> ## Documentation Index > Fetch the complete documentation index at: https://docs.prelude.so/llms.txt > Use this file to discover all available pages before exploring further. # Replace a rule > **Beta.** The request and response shapes may still change. Overwrite a rule in place. The body is the whole rule, not a patch: what you omit is cleared. The new expression is compiled before it is stored. It is not re-checked against the recipes already scoring over this rule, so an edit that drops an attribute or parameter reference is accepted here and the rule is reported as unavailable at evaluation time. Re-save the recipe to validate the association. The body is the whole rule, not a patch. Both `name` and `expression` are required, and the stored rule becomes exactly what you send. The identifier does not change, so every recipe already scoring over this rule picks up the new condition on its next evaluation. There is no versioning at the rule level. ## Editing a rule a recipe depends on The new expression is compiled against the latest catalog, on its own - not against the recipes that score over it. An edit that starts reading `attr.cart_total` is accepted here even if no recipe declares that key. At evaluation time such a rule can't compile in that recipe's environment. It reports `unavailable` and contributes nothing, and the recipe reports `partial_evidence`. Re-saving the recipe is what checks the pair, and it is the fastest way to confirm an edit landed cleanly. Aiming a replace at a managed rule's identifier answers `403` - `managed_rule_read_only`. ## OpenAPI ````yaml put /v2/watch/management/rules/{rule_id} openapi: 3.1.0 info: title: Prelude API version: 2.0.0 description: The Prelude API allows you to send messages to your users. contact: email: support@prelude.so servers: - url: https://api.prelude.dev description: Production server security: - apiToken: [] tags: - name: Notify description: Send transactional and marketing messages with compliance enforcement. - name: Transactional description: Send transactional messages (deprecated - use Notify API instead). - name: Verify description: Verify phone numbers. - name: Watch description: Evaluate email addresses and phone numbers for trustworthiness. - name: Lookup description: >- Retrieve detailed information about a phone number including carrier data, line type, and portability status. paths: /v2/watch/management/rules/{rule_id}: put: tags: - Watch summary: Replace a rule description: >- **Beta.** The request and response shapes may still change. Overwrite a rule in place. The body is the whole rule, not a patch: what you omit is cleared. The new expression is compiled before it is stored. It is not re-checked against the recipes already scoring over this rule, so an edit that drops an attribute or parameter reference is accepted here and the rule is reported as unavailable at evaluation time. Re-save the recipe to validate the association. operationId: replaceWatchRule parameters: - name: rule_id in: path required: true schema: type: string examples: - rul_01jc0t6fwwfgfsq1md24mhyztj description: The rule identifier. requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/WatchRuleRequest' responses: '200': description: OK content: application/json: schema: $ref: '#/components/schemas/WatchRule' '400': description: KO content: application/json: schema: $ref: '#/components/schemas/Error' '403': description: Forbidden content: application/json: schema: allOf: - $ref: '#/components/schemas/Error' example: code: managed_rule_read_only message: >- This rule is managed by Prelude and cannot be edited or deleted. type: forbidden request_id: 3d19215e-2991-4a05-a41a-527314e6ff6a '404': description: Not Found content: application/json: schema: $ref: '#/components/schemas/Error' components: schemas: WatchRuleRequest: type: object properties: name: type: string maxLength: 128 description: >- A label for the rule. It is returned in evaluation results, so make it say what the rule looks for. examples: - free_plan_signup expression: type: string description: > The condition, written in [CEL](https://cel.dev). It must evaluate to a boolean, and it is compiled before it is stored: an expression that does not compile is refused. It may reference the signals Prelude resolves for an evaluation, a recipe's request attributes as `attr.`, and a recipe's configured values as `param.`. A rule that references either namespace is bound to the recipes declaring those names, and can only be used by them. See [Rules, recipes and flows](/watch/v2/documentation/rules-recipes-flows#writing-an-expression); the signal vocabulary is not published yet, so contact us for the names available to your rules. examples: - attr.plan_tier == "free" required: - name - expression WatchRule: type: object properties: id: type: string examples: - rul_01jc0t6fwwfgfsq1md24mhyztj description: >- The rule identifier. Reference it in a recipe's `rules` to score over it. name: type: string examples: - free_plan_signup expression: type: string examples: - attr.plan_tier == "free" type: type: string enum: - CUSTOM description: >- Always `CUSTOM`. A rule you author is your own; Prelude's are a separate, read-only listing. required: - id - name - expression - type Error: type: object properties: code: type: string description: The error code. examples: - invalid_phone_number message: type: string examples: - >- The provided phone number is invalid. Provide a valid E.164 phone number. description: A human-readable message describing the error. type: type: string examples: - bad_request description: The error type. request_id: type: string examples: - 3d19215e-2991-4a05-a41a-527314e6ff6a description: >- A string that identifies this specific request. Report it back to us to help us diagnose your issues. param: type: string examples: - phone_number description: The parameter the error refers to, when it applies to a single one. required: - code - message - type securitySchemes: apiToken: type: http scheme: bearer ````