MCP server: One MCP server.

Tewip

@hmamut39MCP server · External

Proves software work: triages failing tests, checks whether a test can fail, and reads migrations.

Software testingv0.49.0Apache-2.0TypeScript
Freeno charge per call

Runs on your machine from its package; the steps are below.

What it does

  1. Reads
  2. Writes
  3. High impact

Not assessed yet.

What it costs

Free

Odel charges nothing per call. The publisher may charge for its own service.

Runs locally over stdio

This server isn't hosted — your MCP client launches it from a package registry. Use one of the commands below, or drop the config into your client (e.g. Claude Desktop).

npmtewip-aiv0.49.0

Run

npx -y tewip-ai

MCP client config

{
  "mcpServers": {
    "tewip": {
      "command": "npx",
      "args": [
        "-y",
        "tewip-ai"
      ]
    }
  }
}
README54 min read

Tewip (Uyghur téwip, تېۋىپ: healer, doctor) is the layer that proves software work - written by a person or by an agent.

Created and maintained by Mamuti Aishan (Hasan) (@hmamut39).

It finds why each failing test failed (a real bug, a flaky test, the environment, test data, or a changed selector), says whether a test could ever fail at all, breaks your code to find out whether the tests would notice, reads what a migration will do to a live database, and gives one verdict on whether a change is done. Every answer carries its evidence and names what decided it: a deterministic rule, the AI model, or a person's correction.

What makes it worth installing is what it refuses to say. It answers "cannot say" rather than guessing, it will not narrow a test run it cannot prove safe to narrow, and every report ends with what it did not check. Each number below was measured on strangers' real code, never on fixtures.

It works for every stack: Node.js (node:test, Jest, Vitest, Mocha), Python (pytest, unittest), Java and Kotlin (JUnit, TestNG), Go, .NET, Ruby, PHP and Rust, each checked against its real runner's report (the full list), plus Playwright in depth with traces, selector drift and verified fixes. It also reads the failure wording of the browser and component-test tools on top of those runners (Selenium, WebdriverIO, Cypress, Testing Library for React, Vue and Angular, Vue Test Utils, jest-dom and Jasmine), checked against more than 500 real messages from public projects.

WhereHow
Terminalnpm install -g tewip-ai, then tewip explain report.xml, tewip ci owner/repo --pr 12, tewip mcp
VS Code, Cursor, Windsurf, VSCodiumthe Tewip extension (download): registers Tewip with the editor's AI assistant and adds six commands - explain a report, why CI failed on this branch, the risk review of your change, which flaky tests to quarantine, the security check, and what your corrections add up to
JetBrains, Claude, other AI assistantsadd the MCP server tewip mcp: fifteen tools, including has this happened here before?, is this requirement covered and passing? and what should be done next about this goal? (see editor setup)
Any modelOpenAI, Claude, Gemini, Azure, or a model on your own machine with Ollama (no account, nothing leaves the computer): TEWIP_PROVIDER
GitHub CIthe Tewip Action: a comment on every pull request, an optional merge gate, verified fix PRs (QUICKSTART)

Formerly triage-agent: the repository moved to hmamut39/tewip, and GitHub redirects the old address. See ROADMAP.md for the plan.

Status: phases 1 to 14 are built; the two auto-fix phases (5 and 8) are the ones still in progress. Tewip collects failures from any framework, diagnoses them with rules first and a model only for what rules cannot settle, and turns that into work for each role: a CI comment and merge gate, test plans and verified tests, a flake dossier, a PR-risk review, security scanning, tickets in Jira, Rally, GitHub Issues, Azure Boards or Linear, checks generated from a Figma design, specifications written for people, and - opt in, and only when proved - fixes to test or application code. It runs live in GitHub CI and answers questions from AI assistants through MCP. On fresh real Gutenberg CI failures, with the pipeline frozen before labelling, accuracy is 93.4%; across six real datasets it ranges from 86.1% to 99.7%, and the caveats are in eval/README.md.

What it costs

Most failures never reach a model. On 3,556 real CI failures from six public projects, the deterministic rules answered 75.1% on their own - and on the labelled ones they answered correctly 1,979 times out of 2,012 (98.4%). A rule-answered failure costs nothing, explains itself, and gives the same answer every time.

Only the remaining quarter is sent to a model, so triaging 1,000 real failures costs about $1.12 at gpt-5.4-mini's published price. That is measured, not estimated: three real uncached calls on held-out failures billed 3,624 prompt and 499 completion tokens each. A real week costs less, because a failure that repeats is answered from cache, and a failure someone has corrected never goes to the model again.

Tewip prints what every command costs, caps its own spend, and works with no key at all - the rules run on their own and everything they cannot settle is left as UNKNOWN rather than guessed.

Start here

bash
npm i -g tewip-ai
cd your-project
tewip

tewip on its own looks at your project and names the two or three commands that will tell you something, with your own paths in them — and says plainly what it cannot answer here. It reads the directory and stops: nothing is run, nothing is written, about a second.

Here is what Tewip can tell you about **this** project, in the order worth doing.

**1. `tewip vouch`**
282 test files here (282 JavaScript or TypeScript). This reads them and names the ones
that cannot fail - no model, a second or two.

**2. `tewip schema --diff main...HEAD`**
165 migrations here (165 SQL). This says what a change would do to a live database
before it runs.

## What it will not do here
- No k6, JMeter or Lighthouse report was found. Tewip judges one you produce; it does
  not run load tests itself.

Everything below is the full list, for when you want it.

Use it in your project

Giving it to your team (or another company): TEAM-GUIDE.md — what to install, what each role uses it for, and what it never does.

Putting it on a real repository: QUICKSTART.md — ten minutes, copy-paste, and what to check on the first failing run.

1. In GitHub CI (developers, SDETs, DevOps)

Tell Playwright to write a blob report in CI. It's a built-in reporter, so there's no triage-agent code in your config:

ts
// playwright.config.ts
reporter: process.env.CI ? [['list'], ['blob']] : 'list',
use: { trace: 'retain-on-failure' },

Then add one step after your tests:

yaml
permissions:
  contents: write        # only needed for autofix
  pull-requests: write
  issues: write
  actions: read          # lets it read the failed job's log when no test report was written

steps:
  # ... checkout, install, npx playwright test ...
  - name: triage-agent
    if: always()
    uses: hmamut39/tewip@main
    with:
      openai-api-key: ${{ secrets.OPENAI_API_KEY }}   # optional: without it only the rules run
      autofix: 'true'                                  # optional: verified locator-fix PRs

Run the verdict verbs in CI (Phase 38, new) — one step, as many checks as you want:

yaml
- uses: hmamut39/tewip@main
  with:
    mode: check
    checks: schema, access, vouch     # or: done, standards, perf, or `all`
    gate: blocking                    # optional: fail the job on what a verb calls blocking

Every check runs even when an earlier one found something, so a pull request gets the whole picture in one push. The gate is deliberately narrower than the report: it fails only on what the verb itself calls blocking, because a gate that fires on advice teaches a team to pass continue-on-error. A check with nothing to look at says so and never fails the job — no migrations in the diff is not a pass.

