sandbox-proxy

Logs

The proxy writes three files to PROXY_DATA_DIR (default /proxy-data). They ship with the Harbor job artifact. Headers, including Authorization, are never logged.

File	Contents
proxy_usage.json	Cumulative cost snapshot for the run, rewritten after each successful call and at shutdown.
proxy_inferences.jsonl	One stats line per request.
proxy_inference_payloads.jsonl	One content line per request, joined to the stats line by seq.

seq is <boot id>-<n>. Each proxy process has its own boot id, so values never collide across processes or restarts.

Stats line fields worth knowing

• status_code is what upstream returned; returned_status_code is present only when the agent got something else, for example a 429 once a response pushed the run over budget, or a 502 for an unusable upstream body.
• error is set for every failure, including errors OpenRouter reports inside a 200 body (top-level error, or choices[].error next to partial output). Those calls usually carry no usage, so their cost is 0.
• provider is the model vendor taken from the slug (deepseek for deepseek/...). serving_provider is who actually served the call, when upstream says so.
• cached_tokens, reasoning_tokens and finish_reason are null when the provider does not report them.

Payload line

• request is the body sent upstream, after policy strips fields and injects provider preferences, usage and the seed. If the request was rejected before that rewrite, it is the agent's payload.
• received_request is the agent's payload as received, present whenever request is the rewritten body. Fields policy dropped (e.g. logprobs) survive only here.
• response is the full upstream body (null if the proxy rejected the request). Embedding vectors are replaced by their size, and a non-JSON body is kept as {"raw_text": ...}.
• messages (per message) and tools (as one blob) are stored as content hashes. A line defines a hash in blobs only the first time this process writes it, and lines are written in completion order, not seq order. Readers must collect every blobs map in the file before resolving hashes.
• Content logging stops once the file reaches MAX_PAYLOAD_LOG_BYTES (default 64 MiB). Later lines keep seq, status and error, and carry truncated: true with no request or response.