BTrace is a Java diagnostic tool that dynamically inserts tracing into running Java applications without restarting or recompiling them. Java developers and operations teams use it to inspect methods, timings, fields, allocations, and other runtime behavior in production environments. Catalogue add-ons provide instructions for using BTrace.
Borrowing it
Nothing to install: this file belongs to btraceio/btrace. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/btraceio/btrace/develop/CLAUDE.mdgit clone --depth 1 https://github.com/btraceio/btraceWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/btraceio/btrace/claude-md)<a href="https://agentmods.dev/instructions/btraceio/btrace/claude-md"><img src="https://agentmods.dev/badge/instructions/btraceio/btrace/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/btraceio/btrace/claude-md"><img src="https://agentmods.dev/badge/instructions/btraceio/btrace/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00457 | $0.00457 |
| Opus 5.5 | $0.00183 | $0.00183 |
| Sonnet 5.5 | $0.00091 | $0.00091 |
| Haiku 4.5 | $0.00046 | $0.00046 |
Grade A, and why
btrace CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 23d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
Claude Code Guide
Follow the repository-wide rules in AGENTS.md. This file intentionally contains only Claude-specific orientation; AGENTS.md is the canonical operational contract.
Common commands
Use a workspace-local Gradle cache when appropriate, and redirect Gradle output to a log before filtering and reading it (see AGENTS.md).
# Distribution and all unit tests (:btrace-dist:build alone skips most module tests)
GRADLE_USER_HOME=$(pwd)/.gradle-user ./gradlew build
# Module, test class, or formatting check
GRADLE_USER_HOME=$(pwd)/.gradle-user ./gradlew :btrace-agent:test
GRADLE_USER_HOME=$(pwd)/.gradle-user ./gradlew :btrace-agent:test --tests '*InstrStackTest'
GRADLE_USER_HOME=$(pwd)/.gradle-user ./gradlew spotlessCheck
# Integration tests: build the distribution first
GRADLE_USER_HOME=$(pwd)/.gradle-user ./gradlew -Pintegration :integration-tests:test
# Intentional instrumentation-bytecode changes only
GRADLE_USER_HOME=$(pwd)/.gradle-user ./gradlew test -PupdateTestData
Where to look
- Script compiler and verifier:
btrace-compiler - Agent lifecycle and bytecode weaving:
btrace-agent(instrumentation engine lives in itsio.btrace.instrpackage) - Script API, runtime, and protocol:
btrace-core,btrace-runtime - CLI:
btrace-client; packaging:btrace-dist - Golden instrumentation data:
btrace-agent/src/test/resources/instrumentorTestData/
Detailed references
- Documentation index
- Masked JAR architecture — required reading for distribution/class-loading changes
- Instrumentation backends
- Protocol architecture
- Extension development
- Troubleshooting
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 23d ago Changed · +6 tokens per session 36d5ccc4042e
- 2mo ago First seen · 41 lines · 451 tokens per session scan A 783125287985
btrace CLAUDE.md is an instructions file published in the GitHub repository btraceio/btrace (5,997 stars, last pushed yesterday), licensed Apache-2.0. It adds 457 tokens to every session, about $0.0018 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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vibetags com-example-concurrent-SessionCache.instructions.md
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vibetags com-example-config-AsyncTestConfig.instructions.md
Instructions for PIsberg/vibetags, covering copilot instructions for asynctestconfig and immutable type.
vibetags com-example-gmm-platform-FeatureGate.md
Instructions for PIsberg/vibetags, covering amazon kiro steering: featuregate and feature flag gate.