Merge duplicate coprocessor documentation

[Copilot]

---

Description

Duplicate coprocessor documentation existed where only one file was linked in the sidebar:

• Live: docs/source/routing/customization/coprocessor/index.mdx (in sidebar)
• Orphaned: docs/source/routing/customization/coprocessor.mdx (not in sidebar)

The orphaned file contained a unique "Per-stage coprocessor URLs" section showing how to override the global coprocessor URL per-stage.

Changes

• Migrated "Per-stage coprocessor URLs" section to live documentation after "Minimal configuration" section
• Deleted orphaned coprocessor.mdx file
• Verified no references to deleted file exist in codebase

# Now documented in the live file:
coprocessor:
  url: http://127.0.0.1:3000
  supergraph:
    request:
      url: http://127.0.0.1:3001  # per-stage override

Checklist

Complete the checklist (and note appropriate exceptions) before the PR is marked ready-for-review.

• PR description explains the motivation for the change and relevant context for reviewing
• PR description links appropriate GitHub/Jira tickets (creating when necessary)
• Changeset is included for user-facing changes
• Changes are compatible¹
• Documentation² completed
• Performance impact assessed and acceptable
• Metrics and logs are added³ and documented
• Tests added and passing⁴
  • Unit tests
  • Integration tests
  • Manual tests, as necessary

Exceptions

• No changeset needed: documentation-only change with no user-facing functionality changes
• No tests needed: consolidated existing documentation content
• No metrics/logs: documentation-only change

Notes

Original prompt

Merge Duplicate Coprocessor Documentation

Problem

We have duplicate coprocessor documentation files where only one is linked in the sidebar:

• Live (in sidebar): docs/source/routing/customization/coprocessor/index.mdx
• Orphaned (not in sidebar): docs/source/routing/customization/coprocessor.mdx

This means content updates might be going to the orphaned file that users never see.

Solution

1. Preserve unique content: Migrate the "Per-stage coprocessor URLs" section from the orphaned file to the live documentation
2. Delete the orphaned file: Remove docs/source/routing/customization/coprocessor.mdx

Specific Changes Needed

1. Add Missing "Per-stage coprocessor URLs" Section

Add this section to docs/source/routing/customization/coprocessor/index.mdx after the "Minimal configuration" section (around line 98):

### Per-stage coprocessor URLs

Override the global coprocessor URL on a per-stage basis:

```yaml title="router.yaml"
coprocessor:
  url: http://127.0.0.1:3000 # mandatory URL which is the address of the coprocessor
  router:
    request:
      headers: false
  supergraph:
    request:
      url: http://127.0.0.1:3001 # overrides the top level URL for supergraph request
      headers: true
      body: true
    response: # uses the top level coprocessor URL for supergraph response
      headers: true
      body: true

This enables targeted coprocessors for individual stages.

### 2. Delete the Orphaned File
Remove the file: `docs/source/routing/customization/coprocessor.mdx`

## Verification
- Ensure the live documentation in `docs/source/routing/customization/coprocessor/index.mdx` has all valuable content
- Confirm the sidebar configuration in `docs/source/_sidebar.yaml` correctly points to the `/coprocessor/index.mdx` file (it already does)
- Check that no other files reference the orphaned `coprocessor.mdx` file

This pull request was created from Copilot chat.

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Footnotes

1. It may be appropriate to bring upcoming changes to the attention of other (impacted) groups. Please endeavour to do this before seeking PR approval. The mechanism for doing this will vary considerably, so use your judgement as to how and when to do this. ↩

2. Configuration is an important part of many changes. Where applicable please try to document configuration examples. ↩

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4. Tick whichever testing boxes are applicable. If you are adding Manual Tests, please document the manual testing (extensively) in the Exceptions. ↩

[apollo-cla]

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[apollo-librarian]

✅ Docs preview ready

The preview is ready to be viewed. View the preview

File Changes

0 new, 3 changed, 1 removed

* graphos/routing/(latest)/customization/coprocessor/index.mdx
* graphos/routing/(latest)/observability/router-telemetry-otel/apm-guides/datadog/router-instrumentation.mdx
* graphos/routing/(latest)/observability/router-telemetry-otel/enabling-telemetry/standard-instruments.mdx
- graphos/routing/(latest)/customization/coprocessor.mdx

Build ID: 447bb25237479d60744560e0
Build Logs: View logs

URL: https://www.apollographql.com/docs/deploy-preview/447bb25237479d60744560e0

[abernix]

Linking this to #8384 where things ended up in the wrong place.

[github-actions]

@Copilot, please consider creating a changeset entry in /.changesets/. These instructions describe the process and tooling.

[pragl]

A couple minor recommendations from our AI reviewer based on the style guide, which I copied in as suggestions. Otherwise, LGTM!

[abernix]

@mergify backport main

[mergify]

backport main

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