Function resolveAgentCard

apps/sim/lib/a2a/client.ts:159–186

* Resolve (and cache) an agent card. The card is resolved by trying the SDK * default well-known path, the legacy pre-0.3 path, and finally the URL itself * (some agents serve the card at the same URL they serve requests). Resolution * uses a short timeout so a hanging agent fails fast; successfu

(
  agentUrl: string,
  resolvedIP: string,
  signal?: AbortSignal
)

 * cached per URL so subsequent operations skip the discovery round-trips.
 */
async function resolveAgentCard(
  agentUrl: string,
  resolvedIP: string,
  signal?: AbortSignal
): Promise<AgentCard> {
  const cached = getCachedCard(agentUrl)
  if (cached) return cached

  const resolver = new DefaultAgentCardResolver({
    fetchImpl: createPinnedFetch(resolvedIP, { timeout: CARD_RESOLUTION_TIMEOUT_MS, signal }),
  })
  let lastError: unknown
  for (const path of CARD_CANDIDATE_PATHS) {
    try {
      const card = await resolver.resolve(agentUrl, path)
      cacheCard(agentUrl, card)
      return card
    } catch (error) {
      lastError = error
      logger.debug('Agent card resolution failed', {
        agentUrl,
        path,
        error: toError(error).message,
      })
    }
  }
  throw toError(lastError)
}

/**
 * Create an A2A client for an external agent URL. The URL is validated against