Use @main or v0.46.0 or later. Every tag before that shipped an action.yml whose description contained an unquoted colon, which YAML reads as a nested mapping — the runner answered "Failed to load action.yml" and the action never ran. It is fixed, and there is now a test over the manifest so it cannot come back.

On every run, the action:

  • Developers: posts one diagnosis comment on the pull request and keeps it updated. For each failure it says whether the change likely caused it, why, and what to do next.
  • SDETs: writes the triage board into the job summary.
  • DevOps: collects environment failures (server errors, connection resets, outages) in one GitHub issue, and each new run adds a single grouped comment to it.
  • The tests in the pull request: on a PR it reads the test files the change touched and says which of them could never fail - an unfinished expectation, a value compared with itself, a test that discards its own failure, one that never runs. It says nothing when they are all sound, and it says it even on a green run, because "all tests passed" is the exact sentence that needs qualifying when one of them cannot fail. Needs fetch-depth: 0 on actions/checkout so the diff can be read; without it the section is skipped rather than guessed at. Any such test also enters the attestation as a refusal, so a release decision taken from the bundle cannot rest on a test that proves nothing.
  • What the change would slip past (prove: true): breaks the source files the pull request touched in small deliberate ways, runs the tests that cover them, and reports every change none of them noticed - "these 2 changes to your code would have slipped past your tests", with the lines. Off by default because each change costs a real test run; prove-budget (default 300s) caps the whole thing, and it says which files it did not reach rather than implying they were clean. Every file is put back exactly as it was. Each unnoticed change also enters the attestation as a refusal: a line nothing checks is not a line this bundle can claim was verified.
  • Evidence, every run: the Action writes an attestation into its artifact - the claims with their evidence and which layer decided each, what Tewip refused to decide, and what it did not check at all. Nothing enters it that Tewip did not verify itself, so a release decision can be taken from it without opening CI.
  • Fixes (autofix: true): for drifted locators that the deterministic rule matched to a renamed element, it rewrites the locator, re-runs that test, and opens a separate pull request with the changes that passed. It never merges and never edits application code.
  • Every role: uploads all role views as the tewip-report artifact.
  • When the job dies before any test runs (an image that would not pull, a runner out of disk, a service container that never came up): it reads the failed job's log and names the cause, instead of leaving a red X with no explanation.
  • History: keeps the run history in the Actions cache, never in git.
  • Corrections: reply to the agent's comment with /triage CATEGORY #n reason (e.g. /triage TIMING #2 flaky on CI). It stores that with the history and, next time that test fails the same way, gives the person's answer instead of its own, naming them and their reason. A corrected failure also costs nothing: it never goes to the model again.

For senior engineers, architects and leads, add a scheduled workflow with mode: report, for example weekly. It builds the engineering-quality, architecture and risk-digest views from the stored CI history, reusing earlier diagnoses so it makes no repeat AI calls. The views are kept in one GitHub issue that each report updates:

yaml
on:
  schedule: [{ cron: '0 6 * * 1' }]
  workflow_dispatch:
permissions: { contents: read, issues: write }
jobs:
  report:
    runs-on: ubuntu-latest
    steps:
      - uses: hmamut39/tewip@main
        with: { mode: report }

The report reads the history cache of the branch it runs on, usually the default branch.

The repository needs "Allow GitHub Actions to create and approve pull requests" enabled for fix PRs. Pull requests opened by the workflow token don't trigger CI themselves; the agent verified each change by re-running the test before opening the PR. It was first proved end to end on a private practice repository, which is why there is no link to click here. If this repository is private, other repositories can only use the action when Settings → Actions → Access allows it.

As a Claude Code plugin (no account, no marketplace approval)

bash
claude plugin marketplace add hmamut39/tewip-plugin
claude plugin install tewip@tewip

That is the whole publication process. A marketplace is a .claude-plugin/marketplace.json file in a git repository, so Tewip publishes one at hmamut39/tewip-plugin - nobody has to approve it, and there is nothing to pay for. That repository holds the plugin only: a manifest, three skills and a pointer to the npm package, which is why this one can stay private. The plugin brings Tewip's MCP server and three skills that tell Claude Code when to use it: before claiming a change is done, when a test fails, and when a change touches a migration. It costs about 410 tokens per session until a skill is actually needed.

The MCP server runs from the published package (npx -y tewip-ai@latest mcp), so the plugin stays small and you always get the current version.

The editor extension (VS Code, Cursor, Windsurf, VSCodium)

Open the Extensions pane and search for "Tewip". It is in both registries, so that works in VS Code, Cursor, Windsurf, VSCodium, Gitpod and Eclipse Theia:

Or install the .vsix attached to any release with Extensions: Install from VSIX…. Either way it needs the command line: npm install -g tewip-ai.

Press Ctrl+Shift+P and type "Tewip" for: Is this work done?, Can everybody use this?, Could these tests ever fail?, Would the tests catch a bug in this file?, Which tests could notice this change?, What will this migration do to a live database?, Why did CI fail on this branch?, and more. The editor's AI assistant also picks Tewip up as an MCP server with nothing to configure.

2. From any AI assistant, through MCP (the whole IT team)

mcp/server.ts is a read-only Model Context Protocol server. Anyone on the team can ask their own assistant about test failures, in the editor or chat they already use:

Ask your assistantTool it uses
"Why did CI fail on PR 12 in our-org/web?"github_ci_report: the latest CI report for that PR, plus any verified fix PR
"Explain the failing checkout test"explain_failure: root cause, confidence, evidence, history on this commit vs others, next action
"What should I fix first from the last run?"triage_board (SDET) · pr_impact (developer)
"Is the test environment broken?"environment_report (DevOps / SRE)
"Can we release?"release_readiness (business / UAT)
"Where is our test suite fragile?"quality_report (senior / principal) · architecture_report (architect) · risk_digest (lead)
"Write a test plan for the checkout feature in C:\work\shop"test_plan: risks and scenarios grounded in that project's tests, code and pages; saved in its .tewip folder

Setup, after npm install:

  • Claude Code in this repo: .mcp.json is already here, so approve tewip when asked. From anywhere else, run claude mcp add tewip -- tewip mcp (installed), or claude mcp add tewip -- node /path/to/tewip/mcp/server.ts (from a checkout).
  • Claude Desktop, Cursor, VS Code, and other MCP clients: add a stdio server with command tewip and args ["mcp"], or command node with args ["/path/to/tewip/mcp/server.ts"] from a checkout.

github_ci_report uses the gh CLI login on your machine. The other tools read the datasets under data/, and the AI layer uses OPENAI_API_KEY from .env.

