Why not just a trace viewer

Trace tools answer "what did my agent do?" AgentLedger answers "what did my agent cost, and is it allowed to keep going?" Those are different questions, and only one of them has a bill attached.

The difference that matters

The unit of accounting. Trace viewers key on the request, so cost is something you reconstruct from a span tree. AgentLedger keys on the agent, so "what does my research agent cost me per month" is the primary query rather than a derived one.

And the enforcement. A trace viewer reports that you spent $400. None of them stop the $401st call. That is the whole product.

Honest comparison

Prices are list prices as published on each vendor's pricing page, checked 2026-09-13. Verify before you buy — they change.

• LangSmith — per seat, $39/seat/month plus per-trace overage. Traces, evals, prompt playground. No budget enforcement.
• Helicone — free up to 10k requests/month, $79/month Pro when paid annually. A gateway with observability; request-keyed. No enforced caps.
• Langfuse / OpenLIT / Arize — open-source core plus paid trace volume. Observability first, no enforcement.
• Braintrust — $249/month entry. Eval and experiment platform, aimed at teams with an eval budget.
• Datadog LLM Observability — priced into an observability contract (the LLM SKU is a low-hundreds-per-month add-on). Buyer is ops, not the person running the agent.

What we are not

We are not a trace viewer, an eval platform, or a prompt playground, and we are not trying to be. If you need deep trace inspection, pair one of the above with us: they show you the call, we keep the total from becoming a surprise. AgentLedger is $19/month per workspace, flat, regardless of seat count.

AgentLedger — not affiliated with agentledger.co or other same-named projects · start in 5 minutes