it against
- Fake assistant turns: not applicable
- Token passthrough: not applicable
- Token audience: not applicable
- Sign-in redirect: not applicable
- Consent handling: not applicable
- Sign-in metadata: not applicable
2 exercised10 not run (reason given)6 not applicable
Each check ends in exactly one state: exercised, not run (with the reason), or not applicable (with the reason). 2 of the 12 checks that apply to it were exercised. We do not publish security-check outcomes for named servers.
- 1Inventory
tool-listReads the declared tools, resources and prompts.exercised - 2Hidden instructions
description-poisoningLooks for hidden instructions in tool descriptions.exercised
- 3Real execution
real-executionCalls a tool and checks what really happens.This check calls the package's tools. This test round was read-only, so no tool was called; tools can act on outside services with the publisher's or a user's account.not run · our policy - 4Secret leak
canary-leakPlants a fake secret and checks whether it leaks.This check needs at least one successful tool call to have something to check, and no tool was called.not run · nothing to check it against - 5Internal addresses
ssrfChecks whether a tool can be steered to internal addresses.This check calls the package's tools. This test round was read-only, so no tool was called; tools can act on outside services with the publisher's or a user's account.not run · our policy - 6Unconfirmed changes
write-without-confirmationChecks whether tools that change data act without asking.This check calls the package's tools. This test round was read-only, so no tool was called; tools can act on outside services with the publisher's or a user's account.not run · our policy - 7Bad input
error-handlingSends bad input and watches how the server answers.This check calls the package's tools. This test round was read-only, so no tool was called; tools can act on outside services with the publisher's or a user's account.not run · our policy - 8Model requests
samplingChecks whether the server asks the client's model to act for it.This check needs at least one successful tool call to have something to check, and no tool was called.not run · nothing to check it against - 9Sensitive questions
elicitation-sensitive-dataChecks whether the server asks users for sensitive data.This check needs at least one successful tool call to have something to check, and no tool was called.not run · nothing to check it against - 10Folder boundary
root-boundaryChecks whether the server reaches outside the folders it was given.This check calls the package's tools. This test round was read-only, so no tool was called; tools can act on outside services with the publisher's or a user's account.not run · our policy - 11Log leaks
logging-side-channelChecks whether log messages carry data they should not.This check needs at least one successful tool call to have something to check, and no tool was called.not run · nothing to check it against - 12Hidden content
audience-hidingChecks resources that hide content from the user.This check needs content the server returns, and nothing was read or called.not run · nothing to check it against
- 13Fake assistant turns
fake-assistant-turnChecks prompts that pose as the assistant's own words.The server exposes no prompts.not applicable - 14Token passthrough
token-passthroughChecks whether the server forwards a user's token to other services.The server runs locally over standard input/output, so there is no sign-in flow to check.not applicable - 15Token audience
token-audience-validationChecks whether tokens meant for another service are accepted.The server runs locally over standard input/output, so there is no sign-in flow to check.not applicable - 16Sign-in redirect
open-redirectChecks the sign-in redirect for abuse.The server runs locally over standard input/output, so there is no sign-in flow to check.not applicable - 17Consent handling
confused-deputyChecks consent handling when one service acts for another.The server runs locally over standard input/output, so there is no sign-in flow to check.not applicable - 18Sign-in metadata
oauth-url-schemeChecks the published sign-in metadata for unsafe URLs.The server runs locally over standard input/output, so there is no sign-in flow to check.not applicable
Source: our own test in an isolated sandbox, 2026-10-23, mcp-runtime-engine@0.1.0. Which checks count and why follows our published scoring model.
What happened during the test?
Feature #8
The steps in order, as the test record holds them.
- 0 msStarted the published package in an isolated sandbox (read-only mode)
- 1,529 msConnected after 0 redirects.
- Read the inventory: 69 tools, 0 resources, 0 prompts.
- 2,571 msFinished: 2 checks exercised.
Reference
How is it classified?
18 fields
One value per field, each with its source. Fields written by AI models are marked. A field with no value says why.
“Free, for macOS 15.4 or later. Version 0.35.5”
“Not stated” means the source did not state it; “does not apply” means it does not apply to this kind of server; “our limit” means our own lookup failed. A linked value opens the directory filtered to the same value.
Cite or correct this page
Sources and corrections
Suggested citation
ProtocolProbe. “com.yetanotherbrowser/yab: MCP server record.” Data checked 2026-10-23. https://protocolprobe.com/mcp/servers/com.yetanotherbrowser/yab
Figures are valid for the date shown. Our facts on this page are CC BY 4.0: reuse them with a link and the check date. Quoted text (the publisher’s descriptions, website quotes, tool names) is not ours to license.
As JSON: this record in the API · API documentation.
Badge for your README
[](https://protocolprobe.com/mcp/servers/com.yetanotherbrowser/yab)
It shows this server's record-check count: facts from public records, no tool called. It is not a security rating or a pass. It links here and updates after each data reload.
Something wrong, or is this yours?
If a fact here is wrong, tell us and we will re-check it. If you operate this server, you can run our checks on it yourself with the free self-test command; we call no server’s tools ourselves for anything shown here.
Write to hello@protocolprobe.com · corrections log · methodology