Traces¶
Traces is the core Python SDK client for conversation observability, audio analysis, speech-to-text transcription auditing, and BigQuery log reprocessing.
It provides programmatic access to: - Retrieving full conversation turn details, event timestamps, and tool calls. - Discovering user and agent turn audio recordings stored in GCS buckets. - Transcribing user speech turns with Gemini multimodal Flash / Flash-Lite models. - Evaluating Word Error Rate (WER) metrics against CES reference transcripts. - Filtering turns for non-English / foreign utterances. - Reprocessing transcription updates into cloned BigQuery conversation export tables in parallel.
Quick Example¶
1. Transcribe User Audio & Calculate WER¶
from cxas_scrapi.core.traces import Traces
app_name = "projects/my-project/locations/us/apps/my-app"
traces = Traces(app_name=app_name)
# 1. Discover user audio recordings from GCS for a conversation
user_audios = traces.get_user_audio_uris(conversation_id="conv-12345")
for item in user_audios:
print(f"Turn {item['turn_index']}: {item['audio_uri']}")
# 2. Transcribe turns using Gemini Flash and compute WER metrics
results = traces.transcribe_user_turns(
conversation_id="conv-12345",
model="gemini-3.5-flash",
only_non_english=False,
max_workers=8,
)
for res in results:
wer = res["wer_metrics"]
print(
f"Turn {res['turn_index']}: "
f"WER={wer['wer']:.1%} "
f"(Subs={wer['substitutions']}, Dels={wer['deletions']}, Ins={wer['insertions']})"
)
print(f" CES Ref: {res['reference_transcript']}")
print(f" Gemini Hyp: {res['gemini_transcript']}")
2. Reprocess Conversations into BigQuery Updates Table¶
# Reprocess user turn messages into a shared BigQuery updates table
reprocess_summary = traces.reprocess_transcriptions(
conversation_id="conv-12345",
model="gemini-3.5-flash",
only_non_english=True, # Only reprocess non-English/accented turns
output_table="my_dataset.reprocessed_transcripts",
max_workers=16,
)
print(f"Output Table: {reprocess_summary['output_table']}")
print(f"Reprocessed Turns: {reprocess_summary['total_turns_reprocessed']}")
print(f"Overall WER: {reprocess_summary['overall_wer']:.1%}")
3. Direct Word Error Rate (WER) Utility Usage¶
from cxas_scrapi.utils.tracing.audio_transcription import (
AudioTranscriber,
calculate_wer,
contains_non_english,
normalize_text,
)
# Calculate WER between reference and hypothesis
ref = "I would like to check my account balance please"
hyp = "I'd like to check my account balance please"
metrics = calculate_wer(ref, hyp, normalize=True)
print(f"WER: {metrics['wer']:.2%}")
print(f"Substitutions: {metrics['substitutions']}, Hits: {metrics['hits']}")
# Detect non-English characters
is_foreign = contains_non_english("Hola, ¿cómo estás?")
print(f"Contains non-English: {is_foreign}")
Reference¶
Traces ¶
Traces(app_name, app_dir='.', env_file=None, environment=None, trace_config_path=None, creds_path=None, creds_dict=None, creds=None, scope=None, **kwargs)
Bases: Common
Orchestrates listing, fetching, enriching and analyzing conversations.
Construction is cheap: it loads the trace config and (optionally) the pulled-app config, and instantiates a ConversationHistory client. The heavier clients (Cloud Logging, Gemini, GCS) are lazily created on first use so a cxas trace list call does not require any of those packages to be reachable.
Source code in src/cxas_scrapi/core/traces.py
get_user_audio_uris ¶
Returns a mapping of {turn_index: gcs_uri} for user turn recordings.
