@anierbeck/pi-model-dynamic-router

Pi extension that routes model groups to concrete models. Balances intelligence, cost, and availability.

Packages

Package details

extension

Install @anierbeck/pi-model-dynamic-router from npm and Pi will load the resources declared by the package manifest.

$ pi install npm:@anierbeck/pi-model-dynamic-router
Package
@anierbeck/pi-model-dynamic-router
Version
1.6.1
Published
Oct 4, 2026
Downloads
990/mo · 222/wk
Author
anierbeck
License
MIT
Types
extension
Size
695.9 KB
Dependencies
0 dependencies · 4 peers
Pi manifest JSON
{
  "extensions": [
    "./dist/index.js"
  ]
}

Security note

Pi packages can execute code and influence agent behavior. Review the source before installing third-party packages.

README

pi-model-dynamic-router

Pi extension that routes model group names to concrete provider/model pairs. Auto-discovers models and pricing. Balances intelligence (GDPval), cost, and availability.

Fork of a-canary/pi-model-router — adds content-based dynamic routing (prompt classification → model group) on top of the upstream's price/quality/availability routing.

What You Get

  • Content-aware routing — every prompt is classified (trivial one-liner up to architecture review) and routed to a matching model tier: free models for daily coding, top-tier models reserved for design and planning work.
  • Automatic discovery & pricing — the router scans local daemons (Ollama, LM Studio) and cloud catalogs, and scrapes Artificial Analysis benchmark scores (GDPval plus per-task capability columns: AA-Briefcase Elo for planning work, SciCode/Terminal-Bench for coding).
  • Cost & quota balancing — flat-fee subscription models carry the daily load so expensive top-tier models stay available; quality-equivalence windows pick the cheapest model that is just as good.
  • Failover everywhere — model backoff, provider cooldowns, cascading fallback groups, and mid-stream retries are all transparent: the session just continues on the next best model.

Quick Start

pi install npm:@anierbeck/pi-model-dynamic-router
# Development checkout instead:
ln -s ~/pi-model-dynamic-router ~/.pi/agent/extensions/pi-model-dynamic-router
  1. Add a provider key — keys live with Pi, not with the router (see Adding a Provider).
  2. Run /reload in pi — the router discovers models, prices, and quality scores automatically.
  3. Switch your session to a group: scout, operational, tactical, strategic, planning, or dynamic (content-classified per prompt).

The shipped defaults need no configuration. To personalize, see Personalized configuration below — or jump straight to How It Works.

Personalized configuration

Users can override the embedded defaults without editing extension files:

  • Global: ~/.pi/agent/router-config.user.json
  • Project-local: <project>/.pi/router-config.json

Supports exclude rules (no paid OpenRouter models, no Fable, etc.). See docs/config-override.md for details.

How It Works

Dynamic Routing

The dynamic routing feature automatically classifies user prompts and selects the optimal model group based on the task type. It uses a classifier chain (cloud-first with classifier_cloud_fallback: true, Ollama mistral-nemo:latest primary / gemma2:2b fallback as the local last resort) and routes by the CATEGORY_TO_GROUP table in src/content-classifier.ts: trivial/exploration → scout, simple/standard → operational, code_simple → simple, code_complex/fallback → tactical, and design/planning → planning (top tier only).

Categories for Classification

The system classifies prompts into the following categories (see CATEGORY_TO_GROUP in src/content-classifier.ts for the authoritative mapping):

  • trivial: Greetings, one-liners, questions about the router itself
  • simple: Simple conversational requests
  • standard: Everyday tasks with no special shape
  • code_simple: Simple code changes (1-10 lines, syntax fixes, typos)
  • code_complex: Complex code changes (refactoring, debugging, >50 lines)
  • design: Architecture, system design, API design
  • planning: Project planning, roadmaps, task breakdown
  • exploration: Research, unclear requirements, brainstorming
  • fallback: Unclear or multiple categories apply

Mapping of Categories to Model Groups

Each category maps to a specific model group (CATEGORY_TO_GROUP, src/content-classifier.ts). Two tier-routing mechanisms (ADR-0023) keep the tiers meaningful despite GDPval compression at the top of the score range: a per-group max_gdpval cap (the shipped tactical is capped at 1700, so the flat-fee Mistral tank — glm-5-3 at 1644 — carries the daily code_complex load, while Claude's top models stay in strategic), and a best_quality_window (default 5%): inside a best-method group, candidates within the window of the best score are treated as equally good — cheapest first, cost ties to the lower score (in strategic, claude-sonnet-5-5 beats claude-opus-5-5 at equal subscription cost). On Mistral-quota days, tactical escalates through its fallback_groups into strategic, so Claude takes over automatically. Since the AA multi-benchmark round, a group can additionally rank its pool task-type-aware via score_by (ADR-0023 round 2): the same Artificial Analysis scrape that yields GDPval also carries the per-benchmark columns, so planning ranks by AA-Briefcase Elo and tactical by the SciCode/Terminal-Bench coding blend — floors and caps stay on GDPval, and a missing column falls back to GDPval ordering.

