RAIS Compliance

Verify that any server is RAIS Protocol v1 compliant using the rais-compliance CLI.

Run compliance tests

npx rais-compliance http://localhost:3001/api/chat

Don't have a server yet? Start the built-in mock server:

npx rais-compliance serve
# → http://localhost:3001/api/chat
 
# Then in another terminal:
npx rais-compliance http://localhost:3001/api/chat

Example output:

RAIS Protocol v1 Compliance Test
Endpoint: http://localhost:3001/api/chat

  MUST (normative)
    headers.content-type           ✓ Content-Type is text/event-stream
    headers.cache-control          ✓ Cache-Control: no-cache present
    events.format                  ✓ All 12 data lines are valid JSON
    events.text-type               ✓ All 10 text events have a "text" string field
    events.done                    ✓ Exactly one done event, last in stream
    events.no-after-done           ✓ No events emitted after done
    events.has-text-tokens         ✓ Received 10 text token(s)

  SHOULD (recommended)
    headers.accel-buffering        ⚠ X-Accel-Buffering header not set
    events.sse-id                  ⚠ No id: fields — add SSE event IDs for reconnect safety

  ⚠  2 warned · 7 passed

  RAIS v1 Core compliant (warnings present)
  Fix warnings to reach RAIS v1 Recommended

Custom test messages

npx rais-compliance http://localhost:3001/api/chat \
  --messages '[{"role":"user","content":"Respond with one sentence."}]'

Certification levels

Level	Criteria
RAIS v1 Core	All MUST tests pass
RAIS v1 Recommended	All MUST + SHOULD tests pass
RAIS v1 Full	Recommended + reconnect support (`id:` + `Last-Event-ID`)

What gets tested

MUST (failures block certification)

Test	What it checks
`headers.content-type`	Response has `Content-Type: text/event-stream`
`headers.cache-control`	Response has `Cache-Control: no-cache`
`events.format`	Every `data:` line is valid JSON
`events.text-type`	Every `text` event has a `text` string field
`events.done`	Stream ends with exactly one `done` event
`events.no-after-done`	No events emitted after `done`
`events.has-text-tokens`	At least one `text` token received

SHOULD (warnings only)

Test	What it checks
`headers.accel-buffering`	`X-Accel-Buffering: no` is set (nginx proxy safety)
`events.sse-id`	Events have `id:` fields for reconnect support

Fixing common failures

⚠️

Missing Content-Type: text/event-stream — Set this header before writing any response body. In Express: res.setHeader('Content-Type', 'text/event-stream'). In Next.js: include it in the Response headers.

⚠️

No done event — Your server must emit data: {"type":"done"}\n\n when the LLM finishes. Without it, clients wait forever for a stream that is already complete.

X-Accel-Buffering warning — Only needed when running behind nginx. Add X-Accel-Buffering: no to prevent nginx from buffering the SSE stream. Without it, nginx may hold events until its buffer fills.

Mock server scenarios

Use the built-in mock server to test specific edge cases:

npx rais-compliance serve --scenario slow       # 200ms between tokens — test buffer logic
npx rais-compliance serve --scenario error      # partial stream then error event
npx rais-compliance serve --scenario malformed  # non-JSON lines + unknown event types
npx rais-compliance serve --scenario chunked    # events split across network writes
npx rais-compliance serve --scenario no-done    # intentional compliance failure — no done event
npx rais-compliance serve --port 4000           # custom port

Scenario	Expected result
`normal`	RAIS v1 Recommended
`slow`	All MUST pass
`error`	All MUST pass — error terminates stream correctly
`malformed`	All MUST pass — malformed lines skipped gracefully
`chunked`	All MUST pass — buffer logic correct
`no-done`	`events.done` FAILS — intentional

Full compliance checklist

The complete normative checklist is in rais-spec/COMPLIANCE.md (opens in a new tab).

The formal specification is in rais-spec/SPEC.md (opens in a new tab).

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