Contact CodeSignal to enable API and webhook access for your account; CodeSignal uses a GraphQL API — the endpoint and credentials are provided during onboarding
Configure a webhook in CodeSignal to receive POST notifications when an assessment is completed; the payload includes the candidate identifier, assessment ID, score, and a link to the full report
On webhook receipt, extract the candidate email or external ID and use it to locate the matching candidate record in your ATS
Query the CodeSignal GraphQL API for the detailed result object using the assessmentResultId from the webhook payload to retrieve sub-scores, time-on-task, and percentile data
Write the score and report URL back to the candidate's ATS profile using the ATS write API (e.g., POST a scorecard or tag in Greenhouse, or update a candidate property in Lever)
For native ATS integrations (Greenhouse, Lever, Workday, SmartRecruiters, iCIMS), CodeSignal provides pre-built connectors that push results automatically using the Assess_Candidate method — prefer these over a custom implementation where available
Known gotchas
CodeSignal's API is GraphQL, not REST; standard REST client libraries will not work out of the box — use a GraphQL client or construct POST requests to the GraphQL endpoint with the correct query/mutation syntax
Assessment results are tied to a specific assessment configuration; if the test is updated or replaced, historical result IDs may not map to the new version — version your assessment IDs explicitly
CodeSignal API access requires a partner agreement; self-service API keys are not available — plan for a lead time to get credentials provisioned
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp