branch.preview

A read-only preview of merging one branch into another. A branch is a separate line of project changes, and the preview reports files or values both branches changed differently since they split.

In plain words
What is it for?
Use it to check whether a branch promotion is clean, review conflicts under strict or source-wins handling, and inspect differences in key-value data, JSON, or vectors.
Why use it?
It shows likely conflicts and the result of a selected conflict strategy before either branch is changed.

Command

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/stratalab/strata-core/branch.preview
Clone the repo
git clone --depth 1 https://github.com/stratalab/strata-core
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 217 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00000 $0.00217
Opus 5 $0.00000 $0.00109
Sonnet 5 $0.00000 $0.00043
Haiku 4.5 $0.00000 $0.00022

Measured 2d ago against content hash c67c195bb6ec, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

branch.preview 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 2d 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.

crates/executor/idl/v1/prose/commands/branch.preview.md · 19 lines

What it actually says

Previews promoting the source branch into the target branch: it derives the branch point from the recorded fork lineage, runs a three-way comparison, and reports the conflicts a promotion would hit — entries both branches changed differently since the branch point. Preview is read-only: it mutates neither branch.

Each conflict reports what the selected strategy would do — strict refuses (refused), source_wins overwrites the target with the source value. A preview with no conflicts is clean and a promotion under strict would apply. Preview covers the capabilities a promotion applies — key-value, JSON, and vectors; events and graphs are diff-only and never appear as promotion conflicts. Branches with no shared fork lineage are rejected with invalid_argument.engine.branch_point.

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. 2d ago First seen · 19 lines · 0 tokens per session scan A c67c195bb6ec

Subscribe to this mod's changes

branch.preview is a command published in the GitHub repository stratalab/strata-core (2 stars, last pushed 2d ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 217 tokens. 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.