com.blockether.svar.internal.router — com.blockether/svar 0.2.0

Router: provider/model registry, circuit breakers, rate limiting, budget tracking, and routing resolution.

Extracted from defaults.clj (provider/model metadata) and llm.clj (routing logic) to provide a single cohesive namespace for all routing concerns.

check-context-limit clj

(check-context-limit model messages)

(check-context-limit model
                     messages
                     {:keys [output-reserve throw? context-limits]
                      :or {output-reserve DEFAULT_OUTPUT_RESERVE throw? false}})

Checks if messages fit within model context limit.

context-limit clj

(context-limit model)

(context-limit model context-limits)

Returns the maximum context window size for a model.

Params: model - String. Model name. context-limits - Map, optional. Override map (merged defaults from config).

Returns: Integer. Maximum context tokens.

count-and-estimate clj

(count-and-estimate model messages output-text)

(count-and-estimate model
                    messages
                    output-text
                    {:keys [pricing input-tokens api-usage]})

Counts tokens and estimates cost in one call.

count-messages clj

(count-messages model messages)

Counts tokens for a chat completion message array.

count-tokens clj

(count-tokens model text)

Counts tokens for a given text string using the specified model's encoding.

DEFAULT_OUTPUT_RESERVE clj

Default number of tokens to reserve for model output. 0 means no reservation — let the API handle overflow naturally.

DEFAULT_RETRY clj

Default retry policy for transient HTTP errors.

DEFAULT_TIMEOUT_MS clj

Default HTTP request timeout in milliseconds (5 minutes). Reasoning models (e.g. glm-5-turbo) may need extended time for chain-of-thought.

estimate-cost clj

(estimate-cost model input-tokens output-tokens)

(estimate-cost model input-tokens output-tokens pricing-map)

Estimates the cost in USD for a given token count.

format-cost clj

(format-cost cost)

Formats a cost value as a human-readable USD string.

infer-model-metadata clj

(infer-model-metadata {:keys [name] :as model-map})

Returns provider-independent model metadata. Looks up KNOWN_MODEL_METADATA first. Falls back to regex inference for unknown models. Explicit fields in model-map override inferred values.

KNOWN_MODEL_METADATA clj

KNOWN_PROVIDER_MODELS clj

KNOWN_PROVIDERS clj

make-router clj

(make-router providers)

(make-router providers opts)

Creates a router from a vector of provider maps.

Vector order = priority (first provider is highest priority). First model in provider vector = root model. Provider :base-url auto-resolved from KNOWN_PROVIDERS for known IDs. Model metadata auto-inferred from :name and merged with provider-scoped pricing/context. Duplicate provider :id values are a hard error.

opts - Optional map: :network - {:timeout-ms N :max-retries N ...} router-level network defaults :tokens - {:check-context? bool :pricing {} :context-limits {}} token defaults :budget - {:max-tokens N :max-cost N} spend limits (nil = no limit) :failure-threshold - Int. Failures before circuit opens (default: 5) :recovery-ms - Int. Ms before open→half-open (default: 60000)

Example: (make-router [{:id :blockether :api-key <key> :models [{:name <model-a>} {:name <model-b>}]} {:id :openai :api-key <key> :models [{:name <model-a>} {:name <model-b>}]}] {:budget {:max-tokens 1000000 :max-cost 5.0}})

max-input-tokens clj

(max-input-tokens model)

(max-input-tokens model {:keys [output-reserve trim-ratio context-limits]})

Calculates maximum input tokens for a model, reserving space for output.

MODEL_CONTEXT_LIMITS clj

Best-effort flattened model context limits for legacy token utilities. When a model exists on multiple providers with different contexts, the maximum is used.

MODEL_PRICING clj

Best-effort flattened model pricing for legacy token utilities. When a model exists on multiple providers, the lowest total pricing is chosen. Provider-aware code should NOT use this — use provider-model-pricing instead.

normalize-model clj

(normalize-model model-map)

Normalizes a model entry: {:name "gpt-4o"} -> full provider-independent model metadata.

normalize-provider clj

(normalize-provider idx provider-map)

Normalizes a provider entry:

• resolves :base-url from KNOWN_PROVIDERS if not provided
• derives :priority from vector index
• derives :root from first model
• merges provider-independent model metadata with provider-scoped pricing/context

provider-model-context clj

(provider-model-context provider-id model-name)

Returns provider-scoped context window for provider/model, falling back to flattened MODEL_CONTEXT_LIMITS.

provider-model-entry clj

(provider-model-entry provider-id model-name)

Returns provider-scoped entry {:pricing ... :context ...} for a provider/model, or nil.

provider-model-pricing clj

(provider-model-pricing provider-id model-name)

Returns provider-scoped pricing for provider/model, falling back to flattened MODEL_PRICING.

reset-budget! clj

(reset-budget! router)

Resets the router's token/cost budget counters to zero.

reset-provider! clj

(reset-provider! router provider-id)

Manually resets a provider's circuit breaker to :closed.

resolve-routing clj

(resolve-routing router routing-opts)

Resolves :routing opts to prefs for with-provider-fallback. Returns {:prefs prefs-map :error-strategy kw}. Throws on invalid provider/model combinations.

router-stats clj

(router-stats router)

Returns cumulative + windowed stats for the router.

select-provider clj

(select-provider router prefs)

Returns [provider model-map] or nil. Read-only.

truncate-text clj

(truncate-text model text max-tokens)

(truncate-text model
               text
               max-tokens
               {:keys [truncation-marker from] :or {from :end}})

Truncates text to fit within a token limit. Uses proper tokenization to ensure accurate truncation.

with-provider-fallback clj

(with-provider-fallback router prefs f)