What is prospec-promote-backfill?

A workflow step that turns a reviewed record of existing behavior into formal change documents. A backfill documents behavior that already exists.

Use it to create a proposal, a specification of the differences, and metadata marking the backfill as implemented.

It avoids manually converting an informal backfill draft into the documents needed for later checking and archiving.

How benwu95/prospec configures Claude Code and Codex

Reuse

Borrowing it

Nothing to install: this file belongs to benwu95/prospec. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/benwu95/prospec/main/.agents/skills/prospec-promote-backfill/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/benwu95/prospec

Made for: Claude Code, Codex.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/benwu95/prospec/prospec-promote-backfill/github.svg)](https://agentmods.dev/skills/benwu95/prospec/prospec-promote-backfill)

Your own site

<a href="https://agentmods.dev/skills/benwu95/prospec/prospec-promote-backfill"><img src="https://agentmods.dev/badge/skills/benwu95/prospec/prospec-promote-backfill/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/benwu95/prospec/prospec-promote-backfill"><img src="https://agentmods.dev/badge/skills/benwu95/prospec/prospec-promote-backfill.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 139 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,763 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.

Model	Per session	Once invoked
Fable 5.1	$0.00139	$0.02763
Opus 5.5	$0.00056	$0.01105
Sonnet 5.5	$0.00028	$0.00553
Haiku 4.5	$0.00014	$0.00276

Measured 4d ago against content hash 610e652e7d69, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

prospec-promote-backfill 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 4d 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.

.agents/skills/prospec-promote-backfill/SKILL.md · 143 lines

How it starts

The opening of the file, as written. The whole thing — 143 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Prospec Promote Backfill Skill

Activation

When triggered, briefly describe:

That you'll formalize a reviewed backfill-draft.md into the backfill change scaffold — proposal.md + delta-spec.md + metadata.yaml — so it can graduate through prospec-verify (backfill mode) → prospec-archive
That this is the single, repeatable draft→scaffold step — it replaces ad-hoc hand conversion and is where the scale: backfill marker is set
That backfill is a light scale like quick: it records existing behavior, so there is no plan.md and no tasks.md (nothing to plan, no work to schedule). The scaffold enters the lifecycle directly at status: implemented
That it never writes the trust zone (prospec/specs/features/) — prospec archive (the CLI) stays the sole writer

Language Policy

Write each generated document in the language the Constitution's Language Policy rule assigns to its path — change artifacts and their archived summaries in the project's artifact language, the trust zone (Knowledge base, Feature Specs, index) in English. One skill run may write both. Free text you pass the CLI that lands in a change artifact follows the artifact language too, leaving its paths, commands, enum values and the fixed prefixes the CLI matches untranslated. Keep code, identifiers, technical terms, and git commit messages in English.

CLI Prerequisite (required)

The prospec CLI is a required file for this skill — its deterministic steps call prospec commands. Probe BEFORE any other step; there is no manual fallback.

Run prospec --version (Bash).
Command not found / not executable → STOP. Ask the user to install the prospec standalone executable — the one-click installer script from the project README (macOS/Linux install.sh, Windows install.ps1) or a release binary from GitHub Releases; prospec is NOT published to npm. Then re-run this skill.
Version older than 2.10.0 → STOP. Report the installed vs required version and ask the user to upgrade, then re-run this skill.

Read the full file on GitHub · 143 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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.

4d ago Changed 610e652e7d69
9d ago Changed 5b9c0617da03
13d ago Changed dc3180f95582
13d ago Changed 249394eec10d
20d ago Changed 8bd221e39cde
23d ago Changed d888356e03b2
28d ago Changed c8692663415e
1mo ago Changed · +2 lines cd533124f540
1mo ago Changed 9f74be1ff006
1mo ago First seen · 141 lines · 139 tokens per session scan A ab788233116e

Subscribe to this mod's changes

prospec-promote-backfill is a skill published in the GitHub repository benwu95/prospec (6 stars, last pushed yesterday), licensed MIT. It adds 139 tokens to every session and 2,763 once invoked, about $0.0006 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 2026-08-31.

agentic-coding ai-coding-assistant ai-knowledge progressive-disclosure sdd spec-driven-development

prospec-promote-backfill next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
prospec-promote-backfillbenwu95/prospec	Skill	6	yesterday	MIT	A	139	Claude Code, Codex
ospec-goalclawplays/ospec	Skill	390	2mo ago	MIT	A	29	Codex
ospecclawplays/ospec	Skill	390	2mo ago	MIT	A	26	Claude Code, Codex
ospec-changeclawplays/ospec	Skill	390	2mo ago	MIT	A	18	Codex
review-spdzhu1090093659/spec_driven_develop	Skill	993	3mo ago	MIT	A	72	Claude Code
deep-discusszhu1090093659/spec_driven_develop	Skill	993	3mo ago	MIT	A	181	Claude Code
spec-driven-developzhu1090093659/spec_driven_develop	Skill	993	3mo ago	MIT	A	148	Claude Code

prospec: Skill for Claude Code