Service accounts were never an identity model. Agents make that fatal.

For two decades, non-human callers wore shared, static service accounts — broad, long-lived, and unattributable. That was tolerable when machines were few and supervised. An AI agent is neither: it is provisioned in milliseconds, fans out into sub-agents and tool calls, and reaches the method that moves money thousands of times an hour. A unified fabric requires each agent to be a distinct principal, deriving scoped authority from a provable human — and, critically, an enforcement point that makes that scope binding where the action runs.

The four components of the fabric, mapped to in-process enforcement.

B5 does not replace your IdP or workload-identity issuer — it consumes them and enforces the scoped identity at the exact .NET method the agent invokes.

// TODAY — per-action [Permission] + data-element ADA, enforced in-process
// at the call site, for every principal including AI agents.

[Permission("payments.initiate")]
public async Task<PaymentResult> InitiatePaymentAsync(PaymentRequest req)
{
    // Reached only if the caller carries payments.initiate AND the
    // ADA data-element check passes for req.AccountId.
    return await _ledger.PostAsync(req);
}

// H2 2026 — the agent presents an OBO token (RFC 8693) derived from a
// provable human; B5 binds the delegated, time-bound scope to the call site.

[Permission("payments.initiate", MaxAmount = "delegated")]   // delegated ceiling — H2 2026
public async Task<PaymentResult> InitiatePaymentAsync(PaymentRequest req)
{
    // Reached only if the agent's inherited scope covers this action,
    // the amount is within the delegated ceiling, and risk permits.
    return await _ledger.PostAsync(req);
}

Agentic identity, at financial-grade scope.

B5 is the enforcement substrate — not the whole fabric.