Use it from your editor (any IDE that speaks MCP)

VS Code, Cursor, Windsurf and VSCodium: install the Tewip extension (extensions/vscode, packaged as tewip-<version>.vsix: Extensions → … → Install from VSIX). It registers Tewip as an MCP server by itself, so the assistant can use it with no configuration, and adds two commands: Tewip: Explain a test report… and Tewip: Why did CI fail on this branch?

Every other MCP client (JetBrains IDEs 2025.2+, Claude Code, Claude Desktop, or an editor without the extension) takes one entry. With Tewip installed from its release file (npm install -g tewip-<version>.tgz), the command is simply tewip mcp; from a checkout, point at cli/tewip.ts:

Point the entry at this checkout with an absolute path (the server resolves its own data, so the editor's working directory does not matter). VS Code uses its own shape, with a servers key and a type; put it in the workspace's .vscode/mcp.json, or in your user-level configuration (command MCP: Open User Configuration) to have it in every window:

json
{
  "servers": {
    "tewip": { "type": "stdio", "command": "tewip", "args": ["mcp"] }
  }
}

Cursor, Claude Desktop, Windsurf and most other clients use the mcpServers shape (Cursor: Settings → MCP):

json
{
  "mcpServers": {
    "tewip": { "command": "tewip", "args": ["mcp"] }
  }
}
  • JetBrains (IntelliJ, WebStorm, PyCharm 2025.2+): Settings → Tools → MCP Server.
  • Inside this repository nothing is needed for Claude Code: .mcp.json is already set up.

Then ask, in plain language: "why did CI fail on my PR?", "which tests are flaky in checkout?", "is the main branch safe to release?". You can also ask it to "write a test plan for the checkout feature in C:\work\shop": the test_plan tool plans from that project's real tests, code and pages, and saves the plan in its .tewip folder. Every other tool is read-only, and github_ci_report reads the report the Action uploaded, so you can ask about a repository's CI without cloning it or opening the Actions page (it uses your gh login).

Plan and write tests (Phases 6 and 7, new)

Run these inside your project. Both need OPENAI_API_KEY, and both print what they cost.

bash
tewip plan "Checkout: a signed-in shopper pays by card and gets a receipt" --url http://localhost:3000/checkout
tewip write                        # tests for the plan's "to automate next" scenarios
tewip write --only CO-002,CO-004 --framework pytest
  • tewip plan reads what is really there: the tests you already have (in any language), the change (--diff main...HEAD), the live pages (what a user sees on each page, via Playwright), and the failures Tewip has diagnosed in this project before. The plan lists risks and scenarios by priority. A claim that a scenario is "already covered" is checked against your real test names, and dropped if no such test exists. Saved to .tewip/plans/ as Markdown to review and JSON for write.
  • Does a plan catch real bugs? Measured on 18 real pull requests that were later found to have broken something: the repository is fetched at the pull request's own head, the plan written from the diff a reviewer saw, and nothing about the bug is known to it. In 8 of the 9 pairs that could be judged, a scenario named the bug - in matrix-org/complement, NLnetLabs/domain, Bioconductor/rhdf5, Try/OpenGothic and others. One pull request was titled "Resolve nightly warnings" and the plan still found the behaviour change hidden inside it. The caveats are real and written out in ROADMAP.md: nine judged pairs is a small sample, Claude did the judging rather than each project's engineers, and the one miss is the interesting case - when a pull request's intention is wrong, a plan grounded in that intention agrees with it.
  • tewip write writes each scenario as a test in your framework and style: Playwright, Cypress, WebdriverIO, Angular, Jest, Vitest, pytest (with Selenium or Playwright), JUnit on Maven or Gradle (Selenium, Spring Boot), .NET or Go. It copies the style of an existing test and uses only elements seen on the real page. Front-end apps get component tests the way their own tests are written: React, Vue or Svelte with Testing Library under Jest or Vitest, and Angular through ng test (Karma and Jasmine, or Vitest). A project with both e2e and unit tests gets browser tests when the plan read pages, and unit or component tests when it did not. Then it runs the test. A draft is kept only if it passes every run (3 by default) and fails once its main check is broken on purpose, because a test that cannot fail is worse than no test. A failing draft is repaired from the real error, twice at most. If the test looks right and the app does something else, Tewip reports a possible bug instead of weakening the test until it passes. Kept tests are new files beside yours, for you to review and commit; nothing is committed, and no application code is touched.

Check the page against the design (Phase 11, new)

bash
tewip design "https://www.figma.com/design/KEY/Checkout?node-id=12-34" --url http://localhost:3000/checkout
tewip design frame.json --frame "Sign in"     # a saved frame, no Figma token needed

Tewip reads the frame (Figma's REST API, read only, TEWIP_FIGMA_TOKEN) and the running page (its accessibility snapshot, which is what a screen reader and a test both see), and says where they disagree: the design says button "Sign in", the page says button "Log in". It checks the words the design specifies, the controls its layer names imply, and the regions its sections imply - never pixels, colours or spacing, because a design tool and a browser do not measure those the same way. No model is called, so it costs nothing and answers the same way every time.

Measured on four real design/page pairs (a public repository's Figma exports and the pages built from them): 38 checks, 0 differences reported on pages that match their design, 11 of 11 real drifts caught (a renamed control, a dropped sentence, a word swapped inside a sentence, a region that lost its markup) and 5 of 5 harmless changes ignored (capitals, extra spaces, a button implemented as a link, reordered sections). No designer has judged the output yet, so the roadmap's own metric is still open.

More runners: Robot Framework, JMeter, k6 (new)

Tewip now reads Robot Framework's output.xml, JMeter's .jtl and a k6 summary as well as JUnit XML, TRX, NUnit and Playwright's own reports. A load test does not fail test by test, so a JMeter report becomes one line per request ("4 of 5 requests failed, an assertion failed") and a k6 run becomes one record per crossed threshold, with the number that crossed it.

Appium and Selenium need no importer: those suites report through Mocha, pytest or JUnit, which Tewip already reads, and their own error messages ("Could not find a connected device", "stale element reference") are already understood.

Each reader was checked against real reports published in public repositories, which is how three defects were found before release - a Robot timestamp that is not a date, k6's numbers living under values, and a JMeter line that read "mostly 200" when an assertion had failed.