Category Model Group Use Case
trivial scout Greetings, one-liners — any free model
simple operational Simple conversational requests
standard operational Everyday tasks (GDPval ≥ 300)
code_simple simple Simple coding tasks (GDPval ≥ 300, free models only)
code_complex tactical Complex coding tasks (GDPval ≥ 600, capped at 1700 — the free-tank tier)
design planning High-stakes design decisions — top tier only (GDPval ≥ 1700)
planning planning Project planning and architecture — top tier only (GDPval ≥ 1700)
exploration scout Research and exploration — any model, cheap
fallback tactical Uncertain classification — a decent model, not a free one

Dynamic Group

The dynamic group is a special group that classifies each prompt in real-time (cloud chain first, Ollama as last resort: mistral-nemo:latest primary, gemma2:2b fallback) and automatically routes to the most appropriate model group via the CATEGORY_TO_GROUP table — scout, operational, simple, or tactical (strategic is not a classification target; planning is — design/planning prompts route to the top-tier-only planning group, never to the free-tank tactical tier). This enables context-aware model selection without manual intervention.

Requirements for Dynamic Routing:

To use the dynamic group, you need:

  • Ollama installed and running locally (ollama serve)
  • mistral-nemo:latest pulled for best classification quality (ollama pull mistral-nemo:latest)
  • gemma2:2b pulled as fallback (ollama pull gemma2:2b) — used automatically if mistral-nemo:latest fails
  • Ollama accessible from your system (default: http://localhost:11434)

Cloud-first (2026-09-27): with classifier_cloud_fallback: true (set on the shipped dynamic group) the classifier tries a chain of free cloud models FIRST — pinned classifier_cloud_model → scan-time probe-verified list → tiered discovery → configured free models — and treats Ollama as the last resort (see Data handling & privacy). If every cloud candidate fails and Ollama is unavailable, the classifier falls back to static keyword-based classification (only if allowStaticFallback is enabled) — otherwise the category fallback is returned.


Cascading Fallback & Intelligent Routing

The router implements a multi-layer fallback system that automatically recovers from model failures, rate limits, and unavailability.

How it works

When a model fails (API error, rate limit, empty response, or usage limit exceeded), the router:

  1. Tries the next model in the same group
  2. If all models in the group fail → cascades to fallback groups in this order:
    strategic → tactical → operational → scout → fallback
  3. Continues until a working model is found

Example: You select dynamic group, but the first model hits a rate limit → router automatically tries the next dynamic model → if all fail, tries strategic → then tactical → etc.

Configuration

Each group can define its fallback chain in router-config.json:

{
  "strategic": {
    "description": "Best models by GDPval",
    "method": "best",
    "models": ["anthropic/claude-3-sonnet", "mistral/mistral-medium-3.5"],
    "fallback_groups": ["tactical", "operational", "scout", "fallback"]
  }
}

Note: The dynamic group automatically inherits the full cascade chain.


Group-Based Cost/Quality Routing

The router encodes cost-quality tradeoffs directly in model groups rather than a separate tier overlay. Each group's min_gdpval and max_cost settings act as the cost tier: trivial/simple use max_cost: 0 (free models only), scout/fallback use min_gdpval: 0 (anything), tactical/strategic raise the GDPval floor to 600/700. A classified prompt maps to a group via CATEGORY_TO_GROUP (content-classifier.ts), and the group's own filters do the rest.

A group may also set min_context_length to require a minimum model context window (in tokens). Models whose scanned context window is unknown or below the threshold are dropped — strict, like min_gdpval. This lets a use-case-specific group (e.g. bulk_reader) guarantee its cheap models can actually hold the large inputs the use case demands, instead of falling back to the smallest free model that would truncate.

Historical note: an earlier separate "Cost Tier System" (free/budget/premium buckets, src/cost-tiers.ts) existed as a second filter layer on top of groups, but was removed — it was redundant with the group thresholds and conflicted with local models and the fallback cascade (see git history, commit that removed it: "remove cost-tier overlay from dynamic routing").


