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Spanlens

Monitors LLM API calls across providers, tracking costs, latency, and traces through a single proxy endpoint.

Developer toolsAPIMonitoringFor developers
spanlens.io ↗XLaunched on Product Hunt · 2026-06-03
At a glanceswept 2026-09-19
For
Developers and teams shipping LLM features who need cost and performance monitoring.
Price
Free plan · From $29/mopricing page, read 2026-09-19
Use
Emerging≈ 5 visits a month · estimate, 2026-09 · 127 npm installs a month
Activity
Actively maintainednothing dated on the site
Company
founding year not on record
Runs as
API
What people do with itread off spanlens.io on 2026-09-19
  • Track cost and latency across LLM API providers
  • Debug agent traces with nested spans and tool calls
  • Compare prompt versions on real traffic before rollout
Alternatives in Developer toolsby use, among tools still maintained
  • OneUptimeMonitors infrastructure and applications, detects incidents in seconds, pages on-call engineers, and opens fix pull requests.

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    ≈ 221k visits/mo
  • True WatchMonitors applications, infrastructure, and AI workloads with correlated telemetry and AI-assisted diagnostics.

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  • World MonitorStreams geopolitical, shipping, market and infrastructure signals onto a live map with correlation alerts.

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  • OpenObserveIngests and correlates logs, metrics, and traces across infrastructure layers for incident investigation and root cause analysis.

    EstablishedActively maintained

    ≈ 4.6k visits/mo
  • RespanRoutes LLM requests through one gateway to reach multiple models with observability, caching, and evaluations.

    EstablishedActively maintained

    ≈ 1.1k visits/mo
  • MotadataUnified observability and IT service management platform combining infrastructure monitoring, application performance, and incident management.

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All Developer tools tools →

Questions this page answers
  • What is Spanlens?

    Monitors LLM API calls across providers, tracking costs, latency, and traces through a single proxy endpoint.

  • Who is Spanlens for?

    Developers and teams shipping LLM features who need cost and performance monitoring.

  • How much does Spanlens cost?

    Spanlens has a free plan; paid plans start at $29/mo, per its pricing page on 2026-09-19.

  • Do people use Spanlens?

    Emerging: ≈ 5 visits a month · estimate, 2026-09 · 127 npm installs a month.

  • Is Spanlens still maintained?

    Actively maintained.

  • What are alternatives to Spanlens?

    In Developer tools, by use: OneUptime, True Watch, World Monitor, OpenObserve, Respan, Motadata.

How we read a tool

No votes, no reviews, no vendor claims. Every week a crawler reads each tool's own site and a few public registries, and the words on the card are bands over what it read.

  • Use: visits to the site (estimated), installs from npm and PyPI, presence in Chrome's usage report.
  • Activity: the newest release on GitHub, npm or PyPI; the newest dated page on the site; open roles on a public jobs board.
  • Price: the vendor's own pricing page, read with the date. A figure is printed only when it is on that page.
  • The line and the use cases are written by us from the homepage, one row at a time, and refused when they repeat the vendor's marketing.

How AI assistants read each site — the reading vendors ask us about — is on each tool's own visibility page.