# Unsupported function: Headers

**URL:** <https://community.traefik.io/t/unsupported-function-headers/17422>\
**Category:** Traefik v3 (latest)\
**Tags:** docker\
**Created:** [February 5, 2023, 9:20pm UTC](https://community.traefik.io/t/unsupported-function-headers/17422 "2023-02-05T21:20:47Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![devinrsmith](https://sea2.discourse-cdn.com/flex020/user_avatar/community.traefik.io/devinrsmith/32/6609_2.png) [@devinrsmith](https://community.traefik.io/u/devinrsmith)\
**Post date:** [February 5, 2023, 9:20pm UTC](https://community.traefik.io/t/unsupported-function-headers/17422/1 "2023-02-05T21:20:47Z")

</div>

The `Headers` function doesn't seem to work in v3.

```auto
2023-02-05T21:05:10Z ERR error="error while parsing rule Path(`/ide`) && Headers(`MyCustomHeader`, `yoyo`): unsupported function: Headers" entryPointName=web-secure routerName=yoyo@docker
2023-02-05T21:05:10Z ERR error="invalid rule Path(`/ide`) && Headers(`MyCustomHeader`, `yoyo`), error: unsupported function: Headers" entryPointName=web-secure routerName=yoyo@docker

```

```auto
      - 'traefik.http.routers.yoyo.rule=Path(`/ide`) && Headers(`MyCustomHeader`, `yoyo`)'

```

If I run without the `Headers` rule, it "works":

```auto
      - 'traefik.http.routers.yoyo.rule=Path(`/ide`)'

```

This is on version v3.0.0-beta2.

---

<div class="post-metadata">

**Author:** ![ldez](https://sea2.discourse-cdn.com/flex020/user_avatar/community.traefik.io/ldez/32/5_2.png) [@ldez](https://community.traefik.io/u/ldez)\
**Post date:** [February 6, 2023, 9:37am UTC](https://community.traefik.io/t/unsupported-function-headers/17422/2 "2023-02-06T09:37:21Z")

</div>

Hello,

take a look at the migration guide: [Traefik V3 Migration Documentation | Traefik | v3.0](https://doc.traefik.io/traefik/v3.0/migration/v2-to-v3/#matchers)

---

<div class="post-metadata">

**Author:** ![devinrsmith](https://sea2.discourse-cdn.com/flex020/user_avatar/community.traefik.io/devinrsmith/32/6609_2.png) [@devinrsmith](https://community.traefik.io/u/devinrsmith)\
**Post date:** [February 6, 2023, 11:49pm UTC](https://community.traefik.io/t/unsupported-function-headers/17422/3 "2023-02-06T23:49:23Z")

</div>

Thanks. Is there a way to choose v2 or v3 documentation?

---

<div class="post-metadata">

**Author:** ![ldez](https://sea2.discourse-cdn.com/flex020/user_avatar/community.traefik.io/ldez/32/5_2.png) [@ldez](https://community.traefik.io/u/ldez)\
**Post date:** [February 6, 2023, 11:59pm UTC](https://community.traefik.io/t/unsupported-function-headers/17422/4 "2023-02-06T23:59:12Z")

</div>

yes at the bottom of the menu

 ![Screenshot 2023-02-07 at 00-57-43 Traefik Proxy Documentation - Traefik](https://us1.discourse-cdn.com/flex020/uploads/containo/original/2X/b/b6aaa2c2b9f21381e1924375dca879279573245f.png)

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex020/uploads/containo/original/2X/b/bd81ebdb578656e76e56ff3cc3eed021d3ba132d.png) [@system](https://community.traefik.io/u/system)\
**Post date:** [February 9, 2023, 11:59pm UTC](https://community.traefik.io/t/unsupported-function-headers/17422/5 "2023-02-09T23:59:25Z")

</div>

Closed on February 9, 2023, 11:59pm UTC

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