Model Momentum

After context compaction (when >30% of tokens are removed or >5 messages/500 tokens are dropped), the router reuses the previous model for the next turn.

Why?

  • Consistency: Maintains the same model's "thinking style" after major context changes
  • Efficiency: Avoids unnecessary model switching
  • Stability: Reduces variation in responses during long conversations

Detection

Compaction is automatically detected when:

  • Token count drops by >30% compared to previous turn
  • More than 5 messages are removed
  • More than 500 tokens are removed

Note: Model momentum only forces reuse during compaction. For similar tasks, it provides a hint to the classifier.


Status Line Integration

The router now synchronizes with Pi's status line to display the actually active model (not failed candidates).

Behavior

  • Status line updates as soon as a model's stream is established (before the first token)
  • Only shows models that successfully started streaming
  • Failed candidates (API errors, rate limits) never appear in the status line
  • After successful completion, the model remains displayed until the next turn

Example

# Before (incorrect):
scout/dynamic→claude-bridge/claude-fable-5  # ← Failed, but shown!

# After (correct):
scout/dynamic→mistral/mistral-medium-3.5   # ← Actually active model

This provides accurate feedback about which model is currently generating responses.


Auto-Discovery

On startup, the router automatically:

  1. Resolves nothing credential-related itself (ADR-0022). The router never reads or writes Pi's credential store — Pi resolves API keys (auth.json incl. ! secret-manager commands, models.json, env, CLI OAuth) via modelRegistry.getApiKeyForProvider whenever a router-internal path needs one (free-model registration, free-cloud fallback). If a key lives in a pass store or a shell command, reference it from Pi's own auth.json and Pi executes it.
  2. Scans local models (Ollama / LM Studio) and OpenRouter's public pricing catalog; cloud model inventory comes from Pi's catalog (ADR-0021 — the router registers no scan-discovered cloud models)
  3. Scrapes GDPval scores from Artificial Analysis with hardcoded fallbacks — a plain, unauthenticated GET of a public leaderboard page; no local data is sent
  4. Caches pricing per provider/model from OpenRouter's public pricing endpoint

All scanning is async and non-blocking.

Data handling & privacy

  • The router never reads or writes Pi's credential store (ADR-0022). No API key, key reference, or auth-file pointer is stored in router-config.json or resolved by the router — Pi owns credential resolution end-to-end. (Legacy keys arrays in older router-config files are ignored, never read.)
  • Prompt content stays local by default. The dynamic-group content classifier runs against a local Ollama model. If both local classifier models are unavailable, it falls back to static keyword matching (only if allowStaticFallback is enabled) rather than sending anything externally.
  • Optional cloud classifier fallback (classifier_cloud_fallback, off by default). If explicitly enabled in router-config.json, and only as a last resort when local classification fails, the raw prompt is sent to a free cloud model from your own configured free_models for classification purposes. This is opt-in and separate from using that same provider as a normal answering fallback, because classification and answering have different data-exposure implications for the same free-model config. Enable only if you're comfortable with that provider seeing prompt content for classification, not just for answering your requests.
  • GDPval scraping and pricing/model scans are outbound-only, read-only HTTP GETs to public model/leaderboard endpoints; no prompt content, API keys, or other local data is included in those requests.

Group Selection

Each group auto-discovers available models, filters by quality, and selects by billing preference. The shipped groups (see router-config.json):

Group Method Quality gate Ranks within the pool by Use for
strategic best GDPval ≥ 700 GDPval (quality window) Critical decisions
planning best GDPval ≥ 1700 AA-Briefcase Elo (score_by) Design & architecture — top tier only
tactical best 600 ≤ GDPval ≤ 1700 SciCode/Terminal-Bench blend (score_by) Daily coding — the free-tank tier
operational tiered GDPval ≥ 300 billing preference Everyday tasks
scout tiered GDPval ≥ 0 billing preference Exploration, cheap work
fallback tiered GDPval ≥ 0 billing preference Last resort
dynamic dynamic — — Auto-classifies each prompt and routes to the best group

No curated model lists. Groups draw from all discovered models automatically. Quality gates (min_gdpval/max_gdpval) always use GDPval — a score_by column only orders the models within an admitted pool.

GDPval

GDPval is a composite quality score from Artificial Analysis that combines intelligence, throughput, and cost-efficiency into a single number. Higher = better overall value. The router scrapes scores once on first run and caches them; subsequent startups use the cache. Use /router scan to force a refresh. Hardcoded fallbacks from gdpval_builtin in the config are always loaded as a baseline.

