# Channel profiles

Define destination requirements and review changes without rewriting existing publications.

URL: /docs/channels

A channel describes what a destination accepts. Its publisher connection is a
separate responsibility: a valid content profile does not establish connection
readiness or delivery success. Manual channels need no publisher.

## Edit represented requirements [#edit-represented-requirements]

Use Channels to create or edit a destination. Built-in providers own their native
constraints. Custom content forms expose supported text, title and attachment
controls, with a local composer preview. The preview sends nothing and does not
change existing publication content.

Read required/optional states, units and limit explanations before saving. An
absent title is different from an empty required title. A count shown without a
known maximum is not a promise of unlimited provider content.

A form represents part of a profile; it is not an arbitrary schema editor.
Preserved/read-only controls and validation explain requirements the current
form cannot safely change. Do not assume a successful save converted or removed
unrepresented rules. Server validation remains authoritative.

## Review, assess and activate [#review-assess-and-activate]

For an existing channel, save a draft and review the changes against the active
profile. Run the impact assessment before activation. Editing the proposal can
invalidate an earlier assessment; reread affected publications and current
validation results. Activation does not silently rewrite immutable execution
targets. Adopting a changed profile in a publication remains an explicit action.

A failed refresh after a successful activation does not prove activation failed.
Inspect the current active version before submitting another change.

## Custom HTTP destinations [#custom-http-destinations]

Content rules, request mapping and connection authentication are distinct.
Structured request controls appear for supported mapped contracts. Preserve
locked dynamic/secret fields and examine the active/proposed comparison; the
presence of a form does not mean every expression is represented.

Connection credentials belong to the connection, not to profile JSON. Enter them
through the connection UI and keep them out of logs/examples. A local preview or
schema validation makes no test request and does not prove that an external
endpoint accepts the mapping. An actual delivery has external effects and needs
the same intentional scheduling and outcome review as another automatic channel.