diff --git a/CONTRIBUTE.md b/CONTRIBUTE.md
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--- /dev/null
+++ b/CONTRIBUTE.md
@@ -0,0 +1,18 @@
+![Mizu: The API Traffic Viewer for Kubernetes](assets/mizu-logo.svg)
+# CONTRIBUTE
+We welcome code contributions from the community.
+Please read and follow the guidelines below.
+
+## Communication
+* Before starting work on a major feature, please reach out to us via [GitHub](https://github.com/up9inc/mizu), [Slack](https://join.slack.com/share/zt-u6bbs3pg-X1zhQOXOH0yEoqILgH~csw), [email](mailto:mizu@up9.com), etc. We will make sure no one else is already working on it. A _major feature_ is defined as any change that is > 100 LOC altered (not including tests), or changes any user-facing behavior
+* Small patches and bug fixes don't need prior communication.
+
+## Contribution requirements
+* Code style - most of the code is written in Go, please follow [these guidelines](https://golang.org/doc/effective_go)
+* Go-tools compatible (`go get`, `go test`, etc)
+* Unit-test coverage can’t go down ..
+* Code must be usefully commented. Not only for developers on the project, but also for external users of these packages
+* When reviewing PRs, you are encouraged to use Golang's [code review comments page](https://github.com/golang/go/wiki/CodeReviewComments)
+
+
+
diff --git a/README.md b/README.md
index 088df71af..e540401a4 100644
--- a/README.md
+++ b/README.md
@@ -116,7 +116,8 @@ To generate a new config file with default values use `mizu config -r`
 
 ### Telemetry
 
-By default, mizu reports usage telemetry. It can be disabled by adding a line of telemetry: false in the ${HOME}/.mizu/config.yaml file
+By default, mizu reports usage telemetry. It can be disabled by adding a line of `telemetry: false` in the `${HOME}/.mizu/config.yaml` file
+
 
 ## Advanced Usage
 
@@ -135,14 +136,22 @@ Setting `mizu-resources-namespace=mizu` resets Mizu to its default behavior
 
 ### User agent filtering
 
-User-agent filtering (like health checks) - can be configured:
+User-agent filtering (like health checks) - can be configured using command-line options:
 
-Any request that contains one of those values in the user-agent header will not be captured
-
-```bash
+```shell
 $ mizu tap "^ca.*" --set ignored-user-agents=kube-probe --set ignored-user-agents=prometheus
 +carts-66c77f5fbb-fq65r
 +catalogue-5f4cb7cf5-7zrmn
 Web interface is now available at http://localhost:8899
 ^C
-```
\ No newline at end of file
+
+```
+Any request that contains `User-Agent` header with one of the specified values (`kube-probe` or `prometheus`) will not be captured
+
+### API Rules validation
+
+This feature allows you to define set of simple rules, and test the API against them.
+Such validation may test response for specific JSON fields, headers, etc.
+
+Please see [API RULES](docs/POLICY_RULES.md) page for more details and syntax.
+
diff --git a/TESTING.md b/TESTING.md
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+![Mizu: The API Traffic Viewer for Kubernetes](assets/mizu-logo.svg)
+# TESTING
+Testing guidelines for Mizu project 
+
+## Unit-tests
+* TBD 
+* TBD
+* TBD
+
+
+
+## System tests
+* TBD 
+* TBD
+* TBD
diff --git a/assets/validation-example1.png b/assets/validation-example1.png
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diff --git a/docs/POLICY_RULES.md b/docs/POLICY_RULES.md
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@@ -0,0 +1,78 @@
+
+# API rules validation
+
+This feature allows you to define set of simple rules, and test the API against them.
+Such validation may test response for specific JSON fields, headers, etc.
+
+## Examples
+
+
+Example 1: HTTP request (REST API call) that didn’t pass validation is highlighted in red
+
+![Simple UI](../assets/validation-example1.png)
+
+- - -
+
+
+Example 2: Details pane shows the validation rule details and whether it passed or failed
+
+![Simple UI](../assets/validation-example2.png)
+
+
+## How to use
+To use this feature - create simple rules file (see details below) and pass this file as parameter to `mizu tap` command. For example, if rules are stored in file named `rules.yaml` — run the following command:
+
+
+```shell
+mizu tap --test-rules rules.yaml PODNAME
+```
+
+
+
+## Rules file structure
+
+The structure of the test-rules-file is:
+
+* `name`: string, name of the rule
+* `type`: string, type of the rule, must be `json` or `header` or `latency`
+* `key`: string, [jsonpath](https://code.google.com/archive/p/jsonpath/wikis/Javascript.wiki) used only in `json` or `header` type
+* `value`: string, [regex](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions) used only in `json` or `header` type
+* `service`: string, [regex](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions) service name to filter
+* `path`: string, [regex](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions) URL path to filter
+* `latency`: integer, time in ms of the expected latency.
+
+
+### For example:
+
+```yaml
+rules:
+- name: holy-in-name-property
+  type: json
+  key: "$.name"
+  value: "Holy"
+  service: "catalogue.*"
+  path: "catalogue.*"
+- name: content-length-header
+  type: header
+  key: "Content-Le.*"
+  value: "(\\d+(?:\\.\\d+)?)"
+- name: latency-test
+  type: latency
+  latency: 1
+  service: "carts.*"
+```
+
+### Explanation:
+
+* First rule `holy-in-name-property`:
+
+  > This rule will be applied to all request made to `catalogue.*` services with `catalogue.*` on the URL path with a json response containing a `$.name` field. If the value of `$.name` is `Holy` than is marked as success, marked as failure otherwise.
+
+* Second rule `content-length-header`:
+
+  > This rule will be applied to all request that has `Content-Le.*` on header. If the value of `Content-Le.*` is `(\\d+(?:\\.\\d+)?)` (number), will be marked as success, marked as failure otherwise.
+
+* Third rule `latency-test`:
+
+  > This rule will be applied to all request made to `carts.*` services. If the latency of the response is greater than `1` will be marked as failure, marked as success otherwise.
+