Per SignalsAPI docs, its sources are rechecked every 15 minutes. On each BetterJobs job, the signalsapi entry in sources[] carries first_seen_at and last_seen_at for that source.
SignalsAPI wraps each value in {value, source_board, observed_at, confidence}. BetterJobs records provenance per source instead of per value. Each job has a sources[] array: one entry per provider, with url, first_seen_at, last_seen_at and the fields it contributed. SignalsAPI’s observed_at maps to sources[].last_seen_at.
Cross-source confidence on the whole job is p_real (0 to 1). It comes from corroboration across sources, not from one provider’s confidence. See Provenance and confidence.
Per SignalsAPI docs, some of its 290+ sources are funding databases, news and filings, not job boards. BetterJobs returns jobs. Only signals that resolve to a job opening become, or merge into, a canonical job.
We do not link to SignalsAPI’s docs from this site. Everything you need to use SignalsAPI data through BetterJobs is on this page and in the field dictionary.