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Plannotator

annotate agent plans, diffs, and HTML

Details

External ID
48495970
Source
HN
Company
—
Product
Plannotator
Website domain
github.com
Launched
June 11, 2026
Cohort
—
Upvotes
5
Upvotes percentile
0.12568306010928962
Tags
—
Fetched at
Sept. 7, 2026, 9:26 p.m.
Updated at
Sept. 7, 2026, 9:26 p.m.

Description

I started this in January as a hook for Claude Code's plan mode: when it finished planning, instead of approving a wall of text in the terminal, the plan opens in your browser and you could mark it up like a document. Your annotations go back into the agent session.It grew from there. There's now PR-style code review (git, jj, p4, GitHub/GitLab PRs) and annotation for markdown, URLs, and folders. Agents produce a lot of HTML now, so Plannotator renders those artifacts and lets you annotate them too. Nine harnesses are supported: Claude Code, Codex, Copilot CLI, Gemini, OpenCode, Kiro, Droid, Amp, and Pi. Over 100 contributors.Nothing leaves your machine unless you share... which is E2E encrypted: eg. the plan is encrypted in the browser, the server stores ciphertext, and the key lives in the URL fragment.As agents get better, the bottleneck shifts to review before and after agents work (obvious to us all now).Open source, MIT or Apache-2.

Enrichment

Theme
Claude integrations and coding agents
Vertical
Horizontal
Function
Observability & eval
Audience
Developer
AI stance
AI feature
Project type
Commercial product
Normalized one-liner
annotation tool for agent plans and diffs
Manually corrected
False

Could you build this?

Yes It provides a local web server displaying agent plan text and diffs with standard browser annotation tools, sending user comments back via CLI or MCP hooks.

Discussion

2 comments analyzed.

Competitors

Other products that read as similar to this one — 191 launches clear the similarity bar, closest 8 shown.

Attention rank: #162 of 192 (itself plus its competitors, highest first — normalized so YC and Product Hunt are compared fairly).

Launched 213 days after the earliest competitor.

Other launches for this product

Same idea, different domain

Nobody's really built a observability & eval tool for Media & entertainment yet.