> ## Documentation Index
> Fetch the complete documentation index at: https://open-index.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Connectors

> Pull entities from someone else's MCP server into your brain on a schedule.

Everything in [Open Index as a context layer](/agents/mcp) is about exposing **your
brain** over MCP. A *connector* is the reverse: a script in
`<brain>/connectors/*.py` that calls **someone else's** MCP server and turns the
results into entities.

```python theme={null}
from open_index.connectors import Connector, EntitySpec


class LinearConnector(Connector):
    name = "linear-issues"

    # Where the source MCP server lives. ${ENV} refs are resolved at run time,
    # so the URL and token stay out of git.
    mcp_url = "${LINEAR_MCP_URL}"
    mcp_auth_headers = {"Authorization": "Bearer ${LINEAR_TOKEN}"}

    schedule = "daily"          # manual | hourly | daily | weekly | 6h | 30m | 1w

    def extract_issues(self):
        for item in self.paginate("list_issues", result_key="issues"):
            yield EntitySpec(
                doc_type="issue",
                id=f"issue:{item['id']}",
                name=item["title"],
                fields={"status": item["state"]},
                related_to=[(f"product:{item['project']}", "belongs to product")],
            )
```

## Where do you get `mcp_url`?

From whoever runs that server:

* A hosted vendor MCP server — from their docs (e.g. `https://mcp.vendor.com/mcp`).
* Another Open Index brain — its `open-index serve` URL, i.e. `http://host:8080/mcp`.
* A local stdio-only MCP server — **not supported here.** Connectors speak
  streamable HTTP/SSE over `httpx` only. It needs an HTTP endpoint.

<Note>
  The URL must be the full endpoint path — the same one an agent would use.
</Note>

## Running connectors

```bash theme={null}
export LINEAR_MCP_URL=https://mcp.linear.app/mcp
export LINEAR_TOKEN=...

open-index list-connectors                  # what's discovered, and its URL
open-index ingest linear-issues             # run it now
open-index run                              # run everything whose schedule is due
open-index run --loop 3600                  # or wire `open-index run` into cron/CI
```

`open-index run` tracks last-run times in a gitignored `.open_index_state.json`, so
it decides *whether* a connector is due — your cron drives the clock.