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Export

export writes one row per entry, with the numbers and names that describe the request and none of its content. The output is plain data for jq, a spreadsheet, DuckDB or a script. It has no headers, cookies or bodies in it.

wiretrail checkout.har export --filter "status:>=500" --top 1

{"id":"e000054","offset_ms":13000.0,"duration_ms":221.0,"method":"GET","host":"api.shop.example","norm_path":"/v1/inventory/{id}","status":502,"bytes":56,"content_type":"application/json","resource_type":"api","correlation":"req_52f70893f4"}
{"id":"e000069","offset_ms":25000.0,"duration_ms":243.0,"method":"POST","host":"api.shop.example","norm_path":"/v1/cart/sync","status":503,"bytes":83,"content_type":"application/json","resource_type":"api","correlation":"req_fa6f840121"}
{"id":"e000070","offset_ms":26200.0,"duration_ms":210.0,"method":"POST","host":"api.shop.example","norm_path":"/v1/cart/sync","status":503,"bytes":83,"content_type":"application/json","resource_type":"api","correlation":"req_3ad0e75ca3"}

That command printed six rows, not one, and the block shows the first three. See --top and --json are ignored.

The fields

Field Meaning
id The entry id.
offset_ms When the request started, in milliseconds from the start of the capture.
duration_ms How long it took.
method, host The HTTP method and the host.
norm_path The normalized path, with ids and opaque blobs replaced.
status The status code, 0 for no response.
bytes The response size: the larger of the content size and the body size, and 0 when the capture does not know it.
content_type The response content type, or null.
resource_type api, media, static, analytics, document or other.
correlation The first correlation id from the response headers, or null.

Because it keeps only these fields, export is safe to share as far as these fields are: a host name or a path can still tell a reader something, and content_type and correlation are copied from the response headers as they are. No request header, cookie, body or query value leaves the tool.

NDJSON or CSV

--format chooses. The default is NDJSON, one JSON object per line. --format csv writes a header and one row per entry:

wiretrail checkout.har export --format csv --filter "status:>=500"

id,offset_ms,duration_ms,method,host,norm_path,status,bytes,content_type,resource_type,correlation
e000054,13000,221,GET,api.shop.example,/v1/inventory/{id},502,56,application/json,api,req_52f70893f4
e000069,25000,243,POST,api.shop.example,/v1/cart/sync,503,83,application/json,api,req_fa6f840121
e000070,26200,210,POST,api.shop.example,/v1/cart/sync,503,83,application/json,api,req_3ad0e75ca3
e000072,28700,184,POST,api.shop.example,/v1/cart/sync,503,83,application/json,api,req_67572df288
e000073,33900,234,POST,api.shop.example,/v1/cart/sync,503,83,application/json,api,req_44df04452c
e000076,42100,192,POST,api.shop.example,/v1/cart/sync,500,69,application/json,api,req_1c776b9fff

A field that contains a comma, a quote or a line break is quoted, with quotes doubled. In CSV, offset_ms and duration_ms are whole numbers, and in NDJSON they carry a decimal. The CSV output ends with one empty line.

Put it to work

jq turns the rows into answers. Total time by host:

wiretrail checkout.har export | jq -s 'group_by(.host) | map({host: .[0].host, requests: length, ms: (map(.duration_ms) | add)}) | sort_by(-.ms) | .[0:3]'

[
  {
    "host": "api.shop.example",
    "requests": 63,
    "ms": 11797
  },
  {
    "host": "cdn.shop.example",
    "requests": 15,
    "ms": 4585
  },
  {
    "host": "payments.shop.example",
    "requests": 3,
    "ms": 1333
  }
]

Work with exported data has more.

--top and --json are ignored

export always writes every entry that matches the filter, and it always writes raw rows. Neither --top nor --json changes that:

wiretrail checkout.har export --top 3 | wc -l | tr -d ' '

99

--json prints the same NDJSON rows, with no envelope:

wiretrail checkout.har export --json --filter "status:>=500" | head -1 | jq 'keys'

[
  "bytes",
  "content_type",
  "correlation",
  "duration_ms",
  "host",
  "id",
  "method",
  "norm_path",
  "offset_ms",
  "resource_type",
  "status"
]

To limit the rows, use --filter, or head on the output.

Exit code

export always exits 0.