Deep fact-check
verify_claimRun the deep check on ONE claim (or up to 10 in claims in parallel) against independent sources and return a verdict with a 1–10 score (or No Public Record when nothing public records the claim), the key finding, warnings and the main sources (about a minute or two).
It costs 10 credits against 1 for assess_claim (depth="low" costs 5; check_usage has the live prices), so the quick check is the default and a plain "check this" is assess_claim. Run the deep check when the user asks for sources, a deep check or a verification, or says yes to one you offered. When they ask for several or all claims, pass up to 10 in claims in one call, or run one per claim, at most 10 calls at once. Checks continue on their own once submitted, so submit every requested claim before calling get_verification to wait on any of them, and report results as they arrive, without asking again. Tell the user it is running. It waits and returns status: completed when the check finishes in time; otherwise status: submitted with a task_id for get_verification, which waits again. A text with several claims returns status: needs_input with the list: call select_claims with the chosen claims' exact text. A completed result replaces any earlier quick verdict on the claim and says how to present it; its suggested_rewrite is an unchecked suggestion.
Tool call template
This tool declares no required parameters. Add optional parameters from the input schema as needed.
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"arguments": {},
"name": "verify_claim"
}
}Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| claim | No | ONE claim, as a statement that makes sense on its own: Lenz sees only this text, not the conversation, so bring in what the conversation says it refers to and change nothing else. A claim a quick check listed goes exactly as listed, so the deep check matches it; otherwise use the user's own words and language, not translated. Leave empty when passing `claims`. | |
| depth | No | How much research to do. "standard" (default) is the full pass. "low" is a shallower one — fewer sources, the same models — for half the credits; it saves only about a fifth of the time, so both take about a minute or two. Pick "low" when the user wants to spend fewer credits. The charge follows the depth you request; the `depth` on the completed result is the depth the verdict was actually produced at (a "low" request may be served from an existing deeper check). | standard |
| claims | No | Up to 10 claims to deep-check in parallel in one call, each a standalone statement or a claim a quick check listed, exactly as listed. Mutually exclusive with `claim`. | |
| language | No | Leave unset: Lenz answers in the language of the text it checks (English when it cannot tell). This field overrides that; the conversation's language and the user's locale are not a request to override it. Set it only when the user asks for the answer in a different language, and keep the text you send in its own words and language: a translated text is a different claim. Supported: en, es, de, fr, it, pt, nl, sv, da, no, fi, bg, sr. |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||