Happy Valley

agentmash vs Tessary

agentmash and Tessary are both developer tools tools aimed at developers and small businesses. Both have a free plan.

agentmash

Shared room that warns coding agents before they edit the same file

Tessary

Open-source monitoring that finds why production AI agents fail

PricingFreemium · $20Open source
Starting price$20/moNot published
Free planYesYes
Free trial30 days—
Built forDevelopers, Small businesses, EnterpriseDevelopers, Small businesses, Enterprise
Platformsmacos, windows, linuxweb, linux
Country——
Rating——

Choose agentmash if

Engineering teams where several developers run AI coding agents on the same repository at once.

  • Pricing counts developers only, with unlimited agents
  • Free for two developers, and Team's first month is free
  • Server does not see code unless a room enables diffs

Look elsewhere if: Solo developers or teams that just need a single coding agent (Cursor) without cross-machine coordination.

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).

agentmash vs Tessary pricing

agentmash

  • Free$0Up to 2 developers, 1 private repo, 7 days of history
  • Team$20/moPer developer, unlimited private repos, 90 days; $16 billed yearly
  • EnterpriseFrom $15,000/yrSelf-hosting from a private Docker image, invoiced

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

agentmash · Key features

  • Pre-edit warnings naming the teammate, branch and task behind a change
  • Advisory path claims so agents split work before starting
  • Strict mode that blocks edits into a teammate's change until acknowledged
  • Prompts sent to a teammate's agent that run only after their approval
  • Team chat whose latest messages reach every agent before its next prompt
  • Lobby desktop app for Mac and Windows running agents side by side

Cons

  • Sign-in requires GitHub; GitLab and Bitbucket need extra setup
  • No Linux desktop app, only the CLI
  • Continue and Zed get MCP tools only, without live edits in the room

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

agentmash vs Tessary: FAQ

Do agentmash and Tessary have a free plan?

Yes, both agentmash and Tessary have a free plan; paid plans add more usage and features.

Not sure yet?

agentmash vs Tessary (2026): Pricing and Features