Leadbay MCP for Claude
Give Claude (Desktop, Code, and Cowork) direct access to your Leadbay account. Once installed, Claude can pull leads, qualify them, enrich contacts, log outreach — all using your real data, with your permissions.
This guide covers installation in Claude Cowork via the prebuilt .mcpb extension. Other clients (Claude Desktop, Cursor, Claude Code) are covered in the Leadbay MCP README.
The MCP server is open source and lives at github.com/leadbay/leadclaw. It uses your Leadbay account, so any action Claude takes is the same as if you'd done it yourself in the app.
What you'll need
A Leadbay account (sign up here if you don't have one)
Claude Cowork (or any Claude client that supports MCP extensions)
One minute
Step 1 — Download the latest extension
Open the LeadClaw releases page and grab the latest .mcpb file (look for a name like leadbay-X.Y.Z.mcpb under the most recent release's Assets).
Save it somewhere easy to find — your Downloads folder works.
Step 2 — Install the extension in Cowork
In Claude Cowork, go to:
Settings → Extensions → Advanced → Install extension
Pick the leadbay-X.Y.Z.mcpb file you downloaded in Step 1.
A dialog opens with the extension details. Click Install, then confirm with Install again.
Once installed, toggle the extension to Enabled.
Step 3 — Sign in with Leadbay
The first time Claude calls a Leadbay tool, it triggers a one-tap Sign in with Leadbay flow:
A Leadbay login page opens in your browser
Log in (or confirm your existing session)
Click Approve to grant Claude access to your account
The browser tab closes itself and Claude continues the conversation
That's it — no tokens to mint, copy, paste, or rotate. The connection is scoped to your account and you can revoke it anytime from Settings → Connected apps in Leadbay.
If you have access to both the US and EU instances of Leadbay, sign in on the instance you want Claude to use. You can switch later by signing out from the Leadbay extension in Cowork and signing back in on the other instance.
Step 4 — Allow the tools
Leadbay ships two flavors of tools:
Read-only
Pulls leads, lenses, profiles, contacts, taste profile, enrichment quota — never changes anything
Always allow
Write / delete
Qualifies leads, enriches contacts, adds notes, imports leads, reports outreach, refines audience
Always allow
Both flavors are safe to always-allow because the Leadbay MCP is scoped to your account — there's nothing destructive at the platform level. Setting both to "always allow" makes Claude flow without interrupting you for permission on every call.
To configure: in the Leadbay extension's Configure screen, set Always allow for both the read-only tool group and the write/delete tool group.
Try it
Open a Cowork conversation and ask:
Pull today's top leads and tell me which two are worth opening this morning.
Claude will call leadbay_pull_leads, leadbay_get_lead_profile, and friends — and reply with a short, qualified shortlist.
A few more prompts that work out of the box:
Research acme.com — is it a fit for us?
Refine my audience to focus on EU companies hiring sales reps.
I just emailed Jane at Acme. Log it as outreach.
The full list of tools and recommended workflows is in the LeadClaw README.
Updating
When a new release ships, repeat Step 1 (download the new .mcpb) and Step 2 (Install extension). Cowork replaces the old version in place; your sign-in stays valid, so you don't need to re-authenticate.
Using Leadbay with Claude Desktop
Claude Desktop is slower than Cowork to load MCP tools, so a couple of extra precautions help.
After installing the Leadbay extension, fully quit and relaunch Claude Desktop (Cmd-Q on Mac, then reopen — not just closing the window). Open a new chat and wait about 30 seconds before sending your first message. This gives Claude time to load the Leadbay tools.
If your first message gets a response like "I don't see any Leadbay tools" or "I can't find Leadbay in your setup", don't worry — the tools are still loading. Send any second message (even just "try again") and Claude will pick them up. From that point on, the rest of your session works normally.
Troubleshooting
Claude says "not authenticated" or 401 errors
Your sign-in may have expired or been revoked. Trigger any Leadbay tool again and Claude will re-prompt the Sign in with Leadbay flow
Tools don't appear in Cowork
Make sure the extension toggle is Enabled in Settings → Extensions
Tools appear but Claude won't call them
Open Configure and switch the tool groups to Always allow
Wrong instance (no leads / 404s)
Sign out from the Leadbay extension and sign back in on the right instance (US or EU)
Other issue
File a bug at github.com/leadbay/leadclaw/issues
Last updated