Maps in agent-built pages: options after reverting export_map_html_tool #281

Problem

An agent building a site or file with a map (ChatGPT/Codex, Claude Code, Claude artifacts) has to write its own Mapbox GL JS code and ask the user for a public token. That's what happened in ChatGPT/Codex when someone asked for a site with a map. render_map_tool only renders inside the chat as an MCP App, so it doesn't help here.

#275 (export_map_html_tool) tried to solve this and was reverted in #279. The work is kept on feat/export-map-html-tool. This issue is for picking the approach before building again.

A page needs three things:

1. map code (GL JS)
2. a public token
3. the data (routes, places, isochrones)

The data mostly works today: tools already return GeoJSON, and refs can be refetched (directionsRequestFromRef, #276). The real gap is the token, and how much code we hand the agent.

Options

1. Public token tool in this server (get_public_token_tool or similar)

Returns the account's default public token, using the same resolveMapboxPublicToken() the in-chat map already uses (pk passthrough, /tokens/v2/{user}?default=true with tokens:read, or MAPBOX_PUBLIC_TOKEN). The agent writes its own GL JS.

• Pros:
  • Small, and needs no new OAuth scope.
  • Fits any framework (plain HTML, React, Next).
  • It's what a developer does by hand.
  • pk tokens are meant to be public, and this one already ships to every in-chat map page.
• Cons:
  • The default public token has no URL restrictions. Once it's in a published site or a public repo, anyone can reuse it and the usage bills to the user's account.
  • A tool that returns a credential may get extra attention in the Claude connector directory and ChatGPT app reviews.
  • The agent still writes GL JS from scratch, so quality varies.
• Mitigations:
  • The result says plainly that this is for local or prototype use, and that a published site should use a URL-restricted token, with a link to create one.
  • Never return secret or temporary tokens; pk only.

2. Point site building at the devkit server

mcp-devkit-server already has list_tokens_tool and create_token_tool, which can create a URL-restricted token. The server instructions here would say that site building is a devkit task.

• Pros:
  • Proper scoped tokens, and no credential tool in the consumer server.
• Cons:
  • It needs a second server installed.
  • create_token_tool needs tokens:write, a much bigger grant.
  • Most ChatGPT and Claude users won't have devkit.

3. Re-land export_map_html_tool

A whole page, with data and token baked in and the script pinned on jsDelivr.

• Pros:
  • The best one-shot result for "make me a page with this map".
• Cons:
  • It's what was reverted.
  • It ties us to a public hosted script contract and the npm/jsDelivr release cycle.
  • It hands over a whole document, which fits poorly into an existing app or framework.
  • It has a 200 KB data cap.
  • The token concern from option 1 still applies, because the token is inside the page.

4. An embed snippet tool (middle ground)

Returns a small GL JS snippet or config (style, layers, markers) plus the token, for the agent to drop into its own page, instead of a full document.

• Pros:
  • Reuses our layer and marker logic.
  • Fits existing pages.
• Cons:
  • It's still a code-generation contract to maintain.
  • The token concern is the same as option 1.

5. Static map URLs

For pages that don't need interaction, return a Static Images API URL (with the public token) that the page can use as an <img>.

• Pros:
  • Trivial to embed, and no JS.
• Cons:
  • Not interactive.
  • The URL still carries the token.

6. Do nothing; document it

Server instructions tell the agent to ask the user for a public token and link to account.mapbox.com.

• Pros:
  • No new surface.
• Cons:
  • The friction that started this.

Questions to settle

• Is returning the default public token to the model acceptable, given it's already embedded in every in-chat map? Or do we require a URL-restricted token for anything that leaves the chat?
• Should the consumer server have any credential-returning tool, given connector directory review?
• Do we want to own any page or snippet code (options 3 and 4), or leave GL JS to the agent plus docs (mcp-docs-server)?

Leaning

Option 1, scoped tightly:

• pk only, from the existing resolver.
• Read-only, no new scopes.
• The result says to use a URL-restricted token for published sites.
• Paired with docs for the GL JS side.

Option 2 stays the path for people who want proper scoped tokens. Options 3 and 4 can come back later if agents' hand-written maps turn out to be poor.