# The AsOf connector for Claude

Ask Claude who ran a company on a given day, what it reported, what changed since, or which AI model is the latest, and get the answer from a record in which every value is dated and sourced.

AsOf keeps facts about tech and AI companies, the people who run them, their products and AI models. Every value carries the day it took effect and the source that states it, and a value that changes is closed with an end date and kept. The connector is a remote MCP server: Claude, or any MCP client, reads the record while it answers and can cite the source and the as-of date for each fact.

## Add it to Claude

[AsOf in Claude's connector directory](https://claude.ai/directory/asof)

1. Open AsOf in Claude's connector directory and add it. There is nothing to sign in to.
2. Open a chat, turn AsOf on in the tools menu, and ask a dated question. Every tool only reads the record, so Claude can be allowed to call them without asking each time.

Or add it by its address:

```
https://asof.is/mcp
```

1. In Claude (claude.ai or the desktop app), open Settings, then Connectors, and choose Add custom connector.
2. Name it AsOf and paste the server URL above. There is nothing to sign in to: leave the OAuth fields empty.
3. Open a chat, turn AsOf on in the tools menu, and ask a dated question. Every tool only reads the record, so Claude can be allowed to call them without asking each time.

Claude Code: `claude mcp add --transport http asof https://asof.is/mcp`

ChatGPT, Cursor and any other MCP client: add a remote MCP server (Streamable HTTP) at the address above, with no authentication.

## Questions to ask

### A fact as of a date

- Who was the CEO of OpenAI on 2023-11-18, and what is the source?
- Who ran Nvidia in 2019?
- What was Meta's latest reported revenue as it could have been known on 2024-07-15?

### What changed

- What changed at Anthropic since 1 September 2026?
- Compare Nvidia's record on 2024-01-01 with today: what was added, what ended and what was replaced?
- Who was Microsoft's CEO before Satya Nadella?

### AI models, releases and deals

- What is the latest Claude model, and when was it released?
- Which companies released frontier models last quarter, and how does that compare with the quarter before?

## What an answer carries

- Every value comes with the day it took effect, its sources and a confidence score.
- A replaced value is kept with its end date, so a past day is answered as well as today.
- A role held on an interim or acting basis says so.
- An empty answer says why: the entity is not covered, nothing has been checked yet, or nothing held on that day.
- Each row carries a sentence to cite it by: the value, its as-of date, the claim's address and the primary source.

## Tools

- `entity_state`: Entity state as of a date
- `changes_since`: Changes since a date
- `timeline`: Entity timeline
- `coverage`: Coverage of an entity
- `claim`: Claim by id
- `search`: Search the record
- `trends`: Trends by quarter
- `entity_diff`: Entity diff between two dates
- `models`: AI model families
- `fetch`: Fetch a page as markdown

Every parameter, the limits and API keys: https://asof.is/api-docs.md

## Questions about the connector

### Does the AsOf connector need an account or an API key?

No. During the preview the server answers without a key, within a rate limit per address. An API key lifts that limit for a client that needs more.

### What does the AsOf connector cover?

Tech and AI companies, the people who run them, their products and AI models, and regulators: leadership, ownership, names, financials, headquarters, releases, funding, acquisitions and partnerships. The coverage tool says which sources cover an entity and when each last added or checked something.

### Can the connector change anything?

No. All 10 tools only read the record: nothing is written, and nothing outside the record is reached.

### Does it work outside Claude?

Yes. It is a remote MCP server over Streamable HTTP at https://asof.is/mcp, so ChatGPT, Cursor and other MCP clients can add it. The same record is also a REST API and a set of markdown pages.

### What happens when the record does not hold a fact?

The answer is empty and says why. No claim is not evidence of no fact, and the connector never fills a gap with a guess.