Supported Headers
This is the first header you will use, which authenticates you to send requests to the Helicone API. Here’s the format:
"Helicone-Auth": "Bearer <HELICONE_API_KEY>". Remember to replace it with your actual Helicone API key.When adding the
Helicone-Auth make sure the key you add has write permissions. As of June 2024 all keys have write access.The URL to proxy the request to when using gateway.helicone.ai. For example,
https://api.openai.com/.The URL to proxy the request to when using oai.helicone.ai. For example,
https://[YOUR_AZURE_DOMAIN].openai.azure.com.The ID of the request, in the format:
123e4567-e89b-12d3-a456-426614174000Overrides the model used to calculate costs and mapping. Useful for when the model does not exist in URL, request or response. For example,
gpt-4-1106-preview.Assigning an ID allows Helicone to associate your prompt with future versions of your prompt, and automatically manage versions on your behalf. For example, both
prompt_story and this is the first prompt are valid.Custom Properties allow you to add any additional information to your requests, such as environment, conversation, or app IDs. Here are some examples of custom property headers and values:
Helicone-Property-Session: 121, Helicone-Property-App: mobile, or Helicone-Property-MyUser: John Doe. There are no restrictions on the value.Specify the user making the request to track and analyze user metrics, such as the number of requests, costs, and activity associated with that particular user. For example,
[email protected] or db513bc9-ff1b-4747-a47b-7750d0c701d3 are both valid.Utilize any provider through a single endpoint by setting fallbacks. See how it’s used in Gateway Fallbacks.
Set up a rate limit policy. The value should follow the format:
[quota];w=[time_window];u=[unit];s=[segment]. For example, 10;w=1000;u=cents;s=user is a policy that allows 10 cents of requests per 1000 seconds per user.Add a
Helicone-Session-Id header to your request to start tracking your (sessions and traces.)[features/sessions].To represent parent and child traces we take advantage of a simple path syntax. For example, if you have a parent trace
parent and a child trace child, you can represent this as parent/child.The name of the session. For example,
Course Plan.3rd Party Integrations
PostHog authentication for Helicone’s PostHog
Integration
PostHog host for Helicone’s PostHog
Integration
Feature Flags
Whether to exclude the response from the request. Set to
true or false.Whether to exclude the request from the response. Set to
true or false.Control how Helicone handles requests that would exceed a model’s context window. Accepted values:
truncate— Best-effort normalization and trimming of message content to reduce token count.middle-out— Preserve the beginning and end of messages while removing middle content to fit within the limit. Uses token estimation to keep high-value context.fallback— Switch to an alternate model when input exceeds the context limit. Provide multiple candidates in the request body’smodelfield as a comma-separated list (e.g.,"gpt-4o, gpt-4o-mini"). Helicone picks the second model as the fallback when needed. When under the limit, Helicone normalizes themodelfield to the primary model.
If your request body does not include a
model or you need to override it for estimation, set Helicone-Model-Override. For fallbacks, specify multiple model candidates in the body; only the first two are considered.Whether to cache your responses. Set to
true or false. You can customize the behavior of the cache feature by setting additional headers in your request.Additional headers
Additional headers
| Parameter | Description |
|---|---|
Cache-control | Specify the cache limit as a string in seconds, i.e. max-age=3600 is 1 hour. |
Helicone-Cache-Bucket-Max-Size | The size of cache bucket represented as a number. |
Helicone-Cache-Seed | Define a separate cache state as a string to generate predictable results, i.e. user-123. |
Header values have to be strings. For example,
"Helicone-Cache-Bucket-Max-Size": "10". Retry requests to overcome rate limits and overloaded servers. Set to
true or false.
You can customize the behavior of the retries feature by setting additional headers in your request.Additional headers
Additional headers
| Parameter | Descriptionretru |
|---|---|
helicone-retry-num | Number of retries as a number. |
helicone-retry-factor | Exponential backoff factor as a number. |
helicone-retry-min-timeout | Minimum timeout (in milliseconds) between retries as a number. |
helicone-retry-max-timeout | Maximum timeout (in milliseconds) between retries as a number. |
Header values have to be strings. For example,
"helicone-retry-num": "3". Activate OpenAI moderation to safeguard your chat completions. Set to
true or false.Secure OpenAI chat completions against prompt injections. Set to
true or false.Enforce proper stream formatting for libraries that do not inherently support it, such as Ruby. Set to
true or false.Response Headers
| Headers | Description |
|---|---|
Helicone-Id | Indicates the ID of the request. |
Helicone-Cache | Indicates whether the response was cached. Returns HIT or MISS. |
Helicone-Cache-Bucket-Idx | Indicates the cache bucket index used as a number. |
Helicone-Fallback-Index | Indicates fallback idex used as a number. |
Helicone-RateLimit-Limit | Indicates the quota for the number of requests allowed in the time window. |
Helicone-RateLimit-Remaining | Indicates the remaining quota in the current window as a number. |
Helicone-RateLimit-Policy | Indicates the active rate limit policy. |