Tell it when it is wrong (new)

bash
tewip correct diagnosis "checkout charges twice" TEST_DATA "the fixture has stale prices"
tewip correct flaky "adds an item" fix-now "it is a real race, not flakiness"
tewip correct security "src/config.ts:12" noise "that is a sample key in a fixture"
tewip correct --list

Tewip answers with your decision from then on, and says it was yours: "TEST_DATA, confidence 1.00, source: corrected by a person". Corrections live in your project, so they belong to the team; the newest one wins, so changing your mind is just saying so again.

A correction changes what Tewip says, never what it does on its own — it will not change code, quarantine a test or file a ticket because you corrected it.

What your corrections add up to (new)

bash
tewip learn                      # where Tewip is systematically wrong, from what you corrected
tewip learn --labels labels.jsonl  # your corrections as labelled examples, to measure a change against

One correction fixes one failure. Twenty of them say which rule to change. tewip learn groups them - "45x said REAL_BUG, you said TIMING; rule locator-drift decided 27 of them; from 11 different tests" - and points at the rule to read, with three of the real failures underneath.

It will not pretend. Fewer than three corrections of the same shape is "not yet a pattern", not a finding; when no single rule is behind a group it says a rule is missing rather than blaming one; and it tells you how many different tests a pattern came from, because one flaky test corrected six times is one piece of evidence, not six.

Build a feature, test first (new)

bash
tewip build "naturalsize should take a sep argument that goes between the number and the unit"
tewip build --issue PROJ-123    # build from the ticket's own description and acceptance criteria
tewip build "..." --pr          # commit the proved work on its own branch, open a draft PR
tewip build "..." --dry-run     # prove it, show the patch, leave nothing on disk

Tewip writes the test first and runs it. If that test passes, it stops and keeps nothing — a test that passes before the feature exists is testing nothing. Then it writes the smallest code that makes the test pass, and keeps the work only if the new test passes and nothing that was passing has started to fail. Otherwise every file goes back byte for byte, including the test it wrote. Nothing is ever committed.

Tried on two real public projects: it added a trailing-slash rule to unjs/ufo (4 lines, TypeScript, $0.18) and a sep argument to python-humanize (2 lines, Python, $0.10), each with its own failing-then-passing test and the project's whole suite still green. Asked for something that already worked, it stopped after one model call and kept nothing.

It also refuses a feature that does not belong here at all. Handed a real Apache ticket about a Flink HTTP sink, a URL library got an "HTTP sink" built into it - test passing, suite green, every proof rule held, because when Tewip writes both the test and the code it can always make a self-consistent pair pass. So before writing anything it now asks whether the words of the feature mean anything in this repository, and refuses for free when they do not.

The old promise was "it can't touch your code". The new one is "it can't change your code without showing you it works".

Before anyone reads the diff (new)

bash
tewip review --diff main...HEAD

Which tests cover this change and how (they import the file, they import the package that exports it, or their words merely match); which of them have flaked before, so a red run is not blamed on your change; what has gone wrong in these areas before; what nothing tests at all; and the command to run the telling tests first. From your project's own history, so it costs nothing.

Measured on 16 real commits from two public projects, where the developers changed source and its test: given only the source files, Tewip named the right test in 16 of 16, ranked it first in 12.

It also shows the checks a change renegotiates — every test assertion the diff rewrites, withdraws or renames, with the old text beside the new one. A test written earlier is behaviour someone agreed on, and this is the one thing in a review that the change's own description cannot account for: everything else reads the change's account of itself. It never passes judgement — tests change for good reasons — it asks which of them the author intended.

Alongside it, the decisions a change alters outside its tests: a guard that refused something, a value other code falls back on, a limit that decides behaviour under load, a version or runner pinned on purpose. Same rule - only things that already existed, never additions - and the same question rather than a verdict.

Both came out of a measurement rather than an idea. Of 18 real pull requests later found to have broken something, the one Tewip's test plan missed was one whose intention was wrong: it changed a freshness rule, changed the tests to match, and was reverted the next day.

What these checks are not is a predictor, and the measurement says so plainly. On 14 pull requests known to have caused a regression they speak up on 4; on 30 ordinary merged pull requests from the same repositories, on 9 - 29% against 30%. A change that alters an agreement is not more likely to be broken. What they do is put those alterations in front of a person: on the ordinary set they surfaced 23 of them, among which a raise SystemExit guard that was deleted, a semaphore dropped from 4 to 1, and a CI runner image moved. No model is called, so this costs nothing.

Which flaky tests to quarantine, and what they cost (new)

bash
tewip flaky --days 30        # the dossier: quarantine, fix, or watch - with the evidence
tewip flaky --apply          # writes the quarantine line into the test file

Other tools count retries. Tewip already decided why each failure happened, so it can say: this test failed in 161 of 647 runs across 109 different branches - that is the test, not your change - and quarantining it gives the team back 148 CI minutes a week. It refuses to hide a test that mostly fails (that one is broken, not flaky) and never quarantines a test whose failures looked like a real bug.

Measured on three real projects' CI history (Gutenberg twice, Supabase): 76 tests proposed for quarantine, zero of them containing a single real-bug failure, giving back roughly 34, 148 and 1,178 CI minutes a week. It also tells you when a quarantined test has stopped failing and should come back - the half nobody ever does.

Bugs filed back, and test cases where your team keeps them (Phase 10, completed)

bash
tewip bugs report.xml --project SHOP             # shows what it would file; nothing is created
tewip bugs report.xml --project SHOP --create    # files them
tewip jira plan.json --export xray --out cases.csv    # or --export zephyr

tewip bugs files a ticket only for failures it diagnosed as a real bug, with the error, the evidence and the run link. A flaky test or a broken environment is deliberately not filed - that is the point of diagnosing first. The same failure is never filed twice: the second sighting is a short note on the ticket Tewip itself opened. A dry run needs no Jira account at all.

--export xray|zephyr writes the plan's scenarios as the CSV those tools import, one row per step. No account, no network; importing stays your step.

Security: which findings actually matter (Phase 9, new)

bash
tewip secure                              # secrets + npm audit / pip-audit / osv-scanner, triaged
tewip secure --url http://localhost:3000  # also check the running app
tewip secure --zap-report zap.json        # and triage an OWASP ZAP baseline report
tewip secure --gate                       # fails a build only on what needs a person now

Scanners are good at finding things and bad at saying which of them matter. Tewip runs the ones your project already has and sorts every finding into act on this now, real but not reachable (a dev dependency, a package nothing imports, a file git does not track), noise (a placeholder from a README), or accepted (a person already judged it, in a file only people write). Each verdict carries the evidence. No model is called, so it costs nothing, and a credential is located, never printed.

With --url it also checks the running app the way a browser would: security headers, cookie flags, and the files that must never be served (.env, .git). No payloads, no fuzzing, no login bypass - and an address that is not your machine is refused unless you say --i-am-authorised. For the deep scan it prints the OWASP ZAP command and triages ZAP's report rather than pretending to be a scanner.

