MCP server

ZeroWidth ships a Model Context Protocol server at https://api.zerowidth.ai/mcp. Wire it into Claude Code, Cursor, Codex, Claude Desktop, or any MCP-compatible host and the LLM gains tools that search our docs and — with a personal access token — drive your workspace's flows, datasets, evals, and pages.

Coding agents are where this pays off most: the agent writing the integration can read the reference for it, list the flow it's about to call, and check the scope its key needs, without you leaving the editor.

Two classes of tools, one endpoint

The same /mcp URL serves both:

• Docs tools — search_docs, get_doc, list_docs. No authentication required. Work the moment you paste the URL into your MCP client.
• Platform tools — workbench_flows_list, caliper_datasets_list, compass_pages_list, ledger_entries_list, napkin_boards_view, … Require a bearer token (personal access token or workspace API key) carrying the right scope. Acts with your permissions across every workspace you're a member of.

Try the docs first to see if it's installed correctly; add a token when you want the platform layer too.

Docs tools (no auth)

Three tools, covering everything published in these docs:

Every doc page is also registered as an MCP resource under docs://<slug> — hosts that surface MCP resources (Claude Desktop's "Attach from MCP" UI, certain Cursor flows) let the user browse the list and pull pages into context without an LLM tool call.

Platform tools (authenticated)

With a bearer token, the LLM gets tools that drive your workspace. Each requires a scope; a _list/_get/search tool needs the matching :read, a create/run/edit tool needs :write (or :run).

The tables below are the ones worth knowing by name, not the whole set — every product surface has more, and your client lists what your token can actually reach. If you want the full picture, ask your client to list its tools once you're connected.

Workbench

Caliper

Compass

Ledger

Napkin

Prism

A token can never do more than you can. Its scopes set the maximum, and your role in each workspace applies on top — a token with caliper:evals:write can't write in a workspace where you're a member rather than an admin.

Mint a personal access token at accounts.zerowidth.ai → Integrations. Tokens are bound to you, expire on a schedule you choose (default 90 days), and revoke instantly from the same page.

Connect to one product

/mcp lists the tools for every product. If you only work in one, connect to that product's URL instead. Your client sees a shorter list, and the model picks the right tool more often.

Each one also includes the tools that work across products: workspace search, tags, comments, and the docs tools.

Add /readonly to any product URL to list only the tools that read. For example, https://api.zerowidth.ai/mcp/x/ledger/readonly can look up entries and metrics but can't create or change anything.

Tool names are the same on every URL, and the same token works on all of them. To use two products, add each one as its own server in your client, or keep using /mcp.

Setup

1. 1
   (Optional) Mint a personal access token

   Go to accounts.zerowidth.ai → Integrations → New token. Pick a name (where you'll paste it), pick scopes (start broad with full_access if you're not sure), pick a default workspace (lets you skip the workspace arg on most calls), confirm. Copy the token immediately — it's shown exactly once.

   Skip this step if you only need the docs tools.

2. 2
   Add the server to your MCP client's config

   Claude CodeCodexCursor, Claude Desktop and most others

   One command, from anywhere in your project:

   claude mcp add --transport http zerowidth \
     https://api.zerowidth.ai/mcp \
     --header "Authorization: Bearer $ZEROWIDTH_TOKEN"

   Drop the --header flag for docs-only (anonymous) access. Your shell fills in $ZEROWIDTH_TOKEN before Claude Code sees the command, so the token itself is saved to your local Claude Code config. Add --scope user to use the server in every project, not just this one.

   To share the server with everyone on a repo, commit a .mcp.json at the repo root instead. Don't use --scope project with the command above: it writes your actual token into that file. Claude Code reads ${ZEROWIDTH_TOKEN} from each person's environment when it connects, so the file holds only the variable name:

   {
     "mcpServers": {
       "zerowidth": {
         "type": "http",
         "url": "https://api.zerowidth.ai/mcp",
         "headers": {
           "Authorization": "Bearer ${ZEROWIDTH_TOKEN}"
         }
       }
     }
   }

   claude mcp list health-checks the connection.

3. 3
   Restart the client

   Desktop hosts like Claude Desktop and Cursor only re-scan their config on startup — quit fully and re-open, and the zerowidth server appears in the tools menu. Terminal agents pick it up on the next session: start a new claude or codex and ask it what tools it has.

4. 4
   Try it

   Without a token, the docs tools are available. Ask:

   How do I run a Workbench flow from my code?

   The LLM should call search_docs and then get_doc, then summarize from the returned Markdown.

   With a token, the platform tools light up too:

   List my Workbench flows in the acme workspace.

   The LLM calls workbench_flows_list with workspace: "acme" (or omits it if the token has a default workspace).

Troubleshooting

Security

• Tokens are shown exactly once at mint — copy immediately. Lost tokens can't be recovered, only revoked + reminted.
• Tokens always expire — pick up to 365 days, 90 by default.
• Optional IP allowlist at mint time restricts where the token can be used from. Recommended for service hosts; skip for laptops on changing networks.
• Revoke instantly from accounts.zerowidth.ai → Integrations; the revoke takes effect on the token's next call.
• Every call lands in your workspace's audit log under your name.