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Configure

Return deterministic configuration to your applications.

Send a flag key, an identifier, and attributes. Flowyn evaluates the rules in order, applies any percentage rollout with a stable bucket, and returns a typed value plus the reason it was chosen.

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Context received
test
checkout_v2
Context
environment
production
user_id
usr_142
plan
pro
country
DE
Rules · same input, same path, every time
Rule 1environment is stagingpending
Rule 2plan is enterprisepending
Rollout25% by user_idpending
Problem

What teams build again and again

Hard-coded switches need a deploy. Home-grown flag tables drift between environments, and nobody can explain why one user saw the new checkout and another did not.

What Flowyn provides

  • 01Boolean, string, number, and JSON values
  • 02Environment-aware values: test and live
  • 03Rules evaluated in order against caller-supplied attributes
  • 04Percentage rollouts bucketed on a stable identifier
  • 05The reason and matched rule returned with every evaluation
Behavior

What exactly happens

At the product-contract level. This is what your application and your agent can rely on.

  1. 01

    Define

    Your application sends the flag key, an identifier, and attributes. Flowyn does not invent attributes.

  2. 02

    Evaluate

    Rules are evaluated in order. The first matching rule wins.

  3. 03

    Decide

    A percentage condition hashes the identifier into a bucket from 0 to 9,999. The same identifier always lands in the same bucket.

  4. 04

    Return

    The response contains the value, the reason, the matched rule, and the bucket.

Statestargeting_matchpercentage_rolloutdefaultdisabled
Capabilities

Everything around the configure operation.

POST /v1/flags/evaluate

Deterministic evaluation

A flag key, an identifier, and attributes go in. A typed value and the reason for that value come out. The same input always produces the same output.

Explore Percentage rollout

Percentage rollouts

A flag key, a percentage in basis points, and a stable identifier go in. Included or excluded, with the reason and bucket, comes out.

Explore
API example

One request. One resource you can read back.

Exact schemas are in the docs and OpenAPI.

For coding agents

Agents read configuration the same way applications do: one POST returns a typed value and the reason. There is no SDK state to reason about, and the same input always produces the same answer.

POSThttps://api.flowyn.dev/v1/flags/evaluate200
curl -X POST https://api.flowyn.dev/v1/flags/evaluate \
  -H "Authorization: Bearer flw_test_••••" \
  -H "Content-Type: application/json" \
  -d '{
    "key": "checkout_v2",
    "identifier": "usr_142",
    "attributes": {
      "plan": "pro"
    }
  }'

Also on Flowyn

Flags & remote configuration stays inside Flowyn's boundary: observe, verify, evaluate, execute bounded work, and report the result. The same account, API keys, and history cover every product.

Frequently asked questions

Is evaluation deterministic?
Yes. The same flag configuration, identifier, and attributes always return the same value. Rollouts hash a stable identifier into a bucket.
Who supplies the attributes?
Your application. Flowyn evaluates what you send and never guesses user attributes.
Can I read the reason?
Yes. Every response includes the reason, the matched rule, and, for rollouts, the bucket.

Start with flags & remote configuration.

Create a workspace, make your first call in the test environment, and inspect every attempt.

Start building Read the docs