Price Routing — how tiered works

  1. Filter — discard any model below the group's GDPval percentile threshold.
  2. Sort — rank survivors by billing tier first, then by effective cost within each tier:
    • Tier 0: free models
    • Tier 1: subscription (lowest rate-limit pressure first, then cost)
    • Tier 2: local (Ollama / LM Studio)
    • Tier 3: pay-per-token (ascending effective cost)
  3. Select — pick the top-ranked model (cheapest within the preferred billing tier that clears the quality floor).

This means operational picks the cheapest model that clears its GDPval floor, while strategic ranks by best (highest score, quality window applied) regardless of cost.

costMux

After 4 consecutive HTTP 429s from a provider, the router applies a permanent cost multiplier penalty (costMux) to all its models. This pushes the provider to the back of the sorted list without blocking it entirely — useful when a provider is temporarily overloaded but still reachable. The penalty persists for the session and is reset on /router reload.


Rate Limits & Failover

On HTTP 429 the router works through two escalating responses:

  1. Model backoff — the model enters exponential backoff (1 min → 2 → 4 → ... → 90 min cap) and the group falls over to its next-ranked candidate for the current request. (ADR-0022 removed multi-key rotation — with keys owned and resolved by Pi there is exactly one key per provider.)
  2. costMux penalty — after 4 consecutive 429s, the provider receives a permanent cost multiplier for the session (see costMux above), demoting all its models in future selections.

Both mechanisms are transparent to the user — the session continues with the next available model.

Rate Limit & Subscription Handling

The router automatically handles rate limits, usage limits, and subscription errors from all providers, including third-party extensions like claude-bridge.

Supported Error Patterns
Error Type Detection Behavior
Rate Limit (429) HTTP 429 response Soft failure → try next model
Usage Limit Exceeded "out of usage credits", "rate limit hit" Soft failure → try next model
API Provider Not Found "No API provider registered" Soft failure → try next model
Empty Response No tokens within timeout Soft failure → try next model
Hard API Error Connection refused, timeout Soft failure → try next model
Example: Claude Subscription Limits

If you hit your Claude subscription limit:

Warning: [rate-limit] Claude unknown rate limit hit — resets unknown
You're out of usage credits. Run /usage-credits to keep using Fable 5

The router will:

  1. Detect the "out of usage credits" message
  2. Treat it as a soft failure (not a hard error)
  3. Automatically try the next model in the group
  4. If all models in the group fail → cascade to fallback groups
Important Notes
  • Claude-bridge: Different subscription tiers have different model access:
    • Pro: Claude 3.5 Sonnet, Haiku
    • Max: All models including Fable 5, Opus 5
  • The router cannot know your subscription tier — it tries models and falls back on errors
  • This is intentional: It allows graceful degradation when limits are hit
Best Practices
  1. Order models by preference in your groups (most preferred first)
  2. Include fallback models from different providers
  3. Use cascading fallback groups for maximum reliability
  4. Check /usage-credits if you consistently hit limits

Example configuration for reliability:

{
  "strategic": {
    "models": [
      "claude-bridge/claude-opus-5",    // First choice (Max only)
      "claude-bridge/claude-sonnet-5",  // Fallback (Pro/Max)
      "anthropic/claude-3-5-sonnet",    // Cloud fallback
      "mistral/mistral-medium-3.5"     // Final fallback
    ],
    "fallback_groups": ["tactical", "operational", "scout", "fallback"]
  }
}

This ensures automatic recovery when subscription limits are hit.


Stream Retry

When a streaming response fails mid-stream (empty body, connection drop, timeout), the group automatically retries with the next ranked candidate without requiring the user to resend the prompt. Soft failures are distinguished from hard errors: a 4xx response is not retried, but an interrupted stream or empty response is.


Delegating subtasks to cheap groups (Pi subagents)

The router only resolves a group name to the best available model for a single completion request — it has no concept of "split this task into subtasks and run the cheap ones on a cheap model." That kind of decomposition belongs one layer up, in Pi's subagent system, which can already address any configured group directly by model ref: every group is registered as its own provider, so <group>/<group> (e.g. trivial/trivial, scout/scout, strategic/strategic) is a valid model value for subagent(...) calls, exactly like any other provider/model pair Pi knows about.

