OpenCode vs Pretty Fish

“The primitive is clean: a local client/server AI coding agent where the server handles tool execution and model I/O against SQLite, and the frontend is swappable — TUI today, IDE extension tomorrow. The DX bet is that developers would rather manage their own API keys than pay a subscription tax, and that bet is correct for anyone who has ever watched Claude Code quietly bill $40 in an afternoon. The moment of truth is `opencode` in a terminal, Tab to switch between Build and Plan agents, and LSP-backed edits that actually know your project structure — it survives that test, and the Go binary means it starts fast and stays fast. The Build/Plan split is the specific technical decision that earned the ship: it's the right primitive for separating 'I want to understand this codebase' from 'I want to change it,' and it would have taken real thought to get that separation right without making it clunky.”

“The official Mermaid live editor is clunky and slow. Pretty Fish loads instantly, works offline, and the multi-page workspace means I can manage all my architecture diagrams in one place. Bookmarking this immediately as my default Mermaid editor.”

“Category is local AI coding agents; direct competitors are Claude Code, Aider, and Continue.dev — and OpenCode beats all three on the specific axis of 'zero code egress with model flexibility,' which is a real constraint, not a vibe. The scenario where it breaks is a developer on a Windows machine with no terminal fluency who needs inline diffs in VS Code — the TUI-first model will lose that user to a Copilot extension every time, and the IDE extension is listed as a frontend option but not a shipped reality as of review. The thing that kills it in 12 months is Anthropic shipping Claude Code as a self-hostable binary, which removes the privacy moat for the Anthropic-key users who are currently the majority of the audience — but the 75-model support and open-source composability give it a real survival path even then.”

“It's a genuinely nice editor but it's solving a niche problem — most devs who need Mermaid diagrams already use VS Code extensions or embed them in Notion. And with no backend, there's no collaboration or sharing story, which limits its use in team workflows.”

“The buyer here is the engineering lead at a Series B fintech or healthcare startup who has been told by legal that production code cannot touch an external API — that is a real budget line and a real buyer, and OpenCode is the first open-source tool positioned cleanly for it. There is no direct revenue, which is fine: the moat is not the business model but the community flywheel — 143K GitHub stars in under a year means contributors and integrations compound in ways that a VC-funded closed competitor cannot easily replicate. The existential risk is not commoditization but abandonment — Anomaly Innovations needs to show a credible sustainability story, because open-source AI tooling graveyards are full of well-starred repos whose maintainers burned out six months after the HN launch.”

“The thesis is falsifiable: by 2028, AI coding agents will be infrastructure-level commodities, and the teams that win will be those who own the execution layer locally — because model costs drop to noise but data sovereignty regulations tighten, especially in EU, healthcare, and defense. OpenCode is early on the local-execution trend line, not on-time, which is where you want to be; the second-order effect is that when enterprises adopt it, they start treating the AI model as a pluggable dependency rather than a vendor relationship, which structurally shifts negotiating power away from Anthropic and OpenAI and toward whoever controls the agent runtime. The dependency that has to hold: model API standardization continues rather than fracturing into incompatible proprietary protocols — if OpenAI and Anthropic diverge sharply on function-calling schemas, the 75-model promise gets expensive to maintain and the abstraction layer becomes the product's biggest liability.”

“As AI tools increasingly output Mermaid syntax to explain architectures and flows, the need for a great rendering environment grows. Pretty Fish positions itself at the intersection of AI-generated diagrams and human editing — that's a well-timed niche.”

“Five beautiful themes and clean SVG exports mean I can finally use Mermaid diagrams in client-facing presentations without them looking like developer scratch notes. This is the Mermaid editor I've always wanted and the zero-friction setup seals it.”