Response Headers
Every response from the gateway includes metadata headers.
Standard headers
| Header | Description | Example |
|---|---|---|
X-Generation-Id | Unique request ID | gen_01J5K7ABCD... |
X-Tangle-Price-Input | USD per input token | 0.000003 |
X-Tangle-Price-Output | USD per output token | 0.000015 |
X-Tangle-Cache | Response cache status | HIT or MISS |
X-RateLimit-Limit | Requests allowed per window | 60 |
X-RateLimit-Remaining | Requests remaining | 42 |
X-RateLimit-Reset | Window reset (Unix seconds) | 1712793600 |
Conditional headers
| Header | When present | Description |
|---|---|---|
X-Tangle-Routing-Trace | When ENABLE_ROUTING_TRACE is on | Compact routing path |
X-Tangle-Operator | When served by an operator | Operator slug |
X-Tangle-BYOK | When BYOK credentials used | true |
X-Tangle-Caching | When prompt caching applied | auto |
X-Tangle-Guardrails | When guardrails flagged content | pii:low,prompt_injection:high |
X-Payment-Settled | When SpendAuth payment succeeded | true |
X-Free-Tier-Remaining | Free tier requests | 3 |
X-Free-Tier-Limit | Free tier daily cap | 5 |
Error response headers
| Header | When present | Description |
|---|---|---|
X-Payment-Required | 402 responses | Amount needed (micro-USD) |
X-Payment-Currency | 402 responses | tsUSD |
X-Payment-Methods | 402 responses | credits,spend_auth |