Add Social Fetch to the catalog

[socialfetch]

Summary

• List Social Fetch (socialfetch) as a Social media API-key provider: x-api-key header, https://api.socialfetch.dev, probe GET /v1/whoami.
• Curate 14 endpoints that overlap existing capabilities (TikTok / Instagram / YouTube / X profiles, posts, search) plus the two free account probes.
• Wire the tier-4 platform-key slot (platform_key_socialfetch) and a Growth-pack FX rate ($47 / 25,000 credits = $0.00188). Enabling TREG_PLATFORM_PROVIDERS plus the env key is an ops decision.

Contact: support@socialfetch.dev

Probe (live 2026-09-15)

• Bogus key GET /v1/whoami: HTTP 401 {"error":{"code":"unauthorized","message":"Invalid API key."}}
• Valid key: HTTP 200, meta.creditsCharged=0

Self-verification ledger (2026-09-15)

Meter: meta.creditsCharged on each response. No verified: stamps or example files in this PR.

endpoint	http	test target	credits observed	catalog price	matches?	evidence
socialfetch.account.identity	200	(none)	0	free	yes	meta.creditsCharged=0
socialfetch.account.usage	200	(none)	0	free	yes	meta.creditsCharged=0
socialfetch.tiktok.user.profile	200	handle=tiktok	1	1 credit	yes	lookupStatus=found, meta.creditsCharged=1
socialfetch.tiktok.user.videos	200	handle=tiktok	1	1 credit	yes	meta.creditsCharged=1
socialfetch.tiktok.video.detail	200	official @tiktok video URL	1	1 credit	yes	lookupStatus=found, meta.creditsCharged=1
socialfetch.tiktok.video.comments	200	same video URL	1	1 credit	yes	lookupStatus=found, meta.creditsCharged=1
socialfetch.tiktok.search.videos	200	query=coffee	1	1 credit	yes	meta.creditsCharged=1
socialfetch.instagram.user.profile	200	handle=instagram	1	1 credit	yes	lookupStatus=found, meta.creditsCharged=1
socialfetch.instagram.user.posts	200	handle=instagram	1	1 credit	yes	lookupStatus=found, meta.creditsCharged=1
socialfetch.youtube.channel.profile	200	handle=@youtube	1	1 credit	yes	lookupStatus=found, meta.creditsCharged=1 (bare YouTube 502'd; @YouTube works)
socialfetch.youtube.video.detail	200	first YouTube video URL	1	1 credit	yes	lookupStatus=found, meta.creditsCharged=1
socialfetch.youtube.search.videos	200	query=coffee	1	1 credit	yes	meta.creditsCharged=1
socialfetch.x.user.profile	200	NASA?by=handle	1	1 credit	yes	lookupStatus=found, meta.creditsCharged=1
socialfetch.x.user.posts	200	NASA tweets limit=5	1	1 credit	yes	lookupStatus=found, meta.creditsCharged=1

Billing model: prepaid credits (PAYG packs never expire; optional subscriptions). Pricing: https://www.socialfetch.dev/pricing. Rate card: OpenAPI x-socialfetch-pricing at https://api.socialfetch.dev/openapi.json. Docs: https://www.socialfetch.dev/docs.

Full-surface map (220 OpenAPI paths)

Catalogued (14): /v1/whoami, /v1/balance, /v1/tiktok/profiles/{handle}, /v1/tiktok/profiles/{handle}/videos, /v1/tiktok/videos, /v1/tiktok/videos/comments, /v1/tiktok/search, /v1/instagram/profiles/{handle}, /v1/instagram/profiles/{handle}/posts, /v1/youtube/channel, /v1/youtube/videos, /v1/youtube/search, /v1/twitter/profiles/{handle}, /v1/twitter/profiles/{handle}/tweets.

Excluded (reason):

• Remaining TikTok / Instagram / YouTube / X list, comment, transcript, download, shop, ad-library, follower, and search variants — overlap already covered by the cheapest 1-credit profile/post/search jobs; heavier hostMedia / downloadMedia riders left off the curated set.
• Facebook, LinkedIn, Reddit, Threads, Telegram, Pinterest, Twitch, Rumble, Bluesky, Truth Social, GitHub, Hacker News, Linktree, Spotify, Apple Music, SoundCloud, Amazon, Google Ads Library, web extract/crawl/search — either no shared capability shelf yet or a second-wave extended ingest from the published OpenAPI.
• /v1/monitors*, /v1/webhook-*, /v1/ask — product/account management, not public social lookups.
• /health — infra.

Happy to add an ingest_socialfetch() extended tier next; OpenAPI is stable at https://api.socialfetch.dev/openapi.json.

Test plan

• uv run --frozen python scripts/catalog_validate.py → OK, 0 errors
• Targeted pytest: registry, key-provider offerable, logo, platform_eligible
• Maintainer live bogus-key POST /connections/token + catalog_verify.py with an independent key (email support@socialfetch.dev for a grant)

A test credential can be arranged over that contact email. No credentials are in this PR.