# Tessary > Tessary is an open-source agent reliability platform. It monitors every production trace, detects issues that sampled evals miss, and investigates to find the root cause. Category: open-source agent reliability for engineering teams running AI agents in production. License: Apache 2.0. Tessary has two plans: Open Source, free to self-host or to run on Tessary Cloud, and Paid, priced per customer. Both are under Pricing below. For agents: append `.md` to any page URL on this site for the same content as plain markdown, without the page around it. ## What it does AI agents often fail without throwing an error. They return a success status and fluent text, while the answer, tool call, or behavior is wrong. Standard monitoring still reads the agent as healthy. Tessary monitors every production trace, detects these failures as findings, validates which findings are real issues, and investigates the resulting cases against the available trace evidence and your repository to identify what caused the change. ## How it works Send the OpenTelemetry traces your agent already emits over OTLP. - Monitor every trace. Tessary reads the full production trace stream rather than sampling conversations for evaluation. - Detect failures and frustrated users. Focused classifiers run cheaply across the stream and create a finding when a condition is met. One of them finds conversations where users are unhappy with your agent, cheaply and in real time. Triage determines which findings are real issues; a frustration finding and a high-confidence secret leak open their case without it. - Investigate the cause. Tessary works from the failing traces, surrounding trace history, and, when connected, your repository to determine what changed. - Name the cause. Tessary reports the likely cause, the evidence behind it, and the change to make. Writing the change is yours. A regression does not need to come from a code change. Model-provider updates, upstream agents, tools, dependencies, prompts, and external APIs can change an agent's behavior without producing a diff in your repository. Tessary RCA still attributes these causes correctly. ## Pricing Two plans. Every way of running Tessary runs the same workflow on the traces your agent already emits. ### Open Source: self-host or Tessary Cloud, free It monitors every production trace, runs the built-in classifiers (drift, tool errors, secret leaks, malformed output, frustration, and groundedness), and includes cases, triage, and root-cause analysis. - Self-hosted, you run it on your own infrastructure and add your model-provider keys in the app. The only data that leaves your infrastructure is what goes to model providers on your own keys. - On Tessary Cloud, Tessary hosts it: sign up and send traces, with nothing to deploy and no model key needed to start. Tessary Cloud is free, with no credit card required. Each organization gets 10,000 traces per calendar month, 1 GB of stored trace data, 30-day trace retention, and a one-time $10 credit for triage and root-cause analysis (RCA). ### Paid: self-host or managed hosting, priced per customer Everything in Open Source, plus: - Custom classifiers, available only on Paid: not on Tessary Cloud and not in the open-source edition. You describe a failure specific to your agent in plain words, and an authoring agent reads your project's real production traces and builds the classifier with you. Before it goes live, it is calibrated: you get an agreement score measured on examples it was not tuned on. It runs on every matching session, alerts on a change in its rate rather than on every single flag, and its findings go through triage, RCA, and cases like the built-in classifiers. It runs on your own model-provider key. - Managed hosting: a dedicated instance, run by us. - Higher limits, longer retention, and support over a dedicated Slack channel. Paid has no published price or limits. To get a quote, talk to us: email akhil@tessary.ai or book a meeting at https://calendar.notion.so/meet/akhil-varma/demo. - [Talk to us](https://calendar.notion.so/meet/akhil-varma/demo) - [Pricing](https://tessary.ai/pricing) ## Answers The llms.txt file containing all the answers about Tessary and Agent Reliability. - [Answers](https://tessary.ai/answers/llms.txt) ## Tessary Cloud The four limits are under Pricing above. One trace is one agent turn: a user's message, your agent's full response, and every tool call in between. The credit does not renew. Once it is used, add your own model-provider key for further triage and RCA; ingestion, classifiers, and findings keep running. When either the monthly trace count or the stored-data cap is reached, new traces are rejected with an explicit error, not sampled or dropped silently. Trace data older than 30 days is deleted. For higher limits, talk to us: email akhil@tessary.ai or book a meeting at https://calendar.notion.so/meet/akhil-varma/demo. - [Sign up](https://app.tessary.ai) - [Documentation](https://docs.tessary.ai) ## Self-hosting Free. One command, nothing to clone. The Compose file is published to the registry as an OCI artifact beside the image: ``` docker compose -f oci://docker.io/tessaryai/tessary:compose up -d -y ``` Needs Docker Compose v2.32 or newer. Or hand this to a coding agent and it will do the install: ``` Self-host Tessary for me by following https://github.com/tessaryai/tessary/blob/main/setup.md ``` - [Self-hosting docs](https://docs.tessary.ai/self-hosting/setup) - [Setup guide for coding agents](https://github.com/tessaryai/tessary/blob/main/setup.md) - [Repository](https://github.com/tessaryai/tessary) ## Links - [Pricing (Markdown)](https://tessary.ai/pricing.md) - [Pricing (HTML)](https://tessary.ai/#pricing) - [Blog (Markdown)](https://tessary.ai/blog.md) - [Blog (HTML)](https://tessary.ai/blog) - [Privacy policy (Markdown)](https://tessary.ai/privacy-policy.md) - [Privacy policy (HTML)](https://tessary.ai/privacy-policy) - [Terms of service (Markdown)](https://tessary.ai/terms-of-service.md) - [Terms of service (HTML)](https://tessary.ai/terms-of-service) - [Data processing addendum (Markdown)](https://tessary.ai/data-processing-addendum.md) - [Data processing addendum (HTML)](https://tessary.ai/data-processing-addendum) - [Documentation](https://docs.tessary.ai) - [App: sign in, or sign up for Tessary Cloud](https://app.tessary.ai) - [Sitemap](https://tessary.ai/sitemap-index.xml)