Nicheloom

Market intelligence for builders — see what's gaining traction before it's crowded.

2 weeks of coding, 3 months of OpenAI review, my ChatGPT App is live

Details

External ID
47923382
Source
HN
Company
—
Product
—
Website domain
—
Launched
April 27, 2026
Cohort
—
Upvotes
5
Upvotes percentile
0.11182519280205655
Tags
—
Fetched at
Sept. 7, 2026, 9:26 p.m.
Updated at
Sept. 7, 2026, 9:26 p.m.

Description

I run Tredict, an endurance sports training platform I've been building since 2020. OpenAI opened the ChatGPT App Directory to third-party submissions in December, and the official Tredict app is now live. The actual programming took me two weeks, but the entire process took three months.AMA on the submission process to OpenAI (timeline, review effort, what they ask for), how I solved user-authenticated content inside the iframe widgets, or why I had to remove certain tools to stay on the fitness side of OpenAI's fitness/health line.https://www.tredict.com/blog/tredict_chatgpt_app/Connect with a free ChatGPT account in a couple of clicks, then ask ChatGPT to analyse your activities, rename past sessions, or create structured workouts. Planned workouts sync to Garmin, Coros, Wahoo, Suunto and some more via Tredict. When you ask for it, an interactive Tredict view opens directly in the chat thread, showing the actual activity with charts, map and metrics, or the structured workout you just created.Two things I find interesting about this:The app uses MCP UI Apps, not just tools. Tredict's actual activity and plan views render inside the chat as interactive widgets. Most ChatGPT apps I've seen so far are tool-only, the widget pattern is still uncommon. Getting user-authenticated content into those widgets was the hardest part. The widget runs in a sandboxed iframe that has no access to the user's OAuth tokens, and there are basically no documented best practices for this yet.ChatGPT is also frugal with its context window, so it tends to fetch the activity list and skip the detailed metrics unless you nudge it. A vague "tell me about my run" gets a shallow answer, while "fetch the details and give me a detailed assessment" gets the full analysis. For multi-week plan creation Claude with the same MCP server still works noticeably better. With Claude.ai I can build full structured training plans spanning weeks or even months, with proper periodisation, mixed sport types and individualised intervals based on past activity data. ChatGPT struggles with that scope. The limit sits with the host, not the server. The interactive MCP UI Apps also work in Claude.ai, so the same activity and plan widgets render directly in the chat there too.Server lives at https://www.tredict.com/api/mcp/v2 and works with any MCP-compatible host. Honestly it works best with Claude.ai, which makes it slightly absurd that my application to be listed in Anthropic's connector directory has been pending without feedback for a while. If any Anthropic folks see this: would genuinely appreciate a status update or even a rejection with reason.

Enrichment

Theme
AI visibility and marketing tools
Vertical
Horizontal
Function
Vertical SaaS
Audience
B2C
AI stance
AI feature
Project type
Commercial product
Normalized one-liner
chatgpt app
Manually corrected
False

Could you build this?

Yes Creating a ChatGPT custom app/action that integrates with an existing platform's REST API using an OpenAPI schema definition is simple and easily vibe-coded.

Discussion

1 comment analyzed.

Concerns raised: Long review timeline (3 months) for integrations, Slow iteration loop with ~10 day response times on feedback, Auth gap inside iframe undocumented for MCP UI Apps

Feature requests: Widget support for MCP UI Apps (currently tool-only)

Competitors

Other products that read as similar to this one — 129 launches clear the similarity bar, closest 8 shown.

Attention rank: #122 of 130 (itself plus its competitors, highest first — normalized so YC and Product Hunt are compared fairly).

Launched 166 days after the earliest competitor.

Other launches for this product

Same idea, different domain

Nobody's really built a vertical saas tool for Insurance yet.