Measured on the gitleaks project's own labelled samples, for the credential kinds Tewip covers: 50 of 54 real credentials found. The web check found 8 of 8 planted weaknesses in two local apps and reported nothing about the carefully served one; on four real public homepages its report matched the headers those sites actually send, every time. Four defects that corpus exposed are fixed; the four still missed are things that are not credentials (an unsigned token, a Stripe test key). It never claims a project is secure - it prints what it checked and what it did not.

Epics, stories and acceptance criteria (Phase 14, new)

bash
tewip spec "Readers can search the library and open a result"
tewip spec "..." --project PROJ            # shows what it would file in Jira
tewip spec "..." --project PROJ --create   # files the epic and its stories

An epic, user stories and Given / When / Then acceptance criteria, written from your code, your tests and your failure history. Anything it says the system already does carries a quote from a file it read, and Tewip checks that quote word by word; what it cannot quote becomes an open question instead of a confident sentence. It writes no estimates, dates or business cases, because it cannot check them.

Measured on three real projects: 15 stories, 49 acceptance criteria, and of 46 claims about existing behaviour, 22 were kept with a checkable quote and 24 were turned into open questions.

Any CI, your chat, and your own machine (Phase 13, new)

bash
tewip report report.xml --gate      # GitLab CI, Jenkins, CircleCI, Azure, Bitbucket, Travis, Drone
tewip watch --cmd "npm test"        # beside your editor: explains each failure as it happens
tewip note --days 7                 # the weekly quality note for a lead - free, no model calls

tewip report reads which CI it is in from that platform's own variables, prints the triage board, writes it to a file, appends it to the job summary, and with --gate fails the build only on failures that are not known flaky or environment noise. On GitLab it posts the diagnosis as one merge-request note and edits that same note next run instead of piling up. With TEWIP_SLACK_WEBHOOK or TEWIP_TEAMS_WEBHOOK it tells the team's chat - and says nothing at all when no failure needs a person, so nobody mutes it.

Fix the code, but only when the tests prove it (Phase 12, new, opt-in)

bash
tewip fix --code report.xml          # shows the patch; your files are left as they were
tewip fix --code report.xml --apply  # leaves the proved change in your working tree

Tewip has refused to touch application code since day one. This is the one exception, and it only runs when you type --code. It takes a failure it diagnosed as a real bug (0.85 confidence or more), finds the file the failure points at, asks for the smallest change, and then proves it: the failing test must pass and the whole suite must still pass. It will not edit tests, configuration, CI files, lockfiles, migrations or anything with secrets in it, because a test going green after changing those proves nothing. If it cannot prove a change, it explains the bug instead and puts your file back byte for byte. It never commits and never merges.

Measured by replaying 16 real bug fixes from two public repositories, in two languages: the commit before each fix, with only that fix's tests, so the real bug really reproduces.

ProjectLanguageBugsProved by the testsRight file
unjs/ufoTypeScript, Vitest888 of 8
python-humanize/humanizePython, pytest888 of 8

Every change is small (1 to 16 lines, median 4) and most are what the developers themselves wrote. No wrong fix was offered: anything that could not be proved was thrown away and the file put back byte for byte.

One bundle a release manager can read (Phase 15)

bash
tewip attest --out attestation.md

Everything Tewip knows about a build, in one file: which tests ran, what each failure was, which rule or which model decided it, what it refused to decide, and what it never looked at. The refusals are the point - a tool that never says "I could not tell" has nothing worth attesting, because every line it writes might be a guess.

The bundle carries a digest, and an Ed25519 signature when you give it a key:

bash
TEWIP_ATTEST_KEY=./private.pem tewip attest            # sign it
tewip attest --verify attestation.json --key public.pem  # check it

A digest is not a signature and Tewip says so: without a key it tells you the bundle is undamaged, not that nobody edited it. Editing a claim out of a signed bundle makes verification fail and exit non-zero. Every CI run writes one of these automatically.

Is this incident covered by a test? (Phase 16)

bash
tewip incident sentry-issue.json

Reads a Sentry payload, an OpenTelemetry span or a plain stack trace, finds the test that should have caught it, and answers with one of four verdicts: reproduced, passed (the test ran and did not catch it, which is worse news), failed differently, or never ran. It does not say "probably covered".

What did we decide about this last time? (Phase 17)

bash
tewip recall "the login test that keeps flaking"

Every correction your team ever gave Tewip is kept. Ask, and it answers with your own decision from then, and says it was yours - not its. It never acts on a correction by itself.

From the ticket to the run (Phase 18)

bash
tewip trace --only "SHOP-12"

Joins the test plans Tewip wrote to the tests that cover them and the runs that attempted them. A scenario counts as covered only when a real test can be named, and passing only when a real run attempted it; everything else says what is missing. No model, no cost.

Is this work actually done? (Phase 24)

bash
tewip done --diff main...HEAD            # one verdict
tewip done --prove --strict              # also break the code, and fail the build unless ready
tewip done --json done.json              # a sealed verdict that can be checked later

Tewip can answer six questions about a change. A team reviewing an agent's pull request has to run six commands and assemble the answer themselves - which in practice means they run none and merge on a green tick. done is the assembled answer:

# Is this work done? Not ready

| Question                                   | Answer      |
| Is anything failing?                       | not checked |
| Is the changed code tested?                | yes         |
| Can the tests in this change fail?         | no          |
| Would the tests catch a bug in this code?  | no          |
| Is what was asked for covered?             | not checked |

That is a real run on a change where all three tests passed. One of them was assert.ok(true), and three deliberate changes to the new code went unnoticed by the suite. CI was green; the work was not done.

Nothing is judged here. Every answer comes from a layer with its own measured accuracy — the triage rules, vouch, prove, trace — and this only puts them in a fixed, published order: what is broken, then what cannot be believed, then what is missing. The same change always gets the same verdict.

"Cannot say" is a real answer, and it is never rounded up to ready. A verdict needs the two questions nothing can substitute for — is anything failing, and does anything actually test this code — to have been answered. If Tewip has never seen a test result for the project, it says so and refuses to approve; the first version of this answered "Ready, with 3 not checked", which is an approval assembled out of shrugs. Every verdict also ends with what it says nothing about, including the one thing no tool here can know: whether the change does what was intended.

With --json the verdict is sealed: editing not-ready to ready in the file makes verification fail, so a verdict that travels into a ticket or a release note can be checked rather than trusted. It is also an MCP tool, so an agent can ask whether its own work is done before saying that it is.

