OrangePro

See which code your tests really protect. Prove it by breaking the code on purpose.

OrangePro maps every public function in your repository, links each one to the tests that actually call it, and ranks what's left by what it can break. For a test you care about, it breaks the function in an isolated copy and checks that the test fails. It runs on your machine, uses no AI model for scoring, and sends nothing to OrangePro. Model calls happen only if you add your own key, for optional test generation and suggestions.

npx -y @orangepro/mcp-server@latest start .

Contents

• What you get
• Why developers use it
• Quick start
• Evidence tiers
• How the ranking works
• Prove a test
• Use with your coding agent
• Configuration
• Language support
• Requirements and limits
• Privacy and network use
• Feedback
• Reference

What you get

Every run writes two reports and a spreadsheet of tests to .orangepro/:

Every function gets one of four things to do:

The one-page summary

The detailed report

Both from OrangePro run on its own repository at commit 64a5213, without a model key, so no tests were drafted. With a key, each of the top 20 shows two drafted tests, and the side panel shows their steps and code.

Why developers use it

• It tells you what a test actually checks, not just what it runs. A test that calls a function isn't necessarily checking it. opro prove replaces the function body with a fixed return value in an isolated copy and reruns your own test, unchanged. If the test still passes, it wasn't protecting that function.
• It puts consequences first. One filter shows the code paths that reach a delete or purge (cache evictions don't count); others show code that changes often, has many callers or runs on a schedule.
• It's honest about evidence. A function is "linked" only when a test calls that exact function. A test with a similar name is a lead, never coverage. Tests that only check mocks don't count.
• It's repeatable. Same commit, full git history, same config and same version give the same ranking. Each report records fingerprints, so you can tell when a change in results came from the code and when it came from the tool.
• Your coding agent can drive it. As an MCP server it gives Claude Code, Cursor, Copilot, Codex and others the ranked gaps, the suggested test location and the proof step in one loop.
• It's free, local and open source (MIT). No account, no API key for analysis, and no upload.

Quick start

cd /path/to/your/repo
# install the repo's own dependencies first (npm ci, uv sync, go mod download, ...)
npx -y @orangepro/mcp-server@latest start .
open .orangepro/short_behavior-coverage.html

Analysis, ranking and proof need no model key. Test generation is optional and uses your own key (see Model setup).

Tips for the most accurate run:

• Use a full clone, not a shallow one. Change history drives part of the ranking, and the report says when history was partial.
• Exclude what isn't product code with rank_exclude_paths (see Configuration).
• Rerun after a change. Each report says what changed since the last one. When nothing changed (same commit, files, settings, coverage and proofs), start reuses the last reports at once and says so; --fresh runs in full anyway.

What's written:

.orangepro/
├── short_behavior-coverage.html   ← one-page summary
├── behavior-coverage.html         ← detailed report: worklist, map, run details
├── tests.csv                      ← drafted tests, one row per test
├── report-data.json               ← the data both reports show (used to compare and reuse runs)
├── run-key.json, last-start.json  ← what the last run saw, so an unchanged repo is not analysed again
├── graph.json                     ← the evidence graph (deterministic)
├── ledger.json                    ← proof certificates
├── rtm.md                         ← traceability matrix
└── config.json                    ← optional per-repo settings

orangepro_generated/               ← generated tests (only with a model key); your files are never edited

Evidence tiers

Every function gets exactly one evidence label. The four things to do above are read from it.

A proof that ran and did not catch the break turns the function into Write; a proof made before the code changed turns it back into Prove.

What OrangePro doesn't count, so linked numbers are a floor, not a coverage percentage:

• tests that only assert on mocks;
• calls made over HTTP or from end-to-end suites;
• in Python, objects that reach a test only through a fixture.

Check the tests before writing new ones for a flagged path.

"Proven 0" is normal on a first run. Proof runs your tests, so it happens only for the functions you choose, or within the attempt budget of opro start.

