Cobalt MCP server

• add_noteFree

  Append a free-standing text note (not tied to a screenshot) to a review created by create_review. Use for context, steps taken, or a summary of findings between screenshots.

• add_screenshotFree

  Append a screenshot (with an optional note) to a review created by create_review. The image is stored durably in Cobalt — this is the way to persist screenshots that would otherwise be lost when they only pass through a browser tool. Call once per screen as you go. NO BROWSER? Pass `page_url` and Cobalt renders the page for you (Cloudflare headless Chrome): `viewport` 'desktop' (1280px) or 'mobile' (390px phone, 2x), `full_page` true for the whole scroll. Use it for every screen you would otherwise only describe in text — a review without screenshots is a reduced deliverable, and the mobile viewport is how you test the phone fold without a device. The result includes the rendered image: LOOK AT IT before moving on. Cookie walls and modal veils are stripped automatically, but if what came back is still not the shot (an overlay, a blank, the wrong page), retake it in place with `replace_item` = that item's number, adding `hide_selectors` for anything you can name — never leave a useless capture in the review and never append a second copy after it. Otherwise the input is `image_url`: POST the image to https://cobaltcapture.com/api/upload (multipart field `file`, no auth, returns {url, key}) and pass back the url. If a browser-automation script took the screenshot, do that POST inside the same script (Python `requests.post(...)`, or Playwright's request context) rather than shelling out to curl afterwards — same result, one less permission prompt. The `image` base64 parameter exists for small images only: tool-call arguments are model-generated text, so a real screenshot means emitting tens of thousands of base64 tokens perfectly, and an image you received as an image cannot be transcribed at all.

• check_inboxFree

  Read mail delivered to an inbox from create_inbox — e.g. to pull a verification code or confirmation link out of a signup email. Returns newest-first. Mail usually lands within seconds; if the response is empty, wait a few seconds and call again (there is no blocking wait). Extract the code or link yourself and continue the flow in the browser. Pass format="html" when you are AUDITING the email rather than reading a code out of it: the default text view flattens away the layout, typography and branding, which is exactly what an email audit is judging.

• create_inboxwrite actionFree

  Create a disposable email inbox you can monitor, for signing up to the product you're testing. Returns an `address` to type into the signup form and an `inbox_token` to read it with. Use this instead of asking the human for an email account or a third-party inbox API key — no setup needed. Inboxes are temporary; create a fresh one per test persona.

• create_reviewwrite actionFree

  Start a new Cobalt Capture review and get a handle for filling it in. Use this to compile the findings of any site study — a usability pass, a pricing teardown, a positioning audit, a QA run — into one shareable, durable report with real screenshots. Works from any client, chat assistants included: with no browser, add_screenshot(page_url=...) renders the pages for you. Returns a `review` slug and a `claim_token` — pass BOTH back to add_screenshot / add_note to append content. Also returns a `review_url` to share and a `save_url` the human opens (while signed in) to save the review to their account permanently. The review is anonymous and auto-deletes after 30 days unless saved.

• email_reviewwrite actionFree

  Email a link to a finished review to the human who started the run, so they don't have to remember to come back for it — useful at the end of a long unattended study. Pass the review, its claim_token, and the human's email. IMPORTANT: we only send to a VERIFIED COBALT ACCOUNT address (this prevents the tool being used to send spam); if the address isn't a Cobalt account, the call is refused with a message telling the human to create a free account at cobaltcapture.com with that address first. The email contains only a link to the review — no text you provide — so ask the human for their account email and pass it verbatim.

• fetchFree

  Fetch the full text of a Cobalt study by the id search returned, or of any Cobalt review by its URL (/r/<slug>) or slug. Returns text: findings, prices, the comparison matrix, and the underlying review's notes with links to its screenshots. Use get_review instead when you need to see the screenshots as images.

• get_playbookFree

  Fetch a Cobalt study playbook by name and follow it exactly. Works from ANY client — a coding agent driving a browser, or a chat assistant with no browser (Claude chat, Cowork, ChatGPT): the public-page studies run in full from chat, because add_screenshot(page_url=...) renders the pages for you. Use this when the user asks for any kind of site review, audit, teardown, or test and you don't already have the playbook text. Available: 'pricing_teardown' — can a buyer tell what they'd pay and which tier is theirs (public pages: runs anywhere); 'positioning_pass' — positioning and messaging audit of the public site (public pages: runs anywhere); 'comparison_study' — two or three products compared for one buying decision, with a sourced matrix and an overall lean (public pages plus web search: runs anywhere); 'usability_pass' — first-time-user usability audit: signs up with a disposable inbox, drives the product, finds friction (needs a browser you control); 'flow_pass' — walks a specific flow the user names, signup/checkout/invite, including any email it sends (needs a browser you control); 'investigation_pass' — the general product investigator for an app you OWN, run in its own environment (needs a browser and usually the repo). All deliver a shareable Cobalt review. If the user's study is NONE of these, do not bend it into the nearest one — its lenses and severity labels will mislabel the findings; run the generic method in the server instructions instead. Prefer this over fetching the playbook from a URL: it comes through the protocol complete, whereas web fetchers summarize it and a summarized playbook silently drops the instructions that make the run work.

• get_reviewFree

  Fetch a Cobalt Capture review by its share link or slug. Returns the reviewer's notes as text AND each annotated screenshot as an image, so you can see exactly what was marked and what to change.

• searchFree

  Search the studies Cobalt Capture has published on well-known products: pricing teardowns, positioning audits, and head-to-head comparisons (for example Canva pricing, Spotify vs Apple Music). Returns matching studies as {id, title, url}; pass an id to fetch for the full text. It does NOT search private reviews, which are reachable only by their link (use get_review, or fetch with the review URL).

• update_reviewwrite actionFree

  Update a review's summary and/or title after the fact. Use this at the END of a run to land the verdict at the TOP of the review: the headline findings don't exist until the work is done, but readers (and agents ingesting the review) want them before scrolling past every intermediate screenshot. Prefer this over burying conclusions in a closing note.

• –Code scanremote-only server, no package to scann/a
• Live reliabilityremote reachable in 503ms20/20
• Tool poisoning11 tool descriptions checked15/15
• Auth qualityopen endpoint exposes 4 write-action tools with no auth3/15
• Maintenanceno repository listed3/15
• Maintainer identityverified namespace with website, no repo4/10

Cobalt: common questions

Is Cobalt MCP server safe?

With care: it is graded C, so read the findings first (60/100). Read the Cobalt safety report

How do I install Cobalt?

It runs remotely at cobaltcapture.com. Add it to Claude Code, Claude Desktop or Cursor with the snippets above, or call it through the mcp.market gateway without installing anything.

Does Cobalt need an API key?

Not as far as the registry entry and our scan can tell: no credentials are declared or required.

Is Cobalt maintained?

The latest release is v1.16.0.

Is Cobalt up?

100% of our last 6 checks got an answer. We check remote servers about four times a day.

What can I use instead of Cobalt?

Servers from other publishers that do the same job: Squad MCP server, COTAL actions (cotal.ai) MCP server and HasData Walmart MCP server. Compare all Cobalt alternatives.