Tewip as a peer other agents must satisfy (Phase 34, new)

bash
tewip a2a                 # serves on 127.0.0.1:41241

MCP lets an assistant call Tewip as a tool. A2A is the other direction: Tewip as an agent in its own right, which another agent has to get past before its work counts as finished. That is the right shape for a tool whose whole claim is proving work written by a person or by an agent — when most code is written by agents, the thing that checks it has to be reachable by agents.

It serves the card at /.well-known/agent-card.json and answers JSON-RPC SendMessage, with eight skills: triage, vouch, pick, schema, access, perf, standards and done.

It asks rather than guesses. Send "check my code" and you get back a question naming the eight things Tewip answers — A2A has a state for exactly that, TASK_STATE_INPUT_REQUIRED:

TASK_STATE_INPUT_REQUIRED
Tewip will not guess which question you are asking: that could be "Does this keep the
team's own rules?" or "Is this work actually finished?", and Tewip will not pick for you.

The guardrails are the design. This is an HTTP port that runs commands against your repository:

  • Only read-only skills are reachable. fix, write, build, pursue and prove are not on the list — they change files or run your suite. A test asserts they never can be.
  • It listens on this machine alone unless you pass --host, and says plainly what that means.
  • Every request is recorded in .tewip/a2a.jsonl.

Its card declares streaming: false and pushNotifications: false, and those operations return an error naming the field that says why. Declaring a capability you have not implemented is the one thing an agent card must not do.

Is this change slower? (Phase 30, new)

bash
tewip perf summary.json --record            # on main: add this run to the baseline
tewip perf summary.json --strict            # on a branch: fail the build on a real regression

Tewip has imported k6 results for a while and never had an opinion about them. Now it answers the question every team asks before a release.

The hard part is not the arithmetic. "p95 went from 180ms to 210ms, +16%" is four lines of code and worthless, because nobody knows whether 16% is the change or the laptop. Here are four real k6 runs of code that did not change:

run 1   p95 = 60.9ms
run 2   p95 = 60.8ms
run 3   p95 = 62.8ms
run 4   p95 = 61.4ms

A 3% spread from nothing at all. A tool that calls that a regression gets switched off.

So Tewip answers two questions separately, because they fail separately:

Did your own thresholds hold?You already wrote what "fast enough" means in your k6 script. Tewip reads the result instead of asking you to write a budget twice.
Is it slower than it was?Answered only from three or more recorded baselines. Below that: cannot say.

Given those three real baselines, a fourth identical run at 61.4ms is not called a regression — and a genuine one is:

- `http_req_duration` p95 282.5ms — **slower**
  - baseline 60.8ms–62.8ms over 3 runs, middle 60.9ms
  - 282.5ms is outside everything 3 baseline runs produced (60.8-62.8ms) by more than
    their own spread, so the runs cannot explain it. That is +364% on the middle run.

Recording is deliberately not automatic. A tool that files every run into the baseline ratchets: today's regression becomes tomorrow's normal, the comparison keeps saying "within range", and a service triples in latency over a quarter without one report ever being wrong. --record on main, compare everywhere else.

It never predicts a duration, a capacity, or what a user will feel. It cannot see your production hardware, your real data volume or your real traffic, and every report says so.

Lighthouse too (Phase 31, new)

bash
tewip perf lighthouse-report.json --record

k6 measures what your server does under load. Lighthouse measures what one page load costs in a real browser — Largest Contentful Paint, layout shift, blocking time — which is nearer to what a person actually waits for. tewip perf takes either and works out which it was given.

Lighthouse needs the same discipline more, not less. Four real Lighthouse runs of an unchanged page gave LCP of 922, 912, 936 and 916ms. Same rule: three baselines, outside the range by more than its own width.

And Tewip does not invent a verdict. "Is 2112ms bad?" has a published answer and it is Google's: Lighthouse scores every metric on its own curve. Tewip reads that score rather than hard-coding thresholds it remembered — which matters, because on the real slowed run FCP and LCP had the identical value of 2112ms and Lighthouse rates them differently:

- good — `largest-contentful-paint`: 2112ms
- needs improvement — `first-contentful-paint`: 2112ms
- **poor** — `server-response-time`: 611ms

One remembered threshold applied to both would have been wrong.

It also surfaces the ten accessibility audits Lighthouse refuses to score — logical tab order, focus traps, whether visual order follows the DOM. Those are neither failures nor passes, and a page with no failures and ten unanswered manual checks is not a page that passed.

One more thing it refuses: if your summary came from --new-machine-readable-summary, that export records no threshold results at all — the word appears in it only inside a copy of your script. Tewip says "this export cannot tell me" rather than "nothing was breached".

Can everybody use it? (Phase 28, new)

bash
tewip access                           # every markup file in the project
tewip access src/components/Nav.tsx    # or just one
tewip access --strict                  # fails the build on a barrier that stops somebody outright

Reads HTML, JSX, TSX, Vue, Svelte, Astro, ERB, PHP and the server-rendered template languages — Blade, Twig, Jinja, Razor, Handlebars, Liquid, Nunjucks, EJS — which between them are most of the web's actual HTML.

Accessibility is the one quality question that is also a legal one. The European Accessibility Act has been enforceable since June 2025, and it lands on the people who already own testing.

The reason teams do not trust the tools they have is the reason they switch off every scanner: axe, Lighthouse and pa11y hand back several hundred undifferentiated violations, a large share of which are not barriers at all, and nobody has the afternoon it takes to sort them.

Tewip makes two kinds of statement and no third:

  • a barrier — the element as written stops somebody, and reading it is enough to know that;
  • a question — something here is missing or unreadable, and only you can settle it.

There is no "warning", because a warning is the category people learn to scroll past.

**6 barriers (5 that stop somebody outright), 18 for a person to settle.**

### button-name - 3 places

WCAG 2.2 4.1.2 Name, Role, Value (A), blocker.

Who it stops: a screen reader announces "button" and nothing else, so it cannot be used or spoken to.

- `components/VPNavBarAskAiButton.vue:2`  <button type="button" class="VPNavBarAskAiButton">
  - it contains no text and carries no aria-label, so it is announced with its role and nothing else
  - do this: put text inside it, or add aria-label="..." saying what it does

Every finding names its WCAG 2.2 success criterion and level, which is what turns it into something you can put in front of a regulator instead of a note saying "bad contrast".

What it refuses to decide is the reason it is worth running. alt={caption} is not a missing alt. A button whose text comes from a child component cannot be called empty. :aria-label="label" is a label. <slot /> is content this file cannot see. Each of those becomes a question, never an accusation — because a tool that accuses <img alt={alt} /> of having no alt text gets switched off in a day.

And every report prints what it did not check — contrast, focus order, meaningful sequence, whether the alt text is any good — because those need a rendered page. A clean result means these checks found nothing. It never means the product is accessible.