This lets you fan out I/O-heavy work (reading/summarizing several files) to a cheap group in parallel, then run one expensive-group call over the collected results — without any router code changes:

subagent({
  workflowScript: `
    const files = ["src/a.ts", "src/b.ts", "src/c.ts"];
    const summaries = await runs.all(files.map((f) => ({
      key: f,
      agent: "scout",
      model: "trivial/trivial",
      task: "Summarize the public API of " + f,
    })));
    const combined = summaries.map((s) => s.output).join("\\n\\n");
    return runs.run("synthesize", {
      agent: "worker",
      model: "strategic/strategic",
      task: "Given these file summaries, propose a refactor:\\n\\n" + combined,
    });
  `,
});

The bulk_reader group adds a min_context_length floor so the cheap model it resolves to is guaranteed to hold several files at once — exactly the property a trivial/scout group does not guarantee:

subagent({
  workflowScript: `
    const files = ["src/a.ts", "src/b.ts", "src/c.ts", "src/d.ts"];
    const summaries = await runs.all(files.map((f) => ({
      key: f,
      agent: "scout",
      model: "bulk_reader/bulk_reader",
      task: "Read " + f + " and return a bullet list of its public API.",
    })));
    return runs.run("synthesize", {
      agent: "worker",
      model: "strategic/strategic",
      task: "Given these file summaries, propose a refactor:\\n\\n" +
        summaries.map((s) => s.output).join("\\n\\n"),
    });
  `,
});

code_writer/code_writer is the symmetric counterpart: a cheap group with enough context for a spec + one reference file, used to generate boilerplate the expensive model never has to read back as output tokens.

See docs/adr/0007-task-decomposition-and-delegation.md for why this lives in the subagent layer rather than in the router.

Configuration

Main Configuration File

router-config.json:

{
  "providers": {
    "openrouter": {
      "billing": "pay_per_token",
      "free_models": [
        "openrouter/qwen/qwen3-4b:free",
        "openrouter/openai/gpt-4o-mini:free"
      ]
    }
  },
  "model_groups": {
    "strategic": { "method": "best" },
    "tactical": { "method": "tiered", "min_gdpval_pct": 75 },
    "scout": { "method": "tiered", "min_gdpval_pct": 25 }
  },
  "model_metrics": {
    "claude-bridge/claude-sonnet-5": { "cost_per_m": 0.0000015 }
  },
  "gdpval_builtin": {
    "mistral-medium-3-5": 933,
    "claude-sonnet-5": 1603,
    "qwen3-8-27b": 580
  }
}

Billing Preference (per-group tier override)

By default, method: "tiered" sorts by billing tier first: free → subscription → local → payg. This means already-paid subscription models (e.g. Mistral) always rank ahead of local compute (Ollama), even in scout where local models conceptually belong on top.

billing_preference re-ranks a group by billing tier after its method has ordered the candidates. It does not change which models passed the filters — only their order. Five values:

Value Ordering Use for
"default" (or omitted) free → subscription → local → payg Groups where an already-paid subscription model is the cheaper choice in time/quota terms.
"cloud_first" cloud (free → subscription) ahead of local Groups that should prefer cloud models — the local daemon is a fallback, not the default (scout / bulk_reader / code_writer).
"local_first" free → local → subscription → payg Groups where local models should rank ahead of subscription, but genuinely-free remote models still win.
"local_before_payg" free → subscription → local → payg Cheap groups (trivial / simple): free and subscription first, local ahead of pay-as-you-go only.
"strict_local" local → free → subscription → payg Groups where the local daemon should answer first, ahead of even the $0 remote models. Not used by the shipped config (a guard test forbids it there).

payg is always last. This is opt-in per group — other groups keep the default ordering. The shipped config pins: trivial/simple → local_before_payg, scout/bulk_reader/code_writer → cloud_first.

A subscription model's $0 cost is not free. Flat-rate plans like pi-claude hide a hard time/token limit, so a trivial prompt routed there is the single most expensive thing the router can do. Prefer a local model or a genuine :free model for cheap work.

Agent-capability filter (non_agent_model_prefixes)

Models whose ref starts with one of these prefixes are excluded from all routing groups (they remain selectable as plain chat models). GDPval scores capability, not agent-reliability — raw chat/completion/audio families (e.g. voxtral-, ministral-) must never win a routing slot over an agent-capable model, whatever their benchmark score. The shipped default:

"non_agent_model_prefixes": [
  "mistral-small-",
  "magistral-small-",
  "ministral-",
  "voxtral-",
  "codestral-"
]

Replace the array in any config layer to change the filter.

