EvalView MCP
Snapshot tests for AI agents: records tool calls today and tells you when they silently change after an edit
- 142 ★ on the repository
- Last commit
- Apache-2.0
Extended access
Why this level
- A check runs your agent and paid API calls and agent actions really happen
- The LLM judge sends answer texts to an external provider
Install
- Works in
In your terminal, with SkillFoxx CLI
npx skillfoxx add mcp/evalviewDetects the agents on your machine, shows the access level and pins the version.
Other ways to install
Access and checks
How we reviewExtended accessThe tool runs code or makes network calls and only reads external data.
- A check runs your agent and paid API calls and agent actions really happen
- The LLM judge sends answer texts to an external provider
This is third-party code. Review the repository files before installing.
What it does
EvalView records what an agent does now: which tools it calls, in what order, with what parameters and what it returns. `evalview snapshot` saves that picture as a baseline and `evalview check` compares the whole trajectory against it after any edit, not just the final string. The result is `PASSED`, `TOOLS_CHANGED` or `REGRESSION` when quality drops. The deterministic comparison of tools and sequence works offline and without keys, and an LLM judge is added for answer quality scoring. Agents connect from LangGraph, CrewAI, OpenAI, Claude, Mistral, Ollama, MCP or any HTTP API. CI has a GitHub Action with a pull request comment. The MCP server starts with `evalview mcp serve` and its tools include `create_test`, `run_check`, `run_snapshot`, `list_tests`, `validate_skill`, `run_skill_test`, `compare_agents` and `replay`.
Who it is for. Developers of agents on LangGraph, CrewAI and custom stacks who want to catch silent regressions after a model swap or a prompt edit.
Good fit when
- The model or provider updated and you must make sure the agent calls the same tools in the same order
- A one-line prompt edit may have broken a clarifying question and string tests do not see it
- Every pull request should block on regression and get a comment with diffs
- Agent skills are checked with `validate_skill` and `run_skill_test` over MCP
Not a fit when
- You need exact assertions on answer content: the tool catches behavior drift and does not verify correctness
- There is no agent yet: there is nothing to snapshot and a working agent comes first
- You need model benchmarks on shared datasets: EvalView tests your agent and not models in general
Example request
Record the current agent behavior as a baseline, make a prompt edit and show which tests changed their tool callsMCP
- Transport
- stdio
- Authentication
- not required
Environment variables
OPENAI_API_KEYsecret- Key for the LLM judge; deterministic comparison works without it.
ANTHROPIC_API_KEYsecret- Anthropic key for the judge, optional.
Limitations
Running the agent can still cost money in the backend: `--no-judge` turns off the judge and not calls to your agent. Embedding-based comparison is opt-in. The OpenAI Assistants adapter is outdated because the API shut down on August 26, 2026, and the Responses API migration is not in the published 0.8.1 and exists only in source. The project is young and built mostly by one developer. The internal run report has trust warnings that the authors treat as a reason to investigate and not as proof. Install with `pip install evalview` and the license is Apache 2.0.
How to disable. Remove the `evalview` entry from `.mcp.json` or run `claude mcp remove evalview`, and uninstall the package with `pip uninstall evalview`.
FAQ
How does a behavior snapshot work?
`evalview snapshot` saves the agent trajectory as a baseline and `evalview check` compares the current one with it: tools, parameters, order and output. The result is `PASSED`, `TOOLS_CHANGED` or `REGRESSION`.
Is an API key required?
No, the deterministic tool and sequence comparison works offline. An LLM judge for answer quality needs a key such as `OPENAI_API_KEY`.
How do I connect the MCP server?
With `claude mcp add evalview -- evalview mcp serve` after `pip install evalview`. The transport is stdio.
How do I connect it to CI?
Through the GitHub Action `hidai25/eval-view@v0.8.1`: it adds a pull request comment with diffs, cost and latency deltas and a pass or fail gate.
Which agents are supported?
LangGraph, CrewAI, OpenAI, Claude, Mistral, Ollama, MCP and any HTTP API, for example `evalview check --agent http://localhost:8000/invoke`.
Discussion
No questions or reviews yet.
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README in short
The headline and backstory: the agent looks fine but silently changes behavior after an edit. Then a quick start with `snapshot` and `check`, a comparison with Jest snapshots, OpenAI migration notes, CI setup, library use and a list of extra features.