models catalog #

The models extension keeps a local copy of the models.dev catalog and answers one question for the rest of Albedo: what is actually known about this model and its provider. It never guesses a limit from a model name.

It is enabled by default and contributes no model tools and no prompt context.

cache #

The catalog is cached at $ALBEDO_HOME/models.json (default ~/.albedo/models.json). Albedo refreshes it when it is missing or older than the refresh window, in the background, and writes it by rename so a partial download is never readable. A failed fetch keeps the previous cache, and the whole file stays as models.dev published it.

{ "models": { "url": "https://models.dev/api.json", "refreshHours": 24 } }

Put this in $ALBEDO_HOME/extensions.json. refreshHours: 0 disables automatic fetching and uses only the cached file, which is what the test suite and air-gapped hosts do. Only https, or http on the loopback host, is fetched.

Run /reload models to fetch the configured catalog immediately, regardless of its age or refreshHours. The command returns only after the cache has been atomically replaced, so the next /model picker reads the new model list. A failed fetch leaves the previous cache in place and reports the failure.

lookup #

A lookup takes the session's model id and its configured provider base url. The endpoint decides between providers that publish the same model id. Without a host match, candidates that agree still answer, and candidates that disagree stay unknown rather than picking one. Both the catalog key and its trailing segment resolve, so vendor/model and model find the same entry.

An answer carries the context window, the maximum output, the input modalities, the provider id, its documented API endpoint, and its expected environment variable names. Everything is reported with its source: the cached file and how the model was matched.

used by #

rolling compaction asks for the context window when contextWindowTokens is not configured, so compaction works without hand-configuring each model. An explicit setting still wins. /context shows the window and names where it came from; an unlisted model stays explicitly unknown.

Provider extensions consume the catalog's endpoint and environment metadata, so authentication and transport policy do not require the daemon to hardcode a model list.

provider extensions #

The catalog also lists model ids by provider or endpoint. /login and /model read those lists only from this cache; they never call a provider's /models endpoint. The openai model-provider extension depends on models and owns API-key configuration plus the shared Responses/Chat Completions client. The codex extension depends on openai; it reuses that request stack and adds only ChatGPT OAuth, account selection, and Codex wire policy. The dependency chain is therefore codex -> openai -> models. antigravity has no dependencies: it brings its own catalog and sign-in, and its upstream drives openai_api.exchange with its own encoder and reducer.

Saved provider profiles carry an extension tag. Existing profiles without one migrate as openai. Codex profiles use extension: "codex" and keep OAuth credentials separately in $ALBEDO_HOME/auth.json; see model authentication.

Codex metadata lookups select the openai provider in models.dev explicitly, including its reasoning effort tiers and context limits. /effort, session defaults, and model switches use this same selection; another provider publishing the same model id cannot replace OpenAI's metadata. No authenticated Codex model catalog is fetched.

antigravity models #

Antigravity is not on models.dev, and its model ids and required model_enum labels change server-side. The antigravity extension therefore contributes its own catalog. It asks Cloud Code Assist fetchAvailableModels which models the account can use, keeps the ids that the real client's agent picker shows, and caches them with their limits, labels, and the renames of retired ids in $ALBEDO_HOME/antigravity.json. The cache refreshes in the background after 6 hours, and the first /login listing waits for discovery. A built-in table supplies each model's thinking control and serves as the list before the first discovery. A saved profile that names a retired id follows the backend's rename. The catalog answers lookups only for the Antigravity endpoint, so models.dev keeps answering for the same ids at other providers.

contribute another catalog #

extension.ModelsPlugin(ModelCatalog(lookup, list)) is the catalog contract. lookup(model, endpoint) returns facts for one model; list(provider, endpoint) returns ids owned by one catalog provider. The first enabled catalog with an answer wins, so a private or offline catalog can be installed ahead of models.dev.

A model transport contributes ModelProviderPlugin(ModelProvider(catalog_provider, resolve)). catalog_provider is the models.dev namespace used by /login and /model; resolve returns the profile's extension.Upstream: its endpoint, the replay protocol it produces, a stream function over albedo's request types, and explain, which turns a provider failure into an actionable message. openai builds upstreams from the shared openai_api client with openai.upstream; a provider with another wire format supplies its own stream. Its extension should require the catalog or transport extension whose metadata and wire behavior it reuses. For example, openai declares the openai namespace, while codex also declares openai and inherits the shared transport through its dependency. New provider extensions get catalog-backed discovery by declaring their namespace; they do not implement provider /models calls.