agent-transcript

YouTube search and transcript API for AI agents — free search and free caption transcripts, plus paid search at $0.005/call and paid transcript at $0.01/call in USDC on Base via x402. No account, no API key.

Base URL: https://agent-transcript.fly.dev

Give a YouTube URL, get a structured transcript back as JSON: full text plus timed segments. No account, no API key, no signup.

When to use this skill

Use it when an agent needs to read what a YouTube video actually says — for research, summarising, fact-checking against a video, or finding where in a video something was said — without downloading the video.

Endpoints

GET /agent/v1/youtube-search

Free YouTube search. No payment, no API key.

• Query: q=<query>&max_results=5
• Returns: structured video results as JSON, cost_usd: 0.
• Example: GET https://agent-transcript.fly.dev/agent/v1/youtube-search?q=Rick+Astley&max_results=3

GET /agent/v1/transcript

Free transcript from a video's own captions. No payment, no API key.

• Query: url=<YouTube URL>&lang=auto|en|zh
• Returns: JSON with video_id, transcript, segments[{start, end, text}], source, cost_usd.
• Free caption tiers only.

GET /agent/v1/youtube-search-paid

Paid YouTube search, $0.005 per call, USDC on Base via x402. Live-confirmed 2026-10-28 19:32 Beijing: a bare request returns the x402 payment-required challenge (x402Version 1, scheme exact, network eip155:8453, maxAmountRequired 5000, Base USDC asset) — not a Not Found. Pay and retry with the payment header to get search results. The pay-to address is read from the live 402 at call time and is deliberately not hard-coded in this skill file.

GET /agent/v1/transcript-paid

Paid transcript, $0.01 per call, USDC on Base via x402.

• Query: url=<YouTube URL>&lang=auto|en|zh
• Without payment it returns HTTP 402 with payment requirements.
• Pay in USDC on Base, retry with the X-PAYMENT header, get the transcript.
• Discovery: /llms.txt, /.well-known/agent.json, /.well-known/x402, /x402.json, /openapi.json, /health.

Payment

• Rail: x402, USDC on Base (network eip155:8453).
• Paid search: $0.005 per call. Paid transcript: $0.01 per call. Free search and free transcript: $0.
• Buyers pay the seller wallet directly; no account or API key is issued.
• Honest limit, do not remove: a real $0.01 payment through a facilitator has not yet been settled and verified, and this skill is not listed as settlement-verified on any x402 directory. Do not claim otherwise.

Errors

• Video with no captions: error=no_captions, HTTP 404. The free endpoint never silently falls back to a paid service.
• Paid endpoint without payment: HTTP 402 with payment requirements.
• Bad payment header on a paid endpoint: HTTP 402, no transcript returned.

Free routes (liveness)

• GET /health — free, no payment, no auth.
• GET /agent/v1/youtube-search — free.
• GET /agent/v1/transcript — free (caption tiers only).

What this skill does NOT include

• No MCP wrapper: this is a plain HTTP API skill, not an MCP server. MCP directories (Smithery, Glama, official MCP Registry) are a separate line and would need an MCP wrapper first.
• The pay-to wallet address is not hard-coded here; agents read it from the live 402 challenge at call time, as the public API already does.