Recommended Workflow
We recommend a systematic approach to implementing automated evaluations: This approach enables two powerful use cases:1. Nightly Evaluations (Production Monitoring)
Run scheduled evaluations to ensure nothing has changed in your production system. The score can be sent to Slack or your alerting system with a direct link to the evaluation pipeline. This helps detect production issues by sampling a wide range of requests and comparing against expected performance.2. CI/CD Integration
Trigger evaluations in your CI/CD pipeline (GitHub, GitLab, etc.) whenever relevant PRs are created. Wait for the evaluation score before proceeding with deployment, to make sure that your changes do not break anything.Complete Example: Building an Evaluation Pipeline
Here’s a complete example of building an evaluation pipeline from scratch using the API.Option A: Single Request (Recommended)
Create the entire pipeline with columns and custom scoring in one API call:Option B: Step-by-Step
For more control, you can create the pipeline and add columns separately:Step-by-Step Implementation
Step 1: Create a Dataset
To run evaluations, you’ll need a dataset against which to test your prompts. PromptLayer now provides a comprehensive set of APIs for dataset management:1.1 Create a Dataset Group
First, create a dataset group to organize your datasets:- Endpoint:
POST /api/public/v2/dataset-groups - Description: Create a new dataset group within a workspace
- Authentication: API key
- Docs Link: Create Dataset Group
1.2 Create a Dataset Version
Once you have a dataset group, you can create dataset versions using two methods:Option A: From Request History
Create a dataset from your existing request logs:- Endpoint:
POST /api/public/v2/dataset-versions/from-filter-params - Description: Create a dataset version by filtering request logs
- Authentication: API key only
- Docs Link: Create Dataset Version from Filter Params
Option B: From File Upload
Upload a CSV or JSON file to create a dataset:- Endpoint:
POST /api/public/v2/dataset-versions/from-file - Description: Create a dataset version by uploading a file
- Authentication: API key only
- Docs Link: Create Dataset Version from File
Step 2: Create an Evaluation Pipeline
Create your evaluation pipeline (called a “report” in the API) by making a POST request to/reports:
- Endpoint:
POST /reports - Description: Creates a new evaluation pipeline
- Authentication: API key
- Docs Link: Create Reports
Request Payload
Response
Step 3: Configure Pipeline Steps
The evaluation pipeline consists of steps, each referred to as a “report column”. Columns execute sequentially from left to right, where each column can reference the outputs of previous columns.- Endpoint:
POST /report-columns - Description: Add a step to your evaluation pipeline
- Authentication: API key
Basic Request Structure
Scoring Columns
By default, only the last column in a pipeline is used for score calculation. To include multiple columns in the final score, setis_part_of_score: true on each column you want to include. The final score will be the average of all included columns.
Column Types Reference
Below is a complete reference of all available column types and their configurations. Each column type serves a specific purpose in your evaluation pipeline.Primary Column Types
PROMPT_TEMPLATE
Executes a prompt template from your Prompt Registry or an inline template defined directly in the configuration. Option A: Registry Reference Reference a prompt template stored in the Prompt Registry:You must provide exactly one of
template (registry reference) or inline_template (inline content) in the configuration. They are mutually exclusive.Chat History Source: For chat-type prompts, you can use
chat_history_source to specify a dataset column containing a list of chat messages (each with role and content fields). These messages are appended to the end of the prompt template before execution, allowing you to test prompts with different conversation histories. The column value should be a JSON array of message objects, e.g. [{"role": "user", "content": "Hello"}, {"role": "assistant", "content": "Hi there!"}].ENDPOINT
Calls a custom API endpoint with data from previous columns.MCP
Executes functions on a Model Context Protocol (MCP) server.HUMAN
Allows manual human input for evaluation.CODE_EXECUTION
Executes Python or JavaScript code for custom logic.CODING_AGENT
Uses an AI coding agent to process data.CONVERSATION_SIMULATOR
Simulates multi-turn conversations for testing chatbots and conversational agents.user_persona_source instead of user_persona to pull the persona from a dataset column for varied test scenarios. Similarly, use conversation_completed_prompt_source to pull completion guidance from a dataset column.
WORKFLOW
Executes a PromptLayer workflow.Node & Column Types
LLM_ASSERTION
Uses an LLM to evaluate assertions about the data.{variable_name} in your assertions and map them to dataset columns using variable_mappings:
prompt_source instead of prompt to read assertions from a dataset column:
AI_DATA_EXTRACTION
Extracts specific data using AI.COMPARE
Compares two columns for equality.CONTAINS
Checks if a column contains specific text.REGEX
Matches a regular expression pattern.REGEX_EXTRACTION
Extracts text using a regex pattern.COSINE_SIMILARITY
Calculates semantic similarity between two texts.ABSOLUTE_NUMERIC_DISTANCE
Calculates absolute distance between numeric values.Helper Column Types
JSON_PATH
Extracts data from JSON using JSONPath.XML_PATH
Extracts data from XML using XPath.PARSE_VALUE
Converts column values to different types.APPLY_DIFF
Applies diff patches to content.VARIABLE
Creates a static value column.ASSERT_VALID
Validates data types (JSON, number, SQL).COALESCE
Returns the first non-null value from multiple columns.COMBINE_COLUMNS
Combines multiple columns into one.COUNT
Counts characters, words, or paragraphs.MATH_OPERATOR
Performs mathematical operations.MIN_MAX
Finds minimum or maximum values.Column Reference Syntax
When configuring columns that reference other columns, use these formats:- Dataset columns: Use the exact column name from your dataset (e.g.,
"question","expected_output") - Previous step columns: Use the exact name you gave to the column (e.g.,
"AI Answer","Validation Result") - Variable columns: For columns of type VARIABLE, reference them by their name
Important Notes
- Column Order Matters: Columns execute left to right. A column can only reference columns to its left.
- Column Names: Must be unique within a pipeline. Use descriptive names.
- Dataset Columns: Are automatically available as the first columns in your pipeline.
- Error Handling: If a column fails, subsequent columns that depend on it will also fail.
- Scoring: If your last column contains all boolean or numeric values, it becomes the evaluation score.
Step 4: Trigger the Evaluation
Once your pipeline is configured, trigger it programmatically using the run endpoint:- Endpoint:
POST /reports/{report_id}/run - Description: Execute the evaluation pipeline with optional dataset refresh
- Docs Link: Run Evaluation Pipeline
Example Payload
Step 5: Monitor and Retrieve Results
You have two options for monitoring evaluation progress:Option A: Polling
Continuously check the report status until completion:- Endpoint:
GET /reports/{report_id} - Description: Retrieve the status and results of a specific report by its ID.
- Docs Link: Get Report Status
Option B: Webhooks
Listen for thereport_finished webhook event for real-time notifications when evaluations complete.
Step 6: Get the Score
Once the evaluation is complete, retrieve the final score:- Endpoint:
GET /reports/{report_id}/score - Description: Fetch the score of a specific report by its ID.
- Docs Link: Get Evaluation Score
Example Response
Step 7: Configure Custom Scoring (Optional)
By default, PromptLayer calculates scores by averaging boolean columns. For more control, you can configure custom scoring logic using Python or JavaScript code.- Endpoint:
PATCH /reports/{report_id}/score-card - Description: Configure which columns to include and optionally provide custom scoring code
- Docs Link: Configure Custom Scoring
Example: Weighted Scoring
Example: All Checks Must Pass
Custom Code Interface
Your custom code receives adata variable containing all evaluation results:
score key (0-100):