No browser, no server, no network, no model, no cost. 416 real files in 1.65 seconds.

Measured on four public projects, never on fixtures — excalidraw, bootstrap, vitepress and svelte: 50 barriers, 29 of them the kind that stop somebody outright, and 90 questions. Seven false-positive classes were found and fixed along the way, every one of them a defect in Tewip rather than in the projects, and none of them reachable from a fixture. They are listed in ROADMAP.md.

Already run axe? Give Tewip the JSON (Phase 29, new)

bash
tewip access --report axe-results.json

Reading markup cannot see contrast. A browser can, so if your Playwright, Cypress or jest-axe suite already writes an axe report, hand it over — and Tewip will triage it instead of relaying it.

This is where the numbers get uncomfortable. axe 4.14 over nine real pages returned 174 findings:

53 barriersa real WCAG criterion, with the EN 301 549 clause the EU Accessibility Act cites
51 adviceaxe rules tagged best-practice that map to no criterion at all
70 questionsaxe's own incomplete — it could not determine them

42% of what axe hands you tests no standard. region alone — "all content should be contained by landmarks" — was 40 findings, outnumbering every real barrier on the page. Tewip reports those as advice, never as barriers, and they never fail a build. That separation is most of the point.

And the unchecked list shrinks, honestly: one of its seven entries — 1.4.3 Contrast — moves to checked. The other six stay, because no tool settles them. The report also names how many pages the run covered, and says plainly that nothing is known about a page it did not open or a state it did not reach.

## Checked here only because a browser run was given

- **1.4.3 Contrast (Minimum)** - would otherwise be unreachable: needs the computed colours of a
  rendered page, not the markup

A source finding is set aside only when the run opened that same file and re-ran the equivalent rule. In a React or Vue project that means nothing is set aside — the source and the rendered output are two different artefacts, and neither is evidence about the other.

Already run Lighthouse instead? That works too (Phase 32, new):

bash
tewip access --report lighthouse-report.json

Lighthouse's accessibility audits are axe rules — same rule ids — so the same triage applies. Most teams have Lighthouse in CI and no separate axe step; they get the whole of the above from a tool they already run.

The catch was that a Lighthouse report strips axe's tags, so it says landmark-one-main and nothing about which WCAG criterion that is, or whether it is one at all. That distinction covers 30 of axe's 105 rules, and a remembered table of a hundred mappings is a table with mistakes in it. So the table is generated from axe-core itself (scripts/axe-rules.ts) — 105 rules, 75 carrying a criterion, 30 best-practice only, none unclassified.

It also surfaces the ten audits Lighthouse marks manual — logical tab order, focus traps, whether visual order follows the DOM. Those become questions, never passes. A page with no failures and ten unanswered manual checks has not passed.

Teach it your house rules (Phase 27)

bash
tewip standards                        # what this project has taught Tewip
tewip standards --diff main...HEAD --strict

Tewip knows a lot that is true of software in general and nothing that is true of your company. Every IT department has its own rules — "never drop a column in the release that stops writing to it", "locators use data-testid", "no test may sleep" — and a tool that cannot be taught them is a tool that argues with the house.

A standard is a markdown file in .tewip/standards/:

markdown
---
description: A fixed wait hides a race instead of fixing it.
applies-to: tests/, e2e/
forbid: /waitForTimeout|sleep\(/ because a fixed wait passes by luck and fails in CI
---

Wait for the thing you are actually waiting for — an element, a response, a state —
never for a number of milliseconds.

The split is the point. The forbid and require lines are checked and enforced, with the offending line quoted and your own reason printed beside it. The prose below is guidance: Tewip carries it into whatever it writes or fixes, and quotes it in reports — but it is never counted as checked and never reported as kept. A team that believes an unenforceable rule is being enforced is worse off than a team with no tool at all, because they have stopped watching for it themselves. A rule Tewip cannot parse is reported as unusable rather than silently dropped.

Once written, the rules appear everywhere the work is judged: in tewip review, in the pull request comment, and as a question in tewip done — "Does it keep this project's own standards?" — which answers no and names the rule. The guidance goes into the prompt when tewip write drafts a test, so what comes back is in your conventions rather than Tewip's.

What will this migration do to a live database? (Phase 26)

bash
tewip schema --diff main...HEAD      # or: tewip schema migrations/0002_drop_nickname.sql
tewip schema --strict                # fails the build on a change that breaks the running version

The most expensive change in a pull request is usually not a test — it is a migration. A column dropped while the previous deployment is still selecting it. An index built without CONCURRENTLY, blocking every write to the busiest table. A NOT NULL added to a populated table. These are known, documented, and a tool can name every one of them from the text of the migration.

1 of 1 migration file(s) read. 1 change(s) would break the running version or destroy data

## Breaks the version that is still running (1)
- drops the column nickname from orders — migrations/0002_drop_nickname.sql:1
  - Instead: deploy code that no longer selects or writes the column, then drop it in a later
    migration. During a rolling deploy the old version is still running and will fail on a column
    that is gone

## Code that still uses what this takes away (1)
- orders.nickname is still named in 1 file(s): app/orders.py

That last section is the part no SQL linter does: it searches your own code for what the migration takes away. "This drops users.nickname, and four files still read it" is a different sentence from "dropping a column is risky", and it is the one that stops the outage.

It reads SQL, Django, Rails, Alembic, TypeORM, Sequelize, Knex, Laravel, EF Core and Liquibase migrations — which covers Prisma, Drizzle, Flyway and golang-migrate too, since those all emit plain .sql. It judges only the forward path (a rollback step contains the mirror image of the change, so reading it says a migration that creates a table destroys one), and stays quiet when the team already did the safe thing — atomic = False, algorithm: :concurrently, NOT VALID, postgresql_concurrently=True. When it cannot read a migration it says so rather than passing it, and "read and nothing found" never looks like "not read".

Tried on real projects. 200 Zulip migrations: 199 read, 19 changes that break the running version or destroy data, each sampled finding correct when read against the file — including a DROP COLUMN buried in raw SQL inside a Python data migration. 60 Mastodon migrations: it caught a change_column that rewrites a table, in a migration whose name says it only adds one.

What it does not know, and says so: your table sizes and how busy the database is, so it reports what a statement does — rewrites the table, scans every row, blocks writes — and leaves the duration to the person who knows the data. In CI the findings go into the pull request comment, and anything that breaks the running version enters the evidence bundle as a refusal: a passing test suite does not verify a migration.

Run only the tests that could notice this change (Phase 25)

bash
tewip pick --diff main...HEAD     # or: tewip pick src/pricing.js
tewip pick --list                 # just the files, for piping into your runner

A forty-minute suite is a suite people stop running. Vendors sell this as a prediction - a model guesses which tests matter - and a guess is the wrong shape for the job, because the cost of being wrong is a bug reaching production and nobody can audit a guess.