How the ranking works

Each unproven function gets an OrangePro Risk Score, ORS = P × I × D:

• P: how likely it is to change. Change history, fan-out, new code and size.
• I: what it can break. Incoming references, entry-point position, data sensitivity, and a floor for paths that reach a delete or purge within two calls.
• D: how hard a break would be to notice. Evidence tier (a linked test or a coverage run makes a break easier to notice than a name match or nothing), and whether it runs unattended (jobs and schedulers).

The score sets the order of work. It is not a defect probability. The weights are fixed and no AI model is involved. The report shows the inputs behind every row.

Prove a test

# Python: the mutation value is derived from the function (return annotation or its observed result)
opro prove-loop --target-symbol 'sym:app/billing/invoices.py#void_invoice' \
  --test 'tests/test_invoices.py::test_void_marks_invoice_void' --replacement sentinel

# TypeScript / JavaScript: give the inert body to substitute
opro prove-loop --target-symbol 'sym:src/orders.service.ts#OrdersService.cancel' \
  --test src/orders.service.spec.ts --replacement 'return null;'

• Proven: the test passes on the original code and fails at its own assertion on the broken copy.
• Not proven: the test still passes on the broken copy, so it doesn't protect that function. That's a finding too.
• Unrunnable: setup failed. This is never counted either way.

Find weak tests without a model key:

opro roast .   # passing tests whose targeted mutant still survives

Use with your coding agent

OrangePro runs as an MCP server. Add it to your client's config:

{
  "mcpServers": {
    "orangepro-local": {
      "command": "npx",
      "args": ["-y", "@orangepro/mcp-server@latest", "mcp"]
    }
  }
}

A prompt that runs the whole loop:

"Use orangepro_start, then orangepro_find_test_gaps. For the top gap, write a test at the suggested path, run it, then call orangepro_prove_loop and tell me whether it was proven."

Configuration

Optional. Put it in .orangepro/config.json in the repository, or in ~/.orangepro/config.json for defaults across repositories. Every setting that changes the ranking is shown in the report.

{
  "classification": {
    "rank_exclude_paths": ["ui/**", "docs/**", "scripts/**"],
    "test_support_paths": ["internal/testutil/**"],
    "destructive_sinks": ["archive*"]
  },
  "tuning": { "churn_window_days": 180 },
  "proof": { "python_runner": "auto", "attempt_limit": 20 },
  "overrides": [
    { "symbol": "sym:src/legacy/shim.ts#shim", "action": "suppress", "reason": "generated shim, not product code" }
  ]
}

• rank_exclude_paths removes paths from the ranking. They are still counted as behaviors.
• destructive_sinks adds delete-like calls for your codebase.
• Overrides (suppress, pin, reclassify) each require a reason, and the report lists them.
• Weights and tiers can't be configured.

Language support

• "Name match only" means a test file or test name that looks like the function makes it Unconfirmed (Check). No call is traced, so these languages never reach Linked or Proven today.
• TypeScript and JavaScript are parsed with the TypeScript compiler; the other languages with tree-sitter.
• Python proof runs pytest through the repository's own environment: an existing .venv or venv, then uv or poetry when their lock files are present, else python -m pytest. Set proof.python_runner to use your own command.
• Java proof needs Maven (Surefire) and JUnit 5. Gradle and JUnit 4 projects are mapped and linked, but not proven yet.
• Not traced yet, so tested code can show as Unconfirmed: calls through Go test-suite methods and helper constructors, dependency injection that is wired at runtime, reflection, and calls made over HTTP or RPC.

