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Helicone logs vs audit evidence

Helicone sits between your app and the model provider and logs every request: cost, latency, prompts, responses. For an auditor those logs have two gaps. They live in an account your team can edit. And they only see model calls: the tool calls and decisions your agent makes between two requests never reach the proxy.

You can keep Helicone exactly as it is and add an evidence trail next to it.

1. Add OpenTelemetry to the agent

Helicone is a proxy, not an OpenTelemetry backend, so the evidence trail comes from the app itself. Add an OpenTelemetry instrumentation that emits the GenAI conventions, for example OpenLLMetry (traceloop-sdk), OpenLIT, or the Vercel AI SDK's experimental_telemetry. Point OTEL_EXPORTER_OTLP_ENDPOINT at a local Collector. Your model calls keep going through Helicone's base URL as before, and the spans record them together with the tool calls around them.

2. Write the spans to a file

receivers:
  otlp:
    protocols:
      http: { endpoint: 0.0.0.0:4318 }
exporters:
  file/evidence:
    path: /var/otel/traces.json
    format: json
service:
  pipelines:
    traces:
      receivers: [otlp]
      exporters: [file/evidence]

(otelcol-contrib build, which includes the file exporter.)

3. Merge, paste, attest

jq -cs '{resourceSpans: map(.resourceSpans[])}' /var/otel/traces.json > run.otlp.json

Paste the file into the verifier. Spans with gen_ai.request.model and gen_ai.usage.* become model calls, and execute_tool spans become tool calls. Each trace becomes one hash-chained run with a third-party countersignature and an RFC 3161 timestamp. Helicone stays your cost dashboard, and this file is your evidence. See the sample report.

Limits

It attests what your instrumentation recorded, starting from when you add it. For prompt and response bodies and for policy checks before a tool runs, use the SDK adapters (Start in 1 minute). Also see Vetro vs Helicone.

See a sample ledger verified in one click, check your own logs free or get the countersigned EU AI Act report.

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