{"meta":{"title":"User prompt transformed hook","intro":"The userPromptTransformed hook runs after the runtime adds generated context to a submitted prompt, but before the resulting content is persisted to session history or sent to the model.","product":"GitHub Copilot","breadcrumbs":[{"href":"/en/copilot","title":"GitHub Copilot"},{"href":"/en/copilot/how-tos","title":"How-tos"},{"href":"/en/copilot/how-tos/copilot-sdk","title":"Copilot SDK"},{"href":"/en/copilot/how-tos/copilot-sdk/hooks","title":"Use hooks"},{"href":"/en/copilot/how-tos/copilot-sdk/hooks/user-prompt-transformed","title":"User prompt transformed"}],"documentType":"article"},"body":"# User prompt transformed hook\n\nThe userPromptTransformed hook runs after the runtime adds generated context to a submitted prompt, but before the resulting content is persisted to session history or sent to the model.\n\n<!-- markdownlint-disable GHD046 GHD005 -->\n<!-- Suppressed: GHD046 (outdated release terminology), GHD005 (hardcoded data variable) -->\n\nUse it when you need to inspect or replace the exact model-facing prompt. The `prompt` input contains the user prompt after any `userPromptSubmitted` hooks have run, while `transformedPrompt` also contains runtime-generated context such as `<current_datetime>`.\n\n## Input and output\n\n| Input field | Type | Description |\n| --- | --- | --- |\n| `sessionId` | string | Runtime session ID |\n| `timestamp` | date/time | Time the hook was invoked |\n| `cwd` / `workingDirectory` | string | Current working directory |\n| `prompt` | string | Prompt after `userPromptSubmitted` hooks |\n| `transformedPrompt` | string | Model-facing prompt after runtime transformations |\n\nReturn no value to leave the transformed prompt unchanged. Return `modifiedTransformedPrompt` to replace the content that is stored in session history and sent to the model.\n\n## Examples\n\n<div class=\"ghd-codetabs\">\n<div class=\"ghd-codetab\" data-lang=\"typescript\" data-label=\"TypeScript\"><div class=\"ghd-codetab-fallback-label\" role=\"heading\" aria-level=\"3\">TypeScript</div>\n\n<!-- docs-validate: skip -->\n\n```typescript\nconst session = await client.createSession({\n  hooks: {\n    onUserPromptTransformed: async (input) => ({\n      modifiedTransformedPrompt: redact(input.transformedPrompt),\n    }),\n  },\n});\n```\n\n</div>\n\n<div class=\"ghd-codetab\" data-lang=\"python\" data-label=\"Python\"><div class=\"ghd-codetab-fallback-label\" role=\"heading\" aria-level=\"3\">Python</div>\n\n<!-- docs-validate: skip -->\n\n```python\nsession = await client.create_session(\n    hooks={\n        \"on_user_prompt_transformed\": lambda input_data, invocation: {\n            \"modifiedTransformedPrompt\": redact(input_data[\"transformedPrompt\"])\n        }\n    }\n)\n```\n\n</div>\n\n<div class=\"ghd-codetab\" data-lang=\"go\" data-label=\"Go\"><div class=\"ghd-codetab-fallback-label\" role=\"heading\" aria-level=\"3\">Go</div>\n\n<!-- docs-validate: skip -->\n\n```golang\nsession, err := client.CreateSession(ctx, &copilot.SessionConfig{\n\tHooks: &copilot.SessionHooks{\n\t\tOnUserPromptTransformed: func(input copilot.UserPromptTransformedHookInput, invocation copilot.HookInvocation) (*copilot.UserPromptTransformedHookOutput, error) {\n\t\t\treturn &copilot.UserPromptTransformedHookOutput{\n\t\t\t\tModifiedTransformedPrompt: copilot.String(redact(input.TransformedPrompt)),\n\t\t\t}, nil\n\t\t},\n\t},\n})\n```\n\n</div>\n\n<div class=\"ghd-codetab\" data-lang=\"dotnet\" data-label=\".NET\"><div class=\"ghd-codetab-fallback-label\" role=\"heading\" aria-level=\"3\">.NET</div>\n\n<!-- docs-validate: skip -->\n\n```csharp\nvar session = await client.CreateSessionAsync(new SessionConfig\n{\n    Hooks = new SessionHooks\n    {\n        OnUserPromptTransformed = (input, invocation) =>\n            Task.FromResult<UserPromptTransformedHookOutput?>(new()\n            {\n                ModifiedTransformedPrompt = Redact(input.TransformedPrompt),\n            }),\n    },\n});\n```\n\n</div>\n\n<div class=\"ghd-codetab\" data-lang=\"java\" data-label=\"Java\"><div class=\"ghd-codetab-fallback-label\" role=\"heading\" aria-level=\"3\">Java</div>\n\n<!-- docs-validate: skip -->\n\n```java\nvar hooks = new SessionHooks().setOnUserPromptTransformed((input, invocation) ->\n    CompletableFuture.completedFuture(\n        new UserPromptTransformedHookOutput(redact(input.transformedPrompt()))));\n\nvar session = client.createSession(new SessionConfig().setHooks(hooks)).get();\n```\n\n</div>\n\n<div class=\"ghd-codetab\" data-lang=\"rust\" data-label=\"Rust\"><div class=\"ghd-codetab-fallback-label\" role=\"heading\" aria-level=\"3\">Rust</div>\n\n```rust\n#[async_trait]\nimpl SessionHooks for MyHooks {\n    async fn on_user_prompt_transformed(\n        &self,\n        input: UserPromptTransformedInput,\n        _ctx: HookContext,\n    ) -> Option<UserPromptTransformedOutput> {\n        Some(UserPromptTransformedOutput {\n            modified_transformed_prompt: Some(redact(&input.transformed_prompt)),\n        })\n    }\n}\n\nlet session = client\n    .create_session(SessionConfig::default().with_hooks(Arc::new(MyHooks)))\n    .await?;\n```\n\n</div>\n\n</div>\n\nThe replacement is persisted as the user message content, so resumed sessions replay the modified content unchanged."}