"scout": {
  "method": "tiered",
  "billing_preference": "cloud_first",
  "min_gdpval": 0
},
"trivial": {
  "method": "tiered",
  "billing_preference": "local_before_payg",
  "min_gdpval": 0
}

Read Delegation (bulk reads)

Delegation has two halves. A large read/bash result is replaced by a summary produced by a cheap bulk_reader group, and a full-file read is blocked before it runs and redirected to a targeted offset/limit read. Both are off by default.

"delegation": {
  "enabled": true,
  "group": "bulk_reader",
  "tools": ["read", "bash"],
  "min_chars": 3500,
  "max_raw_chars": 60000,
  "block_lines": 350,
  "expensive_groups": ["strategic", "tactical"],
  "expensive_providers": []
}
Key Default Meaning
enabled false Master switch. Anything other than true is off (fail-open).
group "bulk_reader" Model group that produces the summary. Must be registered as a group so the router intercepts it.
tools ["read", "bash"] Result-bearing tools to delegate. Trusted as a whole: a non-array, or any non-string/empty entry, discards the entire list and uses the default.
min_chars 3500 Minimum result size before delegating. Below this, delegation latency exceeds the savings.
max_raw_chars 60000 Cap on result text sent to the sub-call.
block_lines 350 Pre-call block for full-file reads. 0 disables pre-call blocking explicitly; negative or non-numeric falls back to the default.
expensive_groups ["strategic", "tactical"] Groups whose models may not do full-file reads. Matched against the active config's materialized model lists.
expensive_providers [] Provider prefixes whose models count as expensive regardless of group — e.g. ["pi-claude"] matches pi-claude/claude-sonnet-5.

Targeted reads (any read with offset or limit) and piped/grep'd bash commands are always delegated around — they are precise extracts the orchestrator needs verbatim, and the pre-call block never fires for them.

Group and provider lists are trusted as a whole, like tools: a partially-valid list would silently block or delegate the wrong models, so an invalid list falls back to the default and an empty list ([]) genuinely disables the check. A config whose model_groups have no materialized models arrays (static-only) matches nothing on expensive_groups — the size threshold still protects on its own.

The expensive-model pre-call block judges the caller by the driving model of the turn — the first model that streamed — not by whatever model streamed most recently. A nested bulk_reader sub-call mid-turn does not un-block the expensive model's subsequent reads.

Provider Configuration

Provider registration is conservative (never overwrites): the router only registers a provider with Pi when Pi does not know it yet — i.e. when modelRegistry.find(provider, modelId) returns nothing for every model of that provider. This protects models.json entries (with compat flags), extension-provided providers, and Pi-native providers from being clobbered. If Pi already knows the provider from any source, the router does not touch the registration.

Real per-model capabilities (not hardcoded): when the router does register a provider, it uses the real capabilities the scan captured from the provider's /v1/models (Mistral capabilities.vision/reasoning/max_context_length, OpenRouter architecture.input_modalities/context_length) — never a hardcoded reasoning: true / input: ['text','image'] blanket. Unknown fields fall back to conservative defaults (vision: false unless confirmed, reasoning: false unless confirmed), so a model is never falsely advertised as vision-capable (which caused 422 errors for GLM-5-2).

Ollama is setup-independent: the router scrapes Ollama's /api/show per model to get the real context length (model_info.*.context_length) and capabilities, and registers Ollama with providerOptions.num_ctx set to that real value — so prompts >32K don't get truncated. This works for every user, with or without any specific Ollama extension. The router only registers Ollama when Pi doesn't know it; if another extension or models.json already registered Ollama, the router doesn't overwrite.

Per-provider model filter (optional, generic): a PROVIDER_MAP entry may set modelFilter: "<regex>" to constrain which scanned model ids are kept. Generic and user-configurable — not a hardcoded special case. Useful when a key sees a broad catalog (e.g. a provider key that returns all of a vendor's models when the provider is meant for a subset).

New Configuration Options

Option Purpose Example
fallback_groups Define cascade chain for fallback ["tactical", "operational", "scout"]
cost_per_m Cost per million tokens (for estimates) 0.0000015
model_metrics Per-model cost overrides { "claude-bridge/claude-sonnet-5": { "cost_per_m": 0.0000015 } }
gdpval_builtin GDPval overrides for new models (keyed by slug) { "mistral-medium-3-5": 933, "qwen3-8-27b": 580 }
billing_preference Per-group tier ordering override ("local_first" / "strict_local" rank local models ahead of subscription) "local_first"
modelFilter (PROVIDER_MAP) Regex to constrain scanned model ids per provider "^(zai-)?glm"

Groups need no models arrays — everything is auto-discovered plus any explicitly listed models.