Here, skipping a test is a claim that it could not have noticed the change, and a claim needs evidence. A test runs when it imports a changed file, reaches one through another module, is edited by the change itself, reads the repository at run time (a guard that scans every source file can be broken by any file), or has failed recently — an unknown is never a skip. Everything else is left out with the reason printed beside it.

It refuses to narrow at all when the change touches dependencies, build or test configuration, shared setup or fixtures; when the suite drives a browser, because what a browser test exercises is not written in its imports; or when a changed file cannot be traced to any test, since code is reachable in ways an import does not show.

Measured by breaking the code (eval/pick-safety.ts): make a real mutation, ask pick what could notice it, then run the whole suite to find out which tests really catch it. A failure is dropping a catching test.

ProjectJudged casesCatching test lostSuite selected
This repository (node --test, 76 test files)807–9%
expressjs/express (Mocha, 88 test files)20refused to narrow — every test reaches the change

Those two rows are the point. On a layered codebase it runs under a tenth of the suite and keeps every test that would have caught the bug; on a monolith where every test imports the package front door it says there is nothing to skip, rather than inventing a saving. It is also an MCP tool, so an agent can ask what to run before running anything.

In CI, mode: pick runs before your tests and hands the workflow the files to run:

yaml
- id: pick
  uses: hmamut39/tewip@main
  with: { mode: pick }        # needs fetch-depth: 0 on actions/checkout
- run: npx jest ${{ steps.pick.outputs.tests }}
  if: steps.pick.outputs.narrowed == 'true'
- run: npx jest
  if: steps.pick.outputs.narrowed != 'true'

Whatever it leaves out is written into the job summary with the reason beside it, so "why did CI not run that test" is answered by the run itself. When it will not narrow safely, narrowed is false and tests is empty - so a workflow that ignores the flag still runs everything, which is the safe default.

Would your tests catch a bug? (Phase 23)

bash
tewip prove src/pricing.js              # or --diff main...HEAD for what a change touched
tewip prove src/pricing.js --strict     # exits non-zero when something goes unnoticed

Coverage says a line ran. It does not say anybody checked it. prove settles that by execution: it breaks your code in small, deliberate ways - a boundary moved by one, a condition inverted, an and that became an or, a returned flag flipped, a pattern loosened - runs the tests that reach that file, and reports every change none of them noticed.

4 change(s) were made to your code and the covering tests were run against each. 3 went unnoticed.

- line 2: a boundary moved by one
  - was:    if (total >= 100 && isMember) return 0.2;
  - became: if (total > 100 && isMember) return 0.2;
- line 9: a sign reversed
  - was:    return total - total * off;
  - became: return total + total * off;

Both of those are real: the tests used 150 and 10 and never the boundary itself, and the test calling finalPrice asserted nothing at all. Neither gap is visible in a coverage report, because both lines were covered.

It refuses more often than it reports, and the refusals are the reason the reports are worth reading:

  • Your file is put back exactly as it was, byte for byte, line endings included, in a finally - and the restore is verified, not assumed. A restore that did not work is an error, not a shrug.
  • Nothing that can hang is touched. Loop headers are never changed: a flipped comparison in a while does not fail a test, it runs forever.
  • A red suite proves nothing. Every covering test is run untouched first. Ones that do not pass are set aside by name, and if none pass, it says so and stops - a test that was already failing would otherwise appear to "catch" every change.
  • It checks that your tests actually load the file. If breaking the file outright does not fail a single test, they are reading an installed copy or a build output, and it says that instead of reporting a page of holes that do not exist. This caught a real case on the first Python project it met, where import humanize resolved to a different checkout entirely.
  • Strings and comments are never changed, because changing a message is not a bug a test should be expected to catch.

It follows imports, so a file reached through another module is still proved - in a layered codebase that is most of them. It needs a unit test framework (jest, vitest, mocha, node --test, pytest, go test, maven, gradle, dotnet), calls no model, and costs nothing but time. It is also an MCP tool, so a coding agent can ask whether the tests it is relying on would have stopped its own mistake.

Could these tests ever fail? (Phase 22)

bash
tewip vouch tests/            # or a file, or the whole project
tewip vouch tests/ --strict   # exits non-zero, for a merge gate

Reads JavaScript, TypeScript, Python, Java, Kotlin, Scala, Go, C#, Ruby, PHP and Rust — and says so, rather than clearing a file it cannot read.

Most tests in a pull request are now written by an agent, and the question that decides whether they are worth anything goes unasked: could this test ever fail? Coverage counts a test that checks nothing. CI goes green on it. A reviewer skims something plausible and approves it.

vouch reads tests somebody else wrote and answers per test, quoting the line it rests on. It finds tests that leave an expectation unfinished (expect(value); with no matcher - it reads exactly like a check), tests that compare a value with itself, tests that catch and discard their own failure, tests that never run, and tests that compare no value at all. No model, no cost.

It is also an MCP tool, so a coding agent can ask about the tests it just wrote before claiming a change is covered.

Measured on 5,448 tests in 8 public projects across 5 languages (express, axios, chalk, requests, click, gorilla/mux, cobra, gson): 19 tests were called unable to fail, and all 19 were correct when read against the files - one unconditional skip in psf/requests, eighteen @Ignore methods in gson.

Two things it refuses to do, which is why the list is worth reading:

  • It will not guess. A test whose checking happens inside a helper it cannot follow is reported as undecided, by name, never as worthless. A wrong accusation about somebody's test costs more than a missed one.
  • It will not overclaim. A test with no assertion still fails when the code throws - in axios, a test that compiles a TypeScript fixture and runs it asserts nothing on purpose. Those are reported separately as "compares no value", not as broken, and they do not trip --strict.

Recall, measured by execution (eval/vouch-recall.ts): mutate a source file, record which tests catch which mutation, remove the last statement of the ones that provably caught something, and run it all again. A test that caught a mutation before and catches nothing now has provably lost its check - a label that owes nothing to vouch's own patterns. On 17 such cases across seven source/test pairs in two projects, vouch named 12 (70.6%), and the five it did not name still hold a real assertion, so it is right about those too. Nothing that still caught a mutation was wrongly accused.

A goal instead of a verb (Phases 19 and 21)

bash
tewip pursue "keep the checkout flow green"
tewip pursue "keep the checkout flow green" --act

Give Tewip a goal and it says what it would do next, and why, from what it can actually see. The order is fixed, published and testable - not chosen by a model: a real bug first, then the environment, then flakiness, then anything failing it cannot explain, then a test that cannot fail, then a coverage gap, and only then is the goal worth attesting. Deciding the same state twice gives the same answer.

With --act it car

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