Discovers audio files for the given conversation and extracts the turn number from filenames matching user-turn-<N>.wav.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
conversation_id | str | The conversation ID. | required |
Returns:
| Type | Description |
|---|---|
dict[int, str] | Dict mapping integer turn_index to GCS URI. |
Source code in src/cxas_scrapi/core/traces.py
transcribe_user_turns ¶
transcribe_user_turns(conversation_id, model_name=DEFAULT_TRANSCRIPTION_MODEL, only_non_english=False, prompt=None, max_workers=8)
Transcribes user audio recordings for a trace and evaluates WER.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
conversation_id | str | Conversation ID of the trace. | required |
model_name | str | Gemini model name for transcription (default: gemini-2.5-flash). | DEFAULT_TRANSCRIPTION_MODEL |
only_non_english | bool | If True, only reprocesses turns that contain non-English characters. | False |
prompt | str | None | Optional custom prompt instruction for transcription. | None |
max_workers | int | Maximum worker threads for parallel transcription. | 8 |
Returns:
| Type | Description |
|---|---|
list[dict[str, Any]] | List of dictionaries for each user turn containing transcription |
list[dict[str, Any]] | and WER metrics. |
Source code in src/cxas_scrapi/core/traces.py
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reprocess_transcriptions ¶
reprocess_transcriptions(conversation_id=None, output_table=None, source_table=None, bq_dataset=None, bq_project=None, model_name=DEFAULT_TRANSCRIPTION_MODEL, only_non_english=False, dry_run=False, limit=None, prompt=None, max_workers=8)
Reprocesses user speech transcriptions from GCS audio, computes WER, and appends updated turn records to a BigQuery destination table.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
conversation_id | str | None | Optional specific conversation ID. If omitted, reprocesses conversations found in the BigQuery source table. | None |
output_table | str | None | Target BigQuery table name or qualified reference (e.g. | None |
source_table | str | None | Source BigQuery table name containing conversations. Defaults to the app's CES BigQuery export table. | None |
bq_dataset | str | None | Optional BigQuery dataset override. | None |
bq_project | str | None | Optional BigQuery project override. | None |
model_name | str | Gemini Flash / Flash-Lite model name (default: gemini-2.5-flash). | DEFAULT_TRANSCRIPTION_MODEL |
only_non_english | bool | If True, only reprocesses turns that contain non-English characters. | False |
dry_run | bool | If True, calculates transcriptions and WER without mutating BigQuery. | False |
limit | int | None | Maximum number of conversations to process. | None |
prompt | str | None | Optional transcription prompt override. | None |
max_workers | int | Maximum worker threads for concurrent processing. | 8 |
Returns:
| Type | Description |
|---|---|
dict[str, Any] | Summary dictionary with aggregate metrics and per-turn details. |
Source code in src/cxas_scrapi/core/traces.py
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AudioTranscriber ¶
AudioTranscriber(project_id, credentials=None, model_name=DEFAULT_TRANSCRIPTION_MODEL, location='global', **kwargs)
Handles audio transcription using Gemini Flash / Flash-Lite models and
computes transcription accuracy metrics.
Initializes the AudioTranscriber.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
project_id | str | Google Cloud project ID. | required |
credentials | Any | Optional credentials object. | None |
model_name | str | Gemini model name (default: gemini-2.5-flash). | DEFAULT_TRANSCRIPTION_MODEL |
location | str | Vertex AI location. | 'global' |
**kwargs | Any | Additional keyword arguments. | {} |
Source code in src/cxas_scrapi/utils/tracing/audio_transcription.py
calculate_wer ¶
Calculates Word Error Rate (WER) between reference and hypothesis text.
Computes standard word-level Levenshtein edit distance
WER = (Substitutions + Deletions + Insertions) / Reference_Word_Count
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
reference | str | Ground truth / baseline transcript (e.g. CES transcription). | required |
hypothesis | str | Predicted / generated transcript (e.g. Gemini transcription). | required |
normalize | bool | Whether to normalize case, punctuation, and whitespace before computing WER. Defaults to True. | True |
Returns:
| Type | Description |
|---|---|
dict[str, Any] | Dictionary containing: - wer: float (rounded to 4 decimal places) - substitutions: int - deletions: int - insertions: int - hits: int (matching words) - reference_words: int - hypothesis_words: int - reference_tokens: list[str] - hypothesis_tokens: list[str] |
Source code in src/cxas_scrapi/utils/tracing/audio_transcription.py
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normalize_text ¶
Normalizes text and tokenizes it into a list of word tokens.
Applies Unicode NFKC normalization, lowercase folding, and splits into alphanumeric/word tokens while preserving international/unicode characters and apostrophes within words (e.g. "don't", "it's").
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
text | str | The raw input string. | required |
Returns:
| Type | Description |
|---|---|
list[str] | List of normalized word tokens. |
Source code in src/cxas_scrapi/utils/tracing/audio_transcription.py
contains_non_english ¶
Checks if text contains non-English / non-ASCII characters.
Detects characters with code point > 127 (such as accented characters, emojis, or non-Latin alphabets) which indicate non-English speech or transcription anomalies.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
text | str | The text to inspect. | required |
Returns:
| Type | Description |
|---|---|
bool | True if any character is non-ASCII (code point > 127). |