Use Foldr with Haystack (MCP)
Haystack is deepset's open-source LLM framework focused on production RAG and search pipelines, heavily used by enterprise NLP teams. Haystack's `MCPToolset` component wraps any MCP server as a pipeline tool. Foldr is useful when a Haystack pipeline produces a report and needs to hand it off as a public URL.
Installation
Add the Foldr MCP server to Haystack with the snippet below. Replace fs_… with an API key from foldr.space/developers/signup. Each upload costs 5¢ - top up account credits or subscribe to Pro tier to bypass per-call charges.
pip install haystack-mcp
# Python
from haystack_integrations.tools.mcp import MCPToolset, StdioServerInfo
toolset = MCPToolset(server_info=StdioServerInfo(
command="npx", args=["-y", "@foldr/mcp-server"],
env={"FOLDR_API_KEY": "fs_live_..."}
))What You Can Do
- Upload any file from Haystack to Foldr and get a permanent shareable URL back in the same turn (5¢ per upload, debited from credits)
- Mint short-lived capability tokens to share files with downstream agents without leaking your API key
- Organize uploads into per-API-key folders with hierarchical structure
- Shorten long URLs to foldr.space/s/... links - free with any API key
- Wire Foldr tools into any existing Haystack agent with a few lines of config
Haystack + Foldr FAQ
How do I install the Foldr MCP server in Haystack?
Open Haystack's MCP configuration (the CLI) and paste the config block shown above. Set FOLDR_API_KEY to a key you create at foldr.space/developers/signup. Restart Haystack if it doesn't hot-reload.
How much does it cost to use Foldr from Haystack?
Each upload costs 5¢. You can pay by topping up account credits via the `top_up_credits` MCP tool (min $5) - every upload then debits from balance. Or subscribe to Pro tier ($25/mo) and per-call charges are bypassed entirely. Tools that don't write data (list_files, mint_capability, get_usage, etc.) are free.
I set the key but Haystack says the Foldr tool isn't available - what's wrong?
Three common causes: (1) Haystack wasn't restarted after editing the config - most MCP hosts need a restart to pick up new servers. (2) The API key is wrong or missing - verify the env var name your client reads (e.g. FOLDR_API_KEY) matches the config snippet above. (3) Your client doesn't support the streamable-http transport - most modern clients do, but check Haystack's docs for the version that added MCP support.
Can Haystack upload files directly to Foldr, or just generate URLs?
Haystack can do both. The MCP server exposes tools for `upload_file` (base64-encoded file content), `bulk_upload` (up to 20 files in one call), `mint_capability` (short-lived shareable links), and `create_short_url`. Any file Haystack can read from disk can be uploaded.
Is the Foldr MCP integration with Haystack production-ready?
Foldr's MCP server is stable and used in production - streamable-http transport at https://foldr.space/api/mcp with 23 tools. Haystack's MCP support is currently in public beta - suitable for day-to-day use. Every write endpoint accepts an Idempotency-Key so retries are safe.
Related MCP Integrations
Connect Haystack to Foldr in under a minute
Grab an API key, paste the snippet above into Haystack's MCP config, top up credits (or grab a Pro subscription), and your agent can upload files and mint share links immediately.