> ## Documentation Index > Fetch the complete documentation index at: https://docs.comfy.org/llms.txt > Use this file to discover all available pages before exploring further. # Live event stream (SSE) > Server-Sent Events stream of the job's live state. On connect the client receives the current snapshot (a `status` event, the latest `progress`, and the most recent `preview` if any), then future updates. The stream ends after either the terminal `status` event or a terminal `error` event (see the `error` event below). Live push only — NOT a replayable log: events carry no `id`, there is no `Last-Event-ID` resume, and frames emitted while disconnected are gone. Each `progress` event is a complete snapshot, so a single one fully re-syncs a reconnecting client; the authoritative state is always `GET /api/v2/jobs/{id}`. ## OpenAPI ````yaml /openapi-v2.yaml get /api/v2/jobs/{id}/events openapi: 3.0.3 info: title: Comfy API v2 version: 2.0.0 description: | The official, versioned HTTP API for running ComfyUI workflows from external applications: upload inputs, submit a workflow, observe execution, retrieve results. Design principles: - **Poll-first.** Every capability is reachable via plain GET polling; the SSE stream is a live enhancement, never the source of truth. - **Everything is resumable.** Submission is idempotent; job state and outputs are retrievable by ID until `expires_at`. - **UUID identity, content-addressed dedup.** Assets are UUID-identified records over blobs keyed by a server-computed blake3 hash. The hash is nullable and may be computed lazily. - **Follow links, don't build URLs.** Responses embed follow-up URLs. Additive changes only within v2; breaking changes require v3. servers: - url: http://127.0.0.1:8189 description: Self-hosted (comfy-api-proxy) - url: https://cloud.comfy.org description: Comfy Cloud - url: https://{deployment}.run.comfy.app description: Serverless deployment variables: deployment: description: >- DNS-safe deployment id (subdomain label). Staging uses {deployment}.stg.run.comfy.app. default: dep-1234abcd-56ef-7890-abcd-ef1234567890 security: - bearerAuth: [] - {} tags: - name: assets description: UUID-identified records over content-addressed blobs. - name: jobs description: One execution of a workflow — durable, pollable, cancelable. paths: /api/v2/jobs/{id}/events: get: tags: - jobs summary: Live event stream (SSE) description: | Server-Sent Events stream of the job's live state. On connect the client receives the current snapshot (a `status` event, the latest `progress`, and the most recent `preview` if any), then future updates. The stream ends after either the terminal `status` event or a terminal `error` event (see the `error` event below). Live push only — NOT a replayable log: events carry no `id`, there is no `Last-Event-ID` resume, and frames emitted while disconnected are gone. Each `progress` event is a complete snapshot, so a single one fully re-syncs a reconnecting client; the authoritative state is always `GET /api/v2/jobs/{id}`. operationId: getJobEvents parameters: - $ref: '#/components/parameters/JobId' responses: '200': description: SSE stream; see `x-sse-events` for the event catalog. content: text/event-stream: schema: type: string description: >- Stream of `event:`/`data:` frames. Data payloads are the JSON schemas listed in x-sse-events. '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '404': $ref: '#/components/responses/NotFound' '429': description: >- `too_many_streams` — the caller already has the maximum number of concurrent GET .../events streams open. Close an existing stream (or wait for one to reach a terminal status) before opening another; GET /api/v2/jobs/{id} remains available as a plain poll regardless of this limit. Or `rate_limited`, the caller past a request rate limit; retry after `Retry-After`. headers: Retry-After: $ref: '#/components/headers/RetryAfter' content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' '500': $ref: '#/components/responses/UpstreamError' '501': description: >- `not_implemented` — this deployment does not yet serve live event streaming. GET /api/v2/jobs/{id} remains available as a plain poll in the meantime. content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' components: parameters: JobId: name: id in: path required: true schema: type: string example: 7f3d2c1b-9a8e-4d6f-b012-3c4d5e6f7a8b responses: Unauthorized: description: '`unauthorized` — missing or invalid credentials.' content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' Forbidden: description: >- `forbidden` — authenticated but not allowed. On a serverless deployment, also `sso_required` — the key is valid, but the account must sign in through its organization's single sign-on, which does not accept this key; it can come back on any operation. content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' NotFound: description: '`not_found`.' content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' UpstreamError: description: >- `upstream_error` — an unexpected failure reaching or processing the request in this implementation's backing services. The message is always a generic, safe-to-display string; implementation detail (the specific upstream, its error text, transport failures) is never included here — see each implementation's own error-mapping notes. Every operation in this contract can fail this way. content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' headers: RetryAfter: schema: type: integer description: Seconds to wait before retrying. schemas: ErrorEnvelope: type: object description: > Shared error envelope with machine-readable codes. Core codes (v1): `invalid_workflow` (422), `workflow_format_ui` (422), `missing_asset` (422), `hash_mismatch` (409), `blob_not_found` (404), `idempotency_key_reuse` (422), `queue_full` (429 + Retry-After), `rate_limited` (429 + Retry-After: the caller is past a request rate limit; retry), `insufficient_credits` (402), `not_found` (404), `unauthorized` (401), `forbidden` (403). Deployment-scoped surfaces add: `deployment_not_ready` (429 + Retry-After — the deployment can still reach ready; retry), `deployment_unavailable` (429 + Retry-After: the deployment is ready but its GPU provider is not taking work on it yet; retry), `deployment_stopped` (422 — terminal deployment state; a retry cannot succeed without operator action), `invalid_request` (422: a malformed asset upload or asset-from-hash field), `content_blocked` (451: content moderation flagged the asset's bytes) and `sso_required` (403: the key is valid, but the account must sign in through its organization's single sign-on, which does not accept this key). A 429 is disambiguated by `error.code` alone; clients should treat any 429 + Retry-After as "back off and retry". required: - error properties: error: type: object required: - code - message properties: code: type: string example: invalid_workflow message: type: string example: 'Node 12 (KSampler): required input ''model'' is not connected' details: type: object nullable: true additionalProperties: true description: >- Machine-readable detail for the code. When it carries `node_errors`, that is keyed by node id and each value is a `JobNodeError`, the same shape as a job's `error.node_errors`, whether the refusal came at submit (for example `unknown_node_class`, a node class the deployment's build does not contain) or from ComfyUI after dispatch. example: node_errors: '12': class_type: SomeCustomNode errors: - type: unknown_node_class message: >- this deployment's build does not contain the node class SomeCustomNode. unknown_node_classes: - SomeCustomNode securitySchemes: bearerAuth: type: http scheme: bearer description: >- `Authorization: Bearer `. The credential is one of: an account-scoped API key (`comfyui-…`), accepted on Cloud and serverless; a Comfy Cloud session JWT; or an OAuth access token issued for the Comfy Cloud resource. Which kinds a given deployment accepts is deployment configuration — an API key always works on Cloud and serverless, and a deployment that does not accept JWT bearers answers `401` with a message saying so. Self-hosted accepts unauthenticated requests by default and can be configured with a static bearer token. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.