Verifiable agent answers

This guide shows how an AI agent can give an answer built on Arche data that its reader can check for themselves, without an Arche account.

The problem

When an agent writes "Apple earned 24.78 billion dollars in its second fiscal quarter of 2025", the reader has no way to tell whether the figure came from a filing, from another source, or from the model itself. A link to a filing helps, but it does not show that the agent read that filing on that date.

A replay token closes that gap. It names one query, at one point in time, and the exact result Arche returned for it. Anyone holding the token can ask Arche to run the query again and say whether it still returns the same data.

Get a replay token

The MCP as-of tools, provenance_as_of and financials_get_as_of_snapshot, return a replay_token and a verify_url with every page of statements, beside snapshot_hash:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "provenance_as_of",
    "arguments": {
      "cik": "AAPL",
      "as_of": "2025-06-30",
      "statement_type": "INCOME_STATEMENT"
    }
  }
}

{
  "replay_token": "f111746faeaa0c647c2032f58e8aeaa84287bc44c4484b834c813e5e613d973b",
  "verify_url": "https://arche.fi/verify/f111746faeaa0c647c2032f58e8aeaa84287bc44c4484b834c813e5e613d973b"
}

The token covers the statements on that page and their values. Over HTTP, the same token comes from POST /v1/query/execute; see Deterministic replay.

replay_token is null on the rare page for which a token could not be created. Quote the figures with their accessions as usual in that case.

Quote the token

Have the agent quote three things with each figure it reports:

1. the figure itself
2. the SEC accession number of the filing it came from
3. the verify_url

For example:

Apple's net income for the second quarter of fiscal 2025 was 24,780 million dollars, on revenue of 95,359 million (accession 0000320193-25-000057). Verify: https://arche.fi/verify/f111746f…

An instruction in the agent's system prompt is enough: "When you quote a figure from Arche, give its accession number and the verify_url from the same result."

Verify without a key

The reader opens the verify_url. The page re-runs the query and shows whether it still matches, with each filing it read linked to sec.gov.

The page reads a public route that needs no API key:

curl "https://api.arche.fi/v1/query/verify/REPLAY_TOKEN"

{
  "data": {
    "replay_token": "f111746faeaa0c647c2032f58e8aeaa84287bc44c4484b834c813e5e613d973b",
    "verdict": "MATCHES",
    "matches_original_result": true,
    "query_type": "financials_as_of_page",
    "parameters": {
      "cik": "0000320193",
      "statement_type": "INCOME_STATEMENT",
      "latest_only": true,
      "audit_mode": false,
      "limit": 20,
      "offset": 0
    },
    "as_of_date": "2025-06-30",
    "created_at": "2026-10-13T12:24:46Z",
    "result_hash": "243efd1ffb986914dbd89f432f67764af5dd169b5eec1306e163936360f3f94d",
    "recomputed_result_hash": "243efd1ffb986914dbd89f432f67764af5dd169b5eec1306e163936360f3f94d",
    "accessions": ["0000320193-25-000057"],
    "verified_at": "2026-10-13T12:50:14Z"
  }
}

The response names the query, its hashes and the accession numbers of the filings the answer was read from. It returns no figures: the reader compares the agent's figures with the filings themselves on sec.gov. To read the original figures back, replay the token with an API key at GET /v1/query/replay/{replay_token}.

An unknown token returns 404 with QUERY_REPLAY_NOT_FOUND. The route counts against the snapshot rate limit, by caller address rather than by key.

Reading the verdict

Verify from an agent

An agent can run the same check with the replay_verify MCP tool, which takes replay_token and returns the verdict, the query, its hashes, the accessions and verify_url. Use it when one agent checks another's answer, or to confirm a token before quoting it.

Tokens from code

Code that does not use MCP gets a token from POST /v1/query/execute with the financials_as_of_page query type, which selects statements as the as-of page route does. With the same parameters the MCP tool used, it returns the same token:

curl -X POST "https://api.arche.fi/v1/query/execute" \
  -H "X-Api-Key: $ARCHE_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json" \
  -d '{
    "query_type": "financials_as_of_page",
    "as_of_date": "2025-06-30",
    "include_result": true,
    "parameters": {
      "cik": "0000320193",
      "statement_type": "INCOME_STATEMENT",
      "latest_only": true,
      "audit_mode": false,
      "offset": 0,
      "limit": 20
    }
  }'

data.manifest.replay_token is f111746faeaa0c647c2032f58e8aeaa84287bc44c4484b834c813e5e613d973b, the token in the MCP example above, and data.result holds the statements. A token names its parameters exactly, so leaving one out, even at its default, names a different query and gives a different token. The other query types listed under Deterministic replay return tokens the same way, and the verify route checks any of them.

What a token covers

• One result. A token covers the statements and values of one page from the MCP as-of tools, or of one executed query. Paging with cursor gives each page its own token, so keep the token of each page whose figures you quote.
• Values, not presentation. detail and include_usd change how a statement is shown, not which statements or values it holds, so the token is the same with or without them.
• Its boundary. A token made with a timestamp as_of records the timestamp and re-runs at it; one made with a date re-runs at that date.
• No figures in the check. The verify page and route show the query, the filings and the verdict, so sharing a token shares no figures.