Adding a Provider

The router has no credential storage of its own (ADR-0022): API keys live exclusively with Pi, and Pi resolves them whenever a request needs one. Adding a provider is therefore a single step — give the key to Pi:

  1. Store the key where Pi looks for it — any one of:
    • pi auth <provider> (Pi's built-in auth)
    • an environment variable (ANTHROPIC_API_KEY, OPENAI_API_KEY, …)
    • an entry in Pi's auth.json — including a !-prefixed secret-manager command (e.g. !pass show api/openrouter); Pi executes it
    • CLI OAuth for CLI-auth providers (qwen auth login, gemini auth login)
  2. Restart pi — the router picks up everything Pi knows, scans local daemons and cloud catalogs, and the provider's models start competing in your groups automatically.

For a non-standard base URL or model list, configure the provider in Pi's models.json — the router never overwrites an existing Pi registration (see Provider Configuration below).

There is a guided walkthrough in the shipped skill: /skill:router-login (same steps, with connectivity checks and troubleshooting).

Supported Providers

26 known providers (the router's PROVIDER_MAP, below) — plus any extension-registered provider (e.g. claude-bridge), which the router discovers automatically.

Provider Type Registration Notes
anthropic Built-in Pi Token-based (via claude-bridge extension for subscription)
openai Built-in Pi Standard OpenAI
google Built-in Pi Google AI
mistral Built-in Pi Mistral Cloud
openrouter Router Router Free tier models available
ollama Extension Extension Local models
lm-studio Extension Extension Local models
claude-bridge Extension Extension Claude subscription via local proxy
qwen-cli Extension Extension Qwen CLI
gemini-cli Extension Extension Google Gemini CLI
antigravity Extension Extension -
chutes Router Router Free tier models available
mistral-zai Router Router Mistral via Z.AI
groq Router Router Fast inference, free tier
cerebras Router Router Fast inference
xai Router Router xAI (Grok)
zai Router Router Z.AI
huggingface Router Router -
kimi-coding Router Router -
minimax Router Router -
minimax-cn Router Router -
opencode Router Router -
opencode-go Router Router -
vercel-ai-gateway Router Router -
azure-openai Router Router -
deepseek Router Router -
github-copilot Router Router Subscription

Claude-bridge Support:

  • Important: Claude-bridge is a separate Pi extension that must be installed to use Claude models with a subscription.
  • How it works: The extension registers claude-bridge/* models with Pi. The router discovers and uses them automatically.
  • Model availability depends on your Claude subscription plan (Pro, Max, etc.).
  • No double registration: The router does not register claude-bridge providers itself — it only uses models already registered by the extension.

Commands

Command Description
/router Overview: providers, groups, selections, rate limits
/router <group> Detailed view of a group with ranked candidates
/router scan Re-scan models and GDPval scores
/router cost Audit-depth cost report: per-model, per-window usage from the router's own token accounting
/router errors [n] Last n session errors (default 15, max 50) with status-line correlation
/router cooldowns [clear] Active rate-limit cooldowns (ref, remaining, hits); clear also resets model-health streaks
/router blocklist Models blocked after a permanent provider failure (reason, since, re-probe time)
/router blocklist clear [ref] Unblock one model, or all (e.g. after fixing an API key)
/router reload Hot-reload config and cache

Logging

The router logs to ~/.pi/logs/router.log (mirrored to <project>/.pi/logs/router.log). Each file rotates at 20 MB into router.log.1 … router.log.4; older data is dropped.

Log levels, from quiet to verbose: "error" (hard failures only) → "warn" (adds operational problems: rate limits, failed models, fallbacks, wedges) → "info" (adds routine narration and the per-prompt routing trace) → "debug" (adds [diag] lines). Set "log_level" in ~/.pi/agent/router-config.user.json, or via ROUTER_LOG_LEVEL (overrides the config). The shipped default is "warn" (release builds must not be verbose); local dev typically sets "info" or "debug". The recurring "tryStream skipped" line is written once per model until its reason changes.

KPI audit

npm run audit:kpi -- [--since 7d|24h|<ISO date>] [--log <path>] [--json] summarizes ~/.pi/logs/router.log: delegation savings and failures, blocked full-file reads, failed hops by reason and model, total failovers, learned blocklist entries, watchdog wedge events and classifier health.

