telemetry.dev vs Tessary
telemetry.dev and Tessary are both uptime & monitoring tools aimed at developers and small businesses. Both have a free plan.
OpenTelemetry-based tracing, cost tracking and evals for AI agents
Open-source monitoring that finds why production AI agents fail
| Pricing | Freemium · $25 | Open source |
| Starting price | $25/mo | Not published |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Built for | Developers, Small businesses | Developers, Small businesses, Enterprise |
| Platforms | web | web, linux |
| Country | — | — |
| Rating | — | — |
Choose telemetry.dev if
Small teams building AI agents who want affordable tracing, cost tracking, prompt management and evals in one OpenTelemetry-based tool.
- Standard OpenTelemetry avoids proprietary instrumentation lock-in
- Free plan needs no credit card
- Simple per-workspace pricing with unlimited seats on Team
Look elsewhere if: Organizations that need self-hosting, compliance paperwork or full-stack infrastructure monitoring (Datadog, Sentry).
Choose Tessary if
Engineering teams running AI agents in production with OpenTelemetry traces who want every trace checked and failures explained.
- Apache 2.0 open source with free self-hosting
- Checks every trace instead of a sampled subset
- RCA links failures to specific commits when a repo is connected
Look elsewhere if: Teams that want a mature, fully supported observability suite or an eval-first workflow (Datadog, Braintrust).
telemetry.dev vs Tessary pricing
telemetry.dev
- Free$0/mo30,000 units/mo, 14-day retention, 1 project, 2 seats
- Pro$25/mo500,000 units/mo, 30-day retention, 5 projects, 5 seats
- Team$50/mo2M units/mo, 90-day retention, unlimited seats, priority support
Tessary
- Open Source$0Self-host with Docker Compose; all core features
- Cloud Free$010k traces/mo, 1 GB, 30-day retention, $10 one-time RCA credit
- PaidCustomCustom classifiers, managed dedicated instance, Slack support
telemetry.dev · Key features
- One trace per request or agent run with spans for every model and tool call
- Token, cost, latency and error tracking per span
- TypeScript and Python SDKs plus any OTLP/HTTP exporter
- MCP analytics with failures and p95 duration by method and tool
- Prompt versions, labels and rollouts without a deploy
- Evals on datasets with LLM judges, code checks and human review
Cons
- No self-hosted option
- No legal entity, address or compliance certifications published
- Free retention is only 14 days
Tessary · Key features
- Classifiers run on every production trace with no sampling
- Built-in checks for drift, tool errors, secret leaks and malformed output
- LLM triage groups real deviations into trackable cases
- Root-cause analysis over failing traces and your GitHub repository
- OTLP ingestion over HTTP and gRPC with OpenTelemetry gen_ai conventions
- PII redaction before traces are stored
Cons
- Very new project with a short track record
- Paid plan prices are not published
- Frustration classifier requires your own OpenRouter or TypeSafe key
telemetry.dev vs Tessary: FAQ
Do telemetry.dev and Tessary have a free plan?
Yes, both telemetry.dev and Tessary have a free plan; paid plans add more usage and features.