What a compound can become, and through what (inferred, a hypothesis)
reachAnswers a route question: "can X become Y in the body" (give from_id and to_id) and "what can X become" (give only from_id). Both ids are compound node ids from search_nodes, so a question that names two compounds needs one search_nodes call for each first. It searches the reactions two public databases (Rhea, Human-GEM) record, up to depth steps (1 to 3, default 3), and returns the routes with the reactions and enzymes along each. Every route is assertion_class 'inferred': a hypothesis drawn from reference databases, never a measured or reported effect. Present it as known biochemical connectivity, never as an effect, a recommendation, or a claim that the body actually does this. For measured effects, use find_evidence. Common cofactors and currency species (water, ATP, protons and the like) are not used as intermediate steps, so a route never reads 'reaches everything through ATP'. A currency species given as from_id or to_id returns reachable: null with a coverage note, not a checked 0 routes. With from_id alone it lists up to limit routes (default 10, offset pages the rest); a page too large for one result is cut to fit, and truncated with next_offset says how to get the rest. When no route is found, the coverage field says which of three cases it is: reachability has not been built for this scope yet, so nothing was checked; it was checked and no route exists through the reactions loaded, which does not mean the body cannot make it; or the compound is a currency species and was never searched. The answer is in that one result; another tool does not check it again.
Tool call template
Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"arguments": {
"from_id": "<from_id>"
},
"name": "reach"
}
}Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| depth | No | Longest route to consider, in reaction steps (1 to 3). | |
| limit | No | Routes to return when to_id is omitted (1 to 50). | |
| to_id | No | A target compound: a compound node id from search_nodes. Omit to list everything from_id reaches. | |
| offset | No | Routes to skip when to_id is omitted, to page past limit. | |
| from_id | Yes | The compound to start from: a compound node id from search_nodes. |