bedrock-lens 0.1.2

Real-time token usage and cost monitoring for AWS Bedrock

bedrock-lens

Real-time token usage and cost monitoring for AWS Bedrock — because Cost Explorer won't tell you until tomorrow.

Model	Calls	Input Tokens	Output Tokens	Total Tokens	Est. Cost
Claude Opus 4	2	12,540	3,812	16,352	$0.4746
Claude Sonnet 4	14	48,300	11,220	59,520	$0.3132
Claude Haiku 4	38	63,807	9,441	73,248	$0.0888
Llama 3.1 70B	5	4,200	1,830	6,030	$0.0060
TOTAL	59	128,847	26,303	155,150	$0.8826

The problem

When running Bedrock agents, you're flying blind. AWS Cost Explorer has a 24–48 hour lag. CloudWatch has live data, but getting to it requires knowing the log group name, converting dates to epoch milliseconds, parsing deeply nested JSON, and doing the cost math yourself.

There's no bedrock usage command. This is that command.

Install

pip install bedrock-lens

Or with uv:

uv tool install bedrock-lens

Usage

bedrock-lens                        # today's usage (default)
bedrock-lens --yesterday
bedrock-lens --week
bedrock-lens --since 2h             # last 2 hours
bedrock-lens --since 30m            # last 30 minutes
bedrock-lens --since 1d             # last 1 day
bedrock-lens --live                 # tail mode, refreshes every 5s
bedrock-lens --since 1h --live      # live tail for the last hour
bedrock-lens --live --threshold 2   # alert when spend crosses $2
bedrock-lens --setup                # one-time setup wizard

# different profile / region
bedrock-lens --profile my-profile --region us-west-2

First-time setup

Bedrock doesn't log invocations by default. Run the setup wizard once per AWS account:

bedrock-lens --setup

This creates the CloudWatch log group, an IAM role for Bedrock to write to it, and enables model invocation logging. Takes about 10 seconds. After that, every Bedrock call shows up within ~30 seconds.

If you don't have IAM permissions to create roles, the wizard prints the exact policies and CLI command to hand off to your admin.

How it works

Bedrock writes a JSON record to /aws/bedrock/model-invocations in CloudWatch for every model call. Each record contains the model ID, input token count, and output token count. bedrock-lens reads those records, applies per-model pricing, and renders the table.

Live mode (--live) polls every 5 seconds with a 90-second overlap window to handle CloudWatch's ingestion delay, deduplicating events by ID so nothing gets double-counted.

Supported models

Claude (Haiku, Sonnet, Opus — v3 through v4), Amazon Titan, Meta Llama 3 / 3.1 / 3.2, Mistral, Mixtral, Cohere Command R / R+, AI21 Jamba.

Pricing is per the AWS on-demand rates for us-east-1. Unknown models show N/A for cost but still display token counts.

Requirements

• Python 3.9+
• AWS credentials with logs:FilterLogEvents on /aws/bedrock/model-invocations
• Bedrock model invocation logging enabled (run --setup if not)