The others observe. Runback re-executes and proves.
Every other tool in this space is read-only — it shows you a trace and stops. Runback is the only platform that re-runs a decision deterministically, seals a tamper-evident record, and gates the next change against policy.
Capability
Runback
Observability toolsLangSmith · Langfuse · Arize · Braintrust
See what the agent did
✓
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Reproduce a real incident bit-for-bit
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Continue a counterfactual past the first divergence
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Bisect the model/prompt change that caused a regression
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Simulate a policy against history, then enforce it live
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Regression tests auto-mined from incidents
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Replay fidelity compounds with every captured run
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Tamper-evident, signed system of record
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Async-scoped env interception (AsyncLocalStorage)
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Salience projection for nondeterministic inputs
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Merkle-rooted ledger with domain-separated nodes
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Runs in your perimeter · self-hostable
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mostly SaaS
Read-only observability is a crowded category. Re-execution and proof is a category of one — and every claim above runs green in public CI ↗.
See the difference in 4 minutes.
Open a real failing run — no signup required.