Requirements and limits

• Node.js 20 or newer, on macOS or Linux. Windows isn't tested: proofs use POSIX paths and symlinks.
• Git, for change history. Without it, or in a shallow clone, the ranking uses structure only and the report says so. A folder that isn't a git checkout always runs in full.
• Install the repository's dependencies first (npm ci, uv sync, go mod download, mvn -q install, …). Proof runs your own tests in an isolated copy and needs them to pass there.
• What's read: source and test files, skipping anything in .gitignore or .orangeproignore (negations with ! aren't supported), the usual build and dependency folders (node_modules, vendor, dist, build, target, coverage, .venv, …), files over 1 MB, and generated code (files marked Code generated … DO NOT EDIT). Up to 100,000 files; ORANGEPRO_MAX_FILES lowers that and ORANGEPRO_MAX_ANALYZE_MS sets a time limit for the scan.
• Test drafting covers the 20 highest-priority functions, two tests each, in the order the worklist shows, and the reports show those 20. Drafts are kept until the function's code changes.
• What counts as "nothing changed" for reusing a run: the commit, every modified or untracked file that git doesn't ignore, OrangePro's settings and ignore files, coverage files, the proof ledger, the start options, whether a model key is set, and the analysis version. A run whose test drafting failed on a provider error (out of credits, rate limit) runs again in full.
• The CSV column mapping follows each tool's CSV importer (see Importing tests.csv). Check the import preview the first time.

Privacy and network use

• Nothing about your code or your runs is sent anywhere. There is no usage telemetry.
• Source is read in-process and never stored or uploaded. Reports and the evidence graph contain metadata, not your source.
• Your source files are never edited. Proofs run in an isolated copy.
• Model calls happen only if you configure a key, and they go directly from your machine to the provider you chose. Keys are read from your environment or from a .env.provider.local, .env.local or .env file in the repository, and OrangePro never writes them anywhere. opro setup saves only the provider and model name.
• With a key, the reports and tests.csv include the tests your model drafted, and the prompts include the function names, files and evidence they're based on.
• Reports load nothing from the network. The only outbound links are ones you click.

Feedback

Reports include a Give feedback link and a This looks wrong link on each finding. Once in a while, after the findings, they also ask whether the report helped.

• The links carry nothing about your project. The form sends only what you review and submit.
• You stay anonymous unless you leave an email.

opro feedback          # print the link and your settings
opro feedback off      # stop the "Did this help?" question (links stay)
ORANGEPRO_FEEDBACK_URL=off   # hide every feedback link

The question appears at most once every 14 days (ORANGEPRO_FEEDBACK_COOLDOWN_DAYS). That preference is stored only on your machine. MCP clients get the link as optional result metadata (_meta["ai.orangepro/feedback_url"]), and your agent is never asked to prompt you for feedback.

Reference

opro                          # same as opro start .
opro start . --no-ai --no-auto   # analyze + reports, no model calls, no proof attempts
opro start . --fresh          # run in full even when nothing changed since the last run
opro start --base main        # scope to a branch diff
opro analyze                  # build the evidence graph and reports
opro gaps --limit 10          # top unproven behaviors, ranked
opro prove-loop ...           # mutation proof for one function (see above)
opro roast .                  # find tests whose mutant survives (no key needed)
opro doctor --proof           # why top targets aren't proven yet
opro generate --base main     # tests for what this branch changed (needs a model key)
opro rtm                      # traceability matrix
opro export                   # metadata-only evidence pack
opro coverage                 # find or generate runtime coverage artifacts
opro feedback [on|off]        # feedback link and invitation setting
opro mcp                      # run as an MCP server (stdio)

{
  "artifacts": {
    ".orangepro/coverage/unit.coverprofile": { "suite": "unit", "command": "make unit-test-coverage" },
    ".orangepro/coverage/integration.coverprofile": { "suite": "integration", "command": "make integration-test-coverage" }
  }
}

opro generate --base main     # tests for what this branch changed (read-only git diff)
opro generate --changed       # current branch vs its base
opro generate --pr 1234       # checks out PR #1234 (asks first; refuses on a dirty tree)

Hosted platform

This repository is the free local tool. The OrangePro platform adds:

• a persistent graph across PRs and repositories;
• CI gates on evidence and risk changes;
• requirement and incident correlation;
• team dashboards.

Contributing

git clone https://github.com/OrangeproAI/orangepro-mcp.git
cd orangepro-mcp && npm ci && npm run build
npm test

PRs welcome. Please open an issue first for large changes.

MIT License · orangepro.ai