Tavily
TAVILY_API_KEY | ✅ | ✅ | 🟢 forever | 1,000 API credits / month, recurring, no credit card. | Pay-as-you-go $0.008 / credit |
Firecrawl
FIRECRAWL_API_KEY | ✅ | ✅ | 🟢 forever | 1,000 credits / month, recurring — no cost, no card, no hassle. | Hobby $16–19/mo for 5k credits |
Brave Search
BRAVE_API_KEY | ✅ | — | 🟢 forever / card caveat | $5 in free credits every month, recurring. | Search $5 / 1k requests |
Querit
QUERIT_API_KEY | ✅ | — | 🟢 forever | 1,000 API requests / calendar month on the Free tier. | Pay-as-you-go US$4 / 1,000 API requests |
SearXNG
searxng.base_url | ✅ | — | 🟢 self-hosted | Free if you self-host; no vendor API bill. | Open-source/self-hosted. Your cost is the server, maintenance and upstream engine reliability. |
Keenable
KEENABLE_API_KEY | ✅ | ✅ | 🟢 keyless / authenticated allowance | Keyless public pool plus monthly authenticated credit allowance (size unpublished). | Unauthenticated: 1,000/hour, 10 rps/IP, unmetered. Authenticated: monthly free allowance then paid packages. |
DonSeTch
DONSETCH_BIN | ✅ | ✅ | 🟢 local / no provider key | Separate local stdio MCP process; no provider request fee. | Your machine, bandwidth, browser runtime and maintenance. |
Octen via Monid
MONID_API_KEY | ✅ | — | ⚪ no free-tier claim | Monid API key and wallet balance required. | See Monid for current pricing and terms. |
TinyFish
TINYFISH_API_KEY | ✅ | — | ⚪ account required | Search requests do not consume credits; API access required. | Published Search limit starts at 30 requests/minute. |
You.com
YOU_API_KEY | ✅ | ✅ | 🟡 one-time | $100 free API credit on a key; You.com also lists 100 queries/day no-key on its own site. | Search $5 / 1k calls; Answer $5 / 1k |
Parallel
PARALLEL_API_KEY | ✅ | ✅ | 🟢 recurring | Up to 5,000 requests / month free, plus up to $80 signup and $5 / month. | Search turbo/fast $1 / 1k; basic/advanced $5 / 1k |
Serper
SERPER_API_KEY | ✅ | ✅ | 🟡 one-time | 2,500 free credits, no credit card. | Volume packs: $1.00 / 1k at 50k credits down to $0.30 / 1k at 12.5M credits |
Exa
EXA_API_KEY | ✅ | ✅ | 🟡 credit-based / caveated | $20 signup + $10 credits / month, no card. | Search $7 / 1k requests |
SerpBase
SERPBASE_API_KEY | ✅ | — | 🟡 one-time | 100 free searches to start, no card; no-key preview capped to 5 organic links. | Starter Boost $3 / 10k expires after one month. Standard prepaid packs $0.50–$0.30 / 1k, no expiry. |
Linkup
LINKUP_API_KEY | ✅ | ✅ | 🟢 recurring credits / eligible accounts | Professional-email signups receive $20 credit; eligible accounts are topped back up to $20 each month. | Search $0.005–$0.006 / request for standard/fast |
Perplexity Sonar API
PERPLEXITY_API_KEY | — not in WSP 3.x | — | 🔴 none | No durable free API tier found. | Search/Sonar request fees roughly $5–$22 / 1k depending context/model, plus token pricing. |
Kilo Code — Perplexity bridge
KILOCODE_API_KEY | — not in WSP 3.x | — | ⚪ depends | Depends on your Kilo account and billing. | Usage is billed through the configured Kilo/provider account |