bf-replay

bf-replay is a skill for Claude Code from chan4lk/specclaw. It costs 799 tokens per session (12,354 once invoked), scanned A, original, MIT.

A regression-checking skill that replays recorded examples from a legacy application against the rebuilt application and reports whether each result matches, differs, or errors.

In plain words
What is it for?
Use it to replay examples for one backlog item, module, change, or the entire recorded test set.
Why use it?
It helps detect behaviour changes when replacing an older system. It separates checking legacy behaviour from checking whether a new change meets its own specification.

Skill for Claude Code

Written for Claude Code: $CLAUDE_PLUGIN_ROOT variable.

Runs only inside its plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else. Install the plugin, not this.

Part of the specclaw plugin — 32 skills, 21 agents shipped together

Good fit Use it to replay examples for one backlog item, module, change, or the entire recorded test set.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.

Claude Code
/plugin marketplace add chan4lk/specclaw
Claude Code
/plugin install specclaw

Made for: Claude Code.

Or install specclaw, the plugin that ships this one along with the rest of its 32 skills, 21 agents.

Wrote 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.

agentmods badge for bf-replay

README.md
[![agentmods](https://agentmods.dev/badge/skills/chan4lk/specclaw/bf-replay/github.svg)](https://agentmods.dev/skills/chan4lk/specclaw/bf-replay)
Your own site
<a href="https://agentmods.dev/skills/chan4lk/specclaw/bf-replay"><img src="https://agentmods.dev/badge/skills/chan4lk/specclaw/bf-replay/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.

agentmods 80×15 button for bf-replay

Your own site · 80×15
<a href="https://agentmods.dev/skills/chan4lk/specclaw/bf-replay"><img src="https://agentmods.dev/badge/skills/chan4lk/specclaw/bf-replay.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 799 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 12,354 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00799 $0.12354
Opus 5 $0.00400 $0.06177
Sonnet 5 $0.00160 $0.02471
Haiku 4.5 $0.00080 $0.01235

Measured 5d ago against content hash 4e82f1256b60, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

bf-replay 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 5d 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.

plugins/specclaw/skills/bf-replay/SKILL.md · 299 lines

How it starts

The opening of the file, as written. The whole thing — 299 lines — stays where its author put it; the contents beside it link to each section on GitHub.

specclaw bf-replay

First, run specclaw-ensure-init .specclaw — idempotently creates .specclaw/ if it doesn't exist (silent if already initialized).

Compares the new app's actual behaviour against .specclaw/baseline/'s captured golden-master fixtures. This is not /specclaw:verify — verify checks a change against its own spec/tasks; replay checks the rebuild against the legacy app's own recorded behaviour. Neither command modifies the other; do not merge this flow into verify.

Invocation:

/specclaw:bf-replay <change-name>                    # fixtures behind this change's cited BL item; retains evidence
/specclaw:bf-replay --item BL-###                    # fixtures behind ONE backlog item; no change directory needed
/specclaw:bf-replay --module MOD-###                 # every fixture tagged with that module; retains evidence
/specclaw:bf-replay --all                            # full regression: every fixture in the manifest; retains evidence
/specclaw:bf-replay <change-name> --keep              # accepted for compatibility — identical to the default
/specclaw:bf-replay <change-name> --discard           # opt this one run out of evidence retention (never for an acceptance run)
/specclaw:bf-replay <change-name> --prune-evidence <n> # keep only the newest n evidence runs for this change; no new replay run

Four selection scopes, smallest to largest: --item BL-###<change-name>--module MOD-###--all. --item is the single-item acceptance gate — accept one backlog item's behaviour on its own, before any change exists for it and without inventing one. --module is the module-at-a-time gate: it replays every fixture the manifest tags with that module, so a large legacy system can be migrated and behaviourally signed off one flow at a time instead of all-or-one-change. All four are selection only — verdict logic, the four-step verdict order, PROVISIONAL semantics, ST-### taint mechanics, and every exit code are identical across every one of them.

The four scopes are mutually exclusive. A positional <change-name> combines with no scope flag, and the flags combine with nothing. Retention qualifiers (--keep, --discard, --prune-evidence <n>) qualify a run rather than selecting one, and combine with any scope.

Never decide the scope by reading the invocation yourself — resolve it mechanically first:

target="$(specclaw-bf-replay parse-target <the user's flags and arguments, verbatim>)"

It prints the one canonical target token (<change-name> | BL-### | MOD-### | --all) or fails loudly naming the conflict. If it exits non-zero, surface its stderr verbatim and stop. Pass $target as the target argument to resolve, render, and finalize — every subcommand accepts all four forms in the same argument position, so no separate flag is threaded through five call sites.

Read the full file on GitHub · 299 lines

Changes

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.

  1. 5d ago First seen · 299 lines · 0 tokens per session scan A 4e82f1256b60

Subscribe to this mod's changes

bf-replay is a skill published in the GitHub repository chan4lk/specclaw (12 stars, last pushed 6d ago), licensed MIT. It adds 799 tokens to every session and 12,354 once invoked, about $0.0040 per session on Opus 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 2026-09-05.

Related

Other skills, from other repositories

run-preflight

A release pre-check workflow that builds the mini-app, runs automated checks, explains errors, and lists review items that require a person to test the app on a real device. A preflight check is a final inspection before submission.

TOKTOKHAN-DEV/agent-company · 3 tokens

ai-dev-team

The AI Dev Team contract — how work is run in any project using this framework: proportional process, TDD, behaviour-only tickets, which process skills exist and when to reach for them, and the git conventions. Load this at the START of any development task, when picking an agent or handing off between roles, and…

olehsvyrydov/AI-development-team · 84 tokens

product-verification

Drive the running product and verify it works end-to-end. Use this skill after a deploy, before a release, or when the user says "verify", "smoke test", "does it work", "test the flow", "check staging", "end-to-end test", or "drive the product". Also use when the user wants to verify a specific user journey (signup…

rbah31/claude-code-workflow · 112 tokens

smoke-test

Post-sprint validation. Verifies the application works as expected after a sprint completes. Use after any sprint or deployment, or when the user says "smoke test", "verify it works", "test the app", "does it still work", "regression check", "post-deploy check", or "sanity check". Invoked by SP-QA during post-sprint…

rbah31/claude-code-workflow · 83 tokens

implement

Use in the Implement phase whenever writing or editing production Java code, or fixing a bug, in a Spring/Spring Boot project. Enforces test-first (red-green-refactor), executes the approved plan step by step, and honors the project's path-scoped tech-stack rules and the task's enforcement set. Preloaded into…

taipt1504/claudehut · 73 tokens

systematic-debugging

4-phase root cause debugging: understand bugs before fixing.

NousResearch/hermes-agent · 16 tokens