Skip to main content

At a glance

  • No session endpoints in REST: the public REST API can’t list sessions, answer questions, approve plans, or send prompts. Use MCP or the web app.
  • Batches group sessions: API-triggered generation and healing return a batchId. Poll until allTerminal is true.
  • Sessions clone the repositories, so they see only pushed commits.
  • Standard runs unattended; Deep pauses for plan approval.
  • Session statuses: Initializing, Cloning, Advancing, Running, Waiting for Input, Waiting for Approval, PR Eligible, Completed, Failed, Cancelled (see Session lifecycle).
Developer guide
Track sessions with the REST API and steer them over MCP

Track sessions from the REST API

When you start generation or healing through the API, you get back a batchId: a handle for one or more sessions working on your request. Check the batch every 10–30 seconds until allTerminal is true. Each session in the list shows its status and, once it’s done, a link to its pull request.
GET
Healing batches work the same way at GET https://api.checksum.ai/public-api/v1/auto-heal/batch/{batchId}. POST /auto-generate also returns links.session, a direct link to the session in the web app.
Sessions have no REST endpoints of their ownThe public REST API doesn’t have endpoints to list sessions, answer questions, approve plans, or send follow-up prompts. Use the web app or the MCP server for those.

GET https://api.checksum.ai/public-api/v1/auto-generate/batch/{batchId}

Status of the sessions in a generation batch. Header: Authorization: Bearer $CHECKSUM_API_KEY. Path parameter batchId (string) from POST /public-api/v1/auto-generate. Full response fields: Generate Tests → Reference for AI.

GET https://api.checksum.ai/public-api/v1/auto-heal/batch/{batchId}

Status of the sessions in a healing batch. Header: Authorization: Bearer $CHECKSUM_API_KEY. Path parameter batchId (string) from POST /public-api/v1/auto-heal or an autoHeal run. Full response and batch status values: Auto-Healing → Poll healing progress.
Polling rule: every 10–30 seconds until allTerminal is true.Not available in REST: list sessions, answer questions, approve plans, send prompts.

Watch and steer sessions from your editor

With the Checksum MCP server connected, your coding agent can follow a session for you: it reports progress, the agent’s latest messages, the files it changed, and the PR it opened. You can also redirect a session that’s already running, just by asking:
That’s the same as typing into the session in the web app. Every result includes links into the web app, so you can open the session instead of copying IDs around. Your agent can also clear the pauses described in The session view without the web app: it approves a deep-mode plan with checksum_session_approve and answers questions with checksum_session_answer. It can stop or restart a session, and open the PR for a finished session that didn’t open one. See Deep mode and the approval loop.
Which sessions accept promptsRunning, waiting, paused, and completed sessions accept a prompt, and a prompt resumes a stopped session. A session that was cancelled, or failed without a way back, won’t accept one, and you’ll get an error saying so.
MCP server: https://api.checksum.ai/public-api/mcp.Constraint: checksum_session_prompt fails with an error on a session that was cancelled or failed without a way back. Results include web-app links.
▦
In the Checksum web app
The session view, questions, and approvals

The session view

Open Agent Sessions in the web app to see every session in your project. Each one shows:
  • Status: the current lifecycle stage
  • Pipeline stages: which stages are done and which are next
  • Duration: how long the session has been running
  • Results: generated files and the PR link, once it completes

Answer the agent’s questions

When the session is Waiting for Input, the agent’s questions appear in the session view. Common ones:
  • “Which features should I focus on?”
  • “How does the login flow work for admin users?”
  • “Should I include negative test cases?”
Type your answers and submit. The agent picks up where it left off. Several questions may be waiting at once.
Give detailed answers. The more context the agent has, the better the results.

Approve plans at approval gates

When the session is Waiting for Approval, review what the agent produced, such as a plan or a set of detected flows. Click Approve to continue, or cancel if you want to adjust.
i
How it works
Session statuses, modes, and what starts a session

Session lifecycle

Agent Sessions list in the web app

The Agent Sessions page lists every session with its status and pipeline stage.

A completed agent session showing pipeline stages and results

A completed session: pipeline stages, generated files, and the PR link.

Standard vs Deep sessions

How much interaction a session needs depends on its mode:
  • Standard is fully autonomous. The agent runs from start to finish without any input. You can start many sessions in parallel and come back to finished results.
  • Deep needs you for the first step (planning). The agent presents a plan and waits for your approval. After that, the remaining steps run on their own.
In practiceLaunch 10 Standard sessions and walk away. For Deep sessions, review and approve each plan, then leave them to finish.

What starts a session?

Each of these creates its own independent session:

Troubleshooting

Check that the Git integration is Active in Settings → Git Integration, and that the branch you referenced exists on the remote.
Check the environment URL and test users in Environments. If the environment is behind a VPN or firewall, allowlist Checksum’s IPs (Security & Access).
Sessions don’t continue until you answer. Open the session and respond. From your coding agent, answer with checksum_session_answer (or approve a waiting plan with checksum_session_approve).
The session is PR Eligible. Create the PR from the session view. This happens when the trigger had no pull-request context.

Deep vs Standard

Why some sessions ask for approval.

Generate Tests

Every way to start a generation session.

Auto-Healing

Healing sessions and batches.

Coding Agents & MCP

Steer sessions from your editor.