Return the calling tenant's identity, plan tier, current usage counters (storage bytes, monthly requests, active links), and rate limits. Use this once at the start of an agent run to confirm authentication and to size subsequent operations against quota. Free of side effects and quota-cheap.

List artifacts owned by the calling tenant, newest first. Supports filters by session_id, agent_id, filename (exact match), content_type, created_after / created_before (ISO 8601), and one or more metadata.<key>=<value> pairs (multi-key requires Pro). Returns a page of artifact records and a next_cursor to fetch the next page. Use this to discover what an agent or pipeline produced when you only know a session or agent ID.

Fetch metadata for a single artifact by ID: filename, content type, size, content hash, session/agent IDs, custom metadata, expiry, creation timestamp. Does NOT return the file bytes — call get_artifact_download_url for that. Returns artifact_not_found for unknown IDs, artifact_already_deleted (HTTP 410) for soft-deleted ones, artifact_expired (410) for those past their TTL.

Generate a short-lived presigned URL (1 hour) the agent can use to download the artifact's bytes directly from Cloudflare R2. Use this when the agent itself needs to consume the file. For sharing with humans, use create_download_link instead — that produces a stable dl.artifacta.io/lnk_… URL with configurable expiry.

List session IDs synthesized from the calling tenant's artifacts, ordered by most recent activity. Each entry includes artifact count, seal status, and first/last activity timestamps. Sessions are not first-class — they exist only as long as artifacts reference them.

Upload a file as a new artifact in a single call. Provide EITHER up to ~10 MB of base64-encoded bytes via content, OR a local filesystem path that the MCP server reads and streams as multipart/form-data (up to 500 MB). For files larger than 500 MB, use request_upload_url (Pro only) instead — store_artifact returns file_too_large for them. Tags the artifact with session_id / agent_id / metadata for later retrieval and returns the full artifact record including its new artifact_id and content_hash.

Path uploads are confined. The path argument is constrained to the launcher-configured allow-list (default: the MCP server's CWD). Paths outside the allow-list, paths traversing symlinks out of it, and paths to known-sensitive locations (~/.ssh, ~/.aws, /etc/, etc.) are refused with invalid_request.

For crash-safe retries, supply your own idempotency_key (any string ≤256 chars): a replay within 24h returns the original artifact and never double-bills. If you omit it, the server auto-generates one and returns it under _meta.idempotency_key, but that key protects only in-process retries within a single call — it is lost if the server restarts, so pre-commit your own key when durability matters.

Reserve a presigned R2 PUT URL for a file too large to send through store_artifact (over 500 MB up to 5 GB). Returns an upload_url, headers to include in the PUT, and an artifact_id in pending state. The agent (or its environment) PUTs the bytes directly to R2, then calls complete_upload. Pro plan only. Most agents should use store_artifact and let the MCP server pick the path automatically.

Not retry-safe: this endpoint does not support idempotency keys, so on an HTTP 5xx or network error the reservation may or may not have been created. Do NOT blindly retry — the error guidance tells you to first call list_artifacts with the same session_id/agent_id to detect any pending artifact, so you don't create a duplicate.

Finalize an artifact previously reserved via request_upload_url after the bytes have been PUT to the presigned URL. Server verifies the blob, computes the content hash, transitions the artifact from pending to active, and increments tenant usage. Calling this on an already-active artifact is idempotent and returns the existing record. Calling before the PUT completes returns upload_not_found — wait and retry.