Worker settings

Environment variables

Set local values in worker/.dev.vars (copy from .dev.vars.example); production values live in wrangler.toml [vars] or as encrypted secrets.

Variable	Required	Default	Description
ANTHROPIC_API_KEY	Yes	—	Anthropic API key. Always set as a secret: npx wrangler secret put ANTHROPIC_API_KEY
ALLOWED_ORIGIN	Yes	http://localhost:5173	Origin(s) allowed by CORS. Accepts a comma-separated list, e.g. https://a.example,https://b.example. Any http://localhost:* origin is always allowed for development
CLAUDE_MODEL	No	claude-haiku-4-5-20251001	Claude model used for replies
MAX_TOKENS	No	1024	Max response tokens
RATE_LIMIT_MINUTE	No	10	Requests per minute per IP
RATE_LIMIT_HOUR	No	50	Requests per hour per IP
ATTACHMENTS_ENABLED	No	true	Accept image/PDF attachments on user messages
ATTACHMENT_TYPES	No	JPEG, PNG, GIF, WebP, PDF	Comma-separated MIME allowlist
ATTACHMENT_MAX_BYTES	No	5242880	Per-file size cap (5 MB)
ATTACHMENT_MAX_COUNT	No	5	Files per message
ATTACHMENT_MAX_REQUEST_BYTES	No	20971520	Attachment bytes forwarded to Claude per request (20 MB)
ATTACHMENT_QUOTA_IP_BYTES	No	52428800	Upload bytes per IP per UTC day (50 MB); 0 disables
ATTACHMENT_QUOTA_TENANT_BYTES	No	524288000	Upload bytes per tenant per UTC day (500 MB); 0 disables
TENANT_ID	No	Origin host	Quota tenant identifier
ATTACHMENT_STORAGE	No	passthrough	passthrough (forward and discard) or r2 (store with retention)
ATTACHMENT_RETENTION_HOURS	No	24	R2 mode: lifetime of stored files and signed URLs
ATTACHMENT_SIGNING_SECRET	R2 only	—	Secret for signing download URLs. Set as a secret

See Attachments for how these fit together, the storage backends, and the privacy posture.

Bindings

Binding	Required	Purpose
RATE_LIMIT (KV)	Yes	Per-IP rate-limit counters and daily attachment quotas. Create with npx wrangler kv namespace create RATE_LIMIT
ANALYTICS_DB (D1)	No	Metadata-only analytics events. When absent, the chat endpoint works normally and skips recording
ATTACHMENTS (R2)	R2 only	Stores uploaded files when ATTACHMENT_STORAGE=r2. Create with npx wrangler r2 bucket create claudius-attachments

See Deploy the worker for the exact wrangler commands.

System prompt

The bot’s personality, knowledge, and guardrails live in worker/src/system-prompt.ts. The repo ships a generic template; edit it to describe your business, services, pricing, and FAQ. The prompt also includes behavioral rules (response length, formatting, prompt-injection protection, when to recommend a contact form).

Redeploy the worker after editing:

cd worker
npx wrangler deploy

Input limits

The worker validates every request before calling Claude:

• messages is required and non-empty
• At most 100 messages per request
• Each message’s content is truncated to 2,000 characters
• Roles must be user or assistant
• A message must have text, attachments, or both
• Attachments: allowlisted type matching the file’s bytes, at most ATTACHMENT_MAX_COUNT per user message, each under ATTACHMENT_MAX_BYTES

Violations return 400 with code VALIDATION_ERROR (or an ATTACHMENT_* code) — see the REST API reference.