Codex Gsfa MCP Server

@pipeworx/codex-gsfa

The FAO/WHO Codex General Standard for Food Additives (GSFA, CXS 192-1995) — which food additives may be used in which foods, at what maximum level, under which conditions.

Part of Pipeworx — an MCP gateway connecting AI agents to 1663+ live data sources.

Tools

Two kinds of permission

GSFA grants use in two structurally different ways, and every provision returned says which one it came from:

• Table 1 & 2 (provision_table: "table1_2") — a specific maximum use level, either numeric (10,000 mg/kg) or GMP, usually conditioned by numbered notes.
• Table 3 (provision_table: "table3") — the additive is permitted under good manufacturing practice with no numeric limit.

For methyl cellulose that is 17 Table 1/2 provisions against 61 Table 3 ones. Treating them as one thing either invents limits the standard does not set or hides most of where an additive is actually allowed.

Subcategory inheritance

A GSFA provision applies to the food category named and all of its subcategories — a provision on 01.4 also governs 01.4.4. Lookups walk up the numbering and report inherited_from_parent plus matched_food_category, because "permitted at this level for this exact food" and "permitted because its parent category is" are different answers.

permitted: false means the standard lists no provision. That is not the same as an explicit prohibition, and the response says so rather than implying a ban.

Notes are part of the answer

Provisions are frequently qualified by numbered notes — "for use in ready-to-drink products only", "as sulphur dioxide", "on the fat basis" — and a maximum level is not fully specified without them. 2,590 of 15,377 provisions carry one.

Note text is inlined on every provision (notes: [{id, text}]), not left as a bare id, because an id with no text invites a caller to read the level and stop. gsfa_notes resolves ids directly or searches note wording.

The text is scraped from the note icon's tooltip on each additive page, so it carries the same Codex session as the additive it qualifies. All 468 cited note ids resolve.

Auth

None. The dataset ships inside the pack.

Freshness

Every additive result carries cac_session, cac_year, and snapshot_date. Records come from archived snapshots of GSFA Online, so individual additives can lag the newest Codex session — gsfa_coverage reports which sessions are present and which additive ids could not be retrieved at all (entries whose every archived snapshot is one of FAO's own error pages).

Regenerate with:

node --experimental-strip-types scripts/ingest-gsfa.ts

Data sources

• Codex GSFA Online — https://www.fao.org/gsfaonline/ (FAO fronts this with a Cloudflare managed challenge; we read Internet Archive snapshots instead — see docs/codex-gsfa-plan.md for the route and the freshness plan)
• Codex Alimentarius CXS 192-1995 — https://www.fao.org/fao-who-codexalimentarius/codex-texts/dbs/gsfa/en/
• JECFA specifications and evaluations, which GSFA links to for toxicological data — https://apps.who.int/food-additives-contaminants-jecfa-database/

Quick Start

Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):

{
  "mcpServers": {
    "codex-gsfa": {
      "url": "https://gateway.pipeworx.io/codex-gsfa/mcp"
    }
  }
}

What this endpoint actually serves

tools/list at https://gateway.pipeworx.io/codex-gsfa/mcp returns the tools in the table above plus the shared Pipeworx meta-tools — ask_pipeworx, discover_tools, search_within, remember/recall and the rest of the gateway-wide set. So the tool count you see is larger than this table: a single-pack endpoint currently lists roughly 30 shared tools alongside the pack's own. The connection's initialize response states its exact scope, and is the authoritative answer for a given day.

This is deliberate, not multiplexing by accident. The meta-tools are what let a scoped connection answer a question this pack does not cover — via ask_pipeworx, which routes across the whole catalog — without you adding a second MCP server. There is currently no way to mount a pack endpoint without them; if the extra schemas cost you more context than the routing is worth, connect to the full gateway once rather than to several pack endpoints.

Or connect to the full Pipeworx gateway to get every pack's tools listed directly, instead of just this one's:

{
  "mcpServers": {
    "pipeworx": {
      "url": "https://gateway.pipeworx.io/mcp"
    }
  }
}

Both URLs reach the same gateway and the same 1663+ data sources. The only difference is which pack's tools are listed directly; ask_pipeworx reaches all of them from either one.

No MCP client? Call it over HTTP

curl -X POST https://gateway.pipeworx.io/v1/tools/gsfa_check_use \
  -H 'Content-Type: application/json' \
  -d '{"additive":"461","food_category":"14.1.5"}'

No account needed for the first calls. Inspect any tool: GET https://gateway.pipeworx.io/v1/tools/gsfa_check_use. Find one: POST https://gateway.pipeworx.io/v1/tools/search_packs with {"query":"..."}.

Standalone (no gateway account)

This package also runs as a local stdio MCP server — no Pipeworx account, no gateway round-trip:

{
  "mcpServers": {
    "codex-gsfa": {
      "command": "npx",
      "args": ["-y", "@pipeworx/mcp-codex-gsfa"]
    }
  }
}

Or run it directly to confirm it starts:

npx -y @pipeworx/mcp-codex-gsfa

It speaks MCP over stdin/stdout and answers initialize/tools/list/tools/call for only this pack's tools — none of the shared meta-tools the gateway connection above adds. Same source, same tools, no ask_pipeworx routing.

Using with ask_pipeworx

Instead of calling tools directly, you can ask questions in plain English — this works on the pack endpoint above as well as on the full gateway:

ask_pipeworx({ question: "your question about Codex Gsfa data" })

The gateway picks the right tool and fills the arguments automatically.

More

• Docs and guides
• pipeworx.io

License

MIT