Tools

Tool Purpose
set_model_from_group Switch session to best model from a group
resolve_model_group Preview what a group would resolve to
update_model_metrics Manual metric override
bulk_read Answer a question about files via a cheap reader model, without loading their content into the session context

The dynamic group has no dedicated tools — classification runs automatically inside the group's resolve path (src/content-classifier.ts).

Footer

strategic/anthropic/claude-opus-4-6 | int:1450 tps:80 | 12k/8k $1.43 62% | ⏱14m | ⌂ proj | ⎇ main | ⛔2 | ⚠1 err

The ⚠N err part counts the session's recorded stream failures — the same entries /router errors lists in full.

Internals

How the code is organized — relevant if you work on the router itself, not needed to use it.

The router uses a modular architecture with the following components:

Module Purpose Key Features
providers.ts Provider definitions and mappings 26 supported providers, authentication patterns
types.ts Type definitions Config, Cache, Metrics, RateLimit, Group, Provider types
utils.ts Utility functions String manipulation, reference parsing
rate-limit.ts Rate limit management Backoff cooldowns, cost multiplier
discovery.ts Discovery management Free-model inventory (ADR-0022: key discovery removed — Pi owns credential resolution)
metrics.ts Metrics management GDPval, throughput, latency tracking
cache.ts Cache management Persistent caching, versioning
routing.ts Routing logic Model selection, filtering, sorting
stream-orchestrator.ts Stream orchestration groupStream/driveStream extraction from index.ts, buildOrchestratorContext factory with live getters for router/rateLimitManager/cacheManager
detection.ts Error event detection Rate-limit/abort/overflow text patterns, isRateLimitLikeReason(), isAbortLikeText(), parseResetAtMs()
content-classifier.ts Content classification mistral-nemo:latest primary, gemma2:2b fallback, cloud fallback via pi's modelRegistry.completeSimple() (see ADR 0004)
escalation.ts Session escalation Loop detection, level tracking, session-safe reset
model-matcher.ts LLM-assisted model matching Batched matching, plausibility guard, hallucination rejection
local-llm.ts Provider-agnostic LLM caller Ollama OR LM Studio, OpenRouter free cloud fallback
exclude.ts Personalized exclude rules Provider/pattern/paid-model filtering for all groups
config-loader.ts Layered configuration Deep-merge defaults → global → project-local overrides

index.ts wiring (2026-10 refactor): index.ts is now a thin extension entry point (~640 lines, down from ~3750): it owns the shared mutable state (the one cache object, cfg, managers), load()/loadCache(), and buildOrchestratorContext(). All behavior lives in createX(deps) factory modules that receive live getters (plus setters for write access) so reload-time swaps are always seen — never stale closure captures:

Factory module Owns
context-utils.ts context estimation, timeouts, compaction detection
limit-glue.ts metrics/rate-limit/cost glue functions
model-resolve-glue.ts resolve, detectGroup, fmtModel, getTopModels
scan-runner.ts scan() incl. GDPval scrape + LLM matching
dynamic-config-runner.ts generateDynamicConfigNow
free-model-registration.ts registerFreeModelOnDemand
stream-proxy.ts groupStream, tryStream, consumeWithDetection, local-stream limiter
group-registration.ts registerGroupProviders (Ü1 guard), registerGroupModels (merge-not-replace)
event-handlers.ts the core pi.on(...) handlers
tools.ts the four pi.registerTool registrations
commands.ts the /router command

The final session_shutdown handler and process-exit/signal cleanup stay at the bottom of index.ts (handler order is load-bearing). The router never calls pi.setModel() except in the set_model_from_group tool.

This modular design enables better maintainability, testing, and extensibility.

GDPval model matching pipeline

When a model needs a GDPval score, the router resolves it in three tiers:

  1. model-map.yaml (authoritative) — explicit model-id → slug mapping
  2. Token-set fallback (deterministic) — fuzzy token matching
  3. LLM-assisted matching (semantic) — a local LLM matches model ids to GDPval slugs, with cross-family and size-tier guards

See docs/architecture.md for details.

Development

npm install          # also wires the pre-push secret scan (core.hooksPath)
npm test             # vitest
npx tsc --noEmit     # type check
npm run secret-scan -- --range origin/main..HEAD   # manual range scan

main is protected: changes land through pull requests with the test and secret-scan checks green. The pre-push hook scans every pushed commit for credentials (gitleaks, brew install gitleaks) and for private references (scripts/forbidden-patterns.ts), because in a public repository a push is already a publication. See AGENTS.md §8.

License

MIT