diff --git a/docs/contribute/repos/doc-detective.md b/docs/contribute/repos/doc-detective.md
index 870abf92..0fc9d206 100644
--- a/docs/contribute/repos/doc-detective.md
+++ b/docs/contribute/repos/doc-detective.md
@@ -8,4 +8,5 @@ The most common entrypoint for most users, [`doc-detective`](https://github.com/
 
 This repo depends on
 - [`doc-detective-core`](doc-detective-core) for the primary testing logic.
-- [`doc-detective-common`](doc-detective-common) for JSON schema definitions, schema validation logic, and path resolution logic.
\ No newline at end of file
+- [`doc-detective-common`](doc-detective-common) for JSON schema definitions, schema validation logic, and path resolution logic.
+- [`doc-detective-resolver`](resolver) for detecting and resolving documentation into Doc Detective tests.
\ No newline at end of file
diff --git a/docs/contribute/repos/resolver.md b/docs/contribute/repos/resolver.md
new file mode 100644
index 00000000..fea4e46a
--- /dev/null
+++ b/docs/contribute/repos/resolver.md
@@ -0,0 +1,95 @@
+---
+sidebar_position: 4
+---
+
+# `doc-detective-resolver`
+
+[`doc-detective-resolver`](https://github.com/doc-detective/resolver) is an NPM package that detects and resolves documentation into Doc Detective tests. It's installable via NPM (`npm i doc-detective-resolver`).
+
+This repo depends on [`doc-detective-common`](doc-detective-common) for JSON schema definitions, schema validation logic, and path resolution logic.
+
+## Contributing code
+
+Code contributions to `doc-detective-resolver` need tests that maintain code coverage. This keeps the resolver stable across the Doc Detective ecosystem.
+
+### Test requirements
+
+Your contribution needs:
+
+- **Unit tests**: Each source file in `src/` needs a corresponding test file (also in `src/`)
+- **Minimum coverage**: All metrics must meet or exceed baseline thresholds
+- **Coverage ratchet**: Coverage can't decrease from current baselines
+
+Test file locations:
+
+| Source file | Test file |
+|-------------|-----------|
+| `src/openapi.js` | `src/openapi.test.js` |
+| `src/arazzo.js` | `src/arazzo.test.js` |
+| `src/resolve.js` | `src/resolve.test.js` |
+| `src/sanitize.js` | `src/sanitize.test.js` |
+| `src/utils.js` | `src/utils.test.js` |
+| `src/config.js` | `src/config.test.js` |
+| `src/heretto.js` | `src/heretto.test.js` |
+| `src/telem.js` | `src/telem.test.js` |
+
+### Running tests
+
+Run the full test suite:
+
+```bash
+npm test
+```
+
+Run tests with coverage reporting:
+
+```bash
+npm run test:coverage
+```
+
+Verify coverage hasn't decreased:
+
+```bash
+npm run coverage:ratchet
+```
+
+Run all tests including integration tests:
+
+```bash
+npm run test:all
+```
+
+Run all tests with coverage:
+
+```bash
+npm run test:all:coverage
+```
+
+### How coverage is enforced
+
+The coverage ratchet check runs automatically in CI. It compares your coverage against baseline thresholds in `coverage-thresholds.json`. If coverage decreases, the build fails.
+
+Current thresholds:
+
+| Metric | Threshold |
+|--------|-----------|
+| Lines | 87% |
+| Statements | 87% |
+| Functions | 97% |
+| Branches | 84% |
+
+To pass the ratchet check:
+
+1. Write tests for all new code
+2. Run `npm run coverage:ratchet` locally
+3. If the check fails, add tests until coverage is restored
+4. Commit your tests with your code changes
+
+### Test-driven development
+
+TDD works well here. It helps you catch edge cases early and maintain coverage naturally:
+
+1. Write tests that describe expected behavior (tests should fail)
+2. Implement the code to make tests pass
+3. Refactor while keeping tests passing
+4. Verify coverage with `npm run coverage:ratchet`