From c82fdf81d61f72e65f30c8ce0fbb105b4a7166f0 Mon Sep 17 00:00:00 2001
From: Bryan Helmkamp <bryan@brynary.com>
Date: Sat, 7 Mar 2026 03:46:58 -0500
Subject: [PATCH] Add gpt-5.3-codex-spark to model catalog

OpenAI's Codex Spark is a smaller, faster codex derivative on Cerebras
hardware (1000 tok/s, 128K context, text-only, no pricing yet).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 crates/arc-llm/src/catalog.json | 14 ++++++++++++++
 crates/arc-llm/src/catalog.rs   | 25 ++++++++++++++++++++++++-
 docs/core-concepts/models.mdx   |  1 +
 3 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/crates/arc-llm/src/catalog.json b/crates/arc-llm/src/catalog.json
index a6ed1ad64..81b47d986 100644
--- a/crates/arc-llm/src/catalog.json
+++ b/crates/arc-llm/src/catalog.json
@@ -112,6 +112,20 @@
     "estimated_output_tps": 100,
     "aliases": ["codex"]
   },
+  {
+    "id": "gpt-5.3-codex-spark",
+    "provider": "openai",
+    "display_name": "GPT-5.3 Codex Spark",
+    "context_window": 131072,
+    "max_output": 128000,
+    "supports_tools": true,
+    "supports_vision": false,
+    "supports_reasoning": true,
+    "input_cost_per_million": null,
+    "output_cost_per_million": null,
+    "estimated_output_tps": 1000,
+    "aliases": ["codex-spark"]
+  },
   {
     "id": "gpt-5.4",
     "provider": "openai",
diff --git a/crates/arc-llm/src/catalog.rs b/crates/arc-llm/src/catalog.rs
index fb57debf2..2eaf08a68 100644
--- a/crates/arc-llm/src/catalog.rs
+++ b/crates/arc-llm/src/catalog.rs
@@ -239,7 +239,7 @@ mod tests {
         assert!(anthropic.iter().all(|m| m.provider == "anthropic"));
 
         let openai = list_models(Some("openai"));
-        assert_eq!(openai.len(), 6);
+        assert_eq!(openai.len(), 7);
 
         let gemini = list_models(Some("gemini"));
         assert_eq!(gemini.len(), 3);
@@ -346,6 +346,29 @@ mod tests {
         assert_eq!(get_model_info("gpt54").unwrap().id, "gpt-5.4");
     }
 
+    #[test]
+    fn gpt_5_3_codex_spark_in_catalog() {
+        let m = get_model_info("gpt-5.3-codex-spark").unwrap();
+        assert_eq!(m.provider, "openai");
+        assert_eq!(m.display_name, "GPT-5.3 Codex Spark");
+        assert_eq!(m.context_window, 131072);
+        assert_eq!(m.max_output, Some(128000));
+        assert!(m.supports_tools);
+        assert!(!m.supports_vision);
+        assert!(m.supports_reasoning);
+        assert_eq!(m.input_cost_per_million, None);
+        assert_eq!(m.output_cost_per_million, None);
+        assert_eq!(m.estimated_output_tps, Some(1000.0));
+    }
+
+    #[test]
+    fn codex_spark_alias() {
+        assert_eq!(
+            get_model_info("codex-spark").unwrap().id,
+            "gpt-5.3-codex-spark"
+        );
+    }
+
     #[test]
     fn closest_model_opus_to_gemini() {
         let opus = get_model_info("claude-opus-4-6").unwrap();
diff --git a/docs/core-concepts/models.mdx b/docs/core-concepts/models.mdx
index adf7e553a..85c380188 100644
--- a/docs/core-concepts/models.mdx
+++ b/docs/core-concepts/models.mdx
@@ -20,6 +20,7 @@ No single model is best at everything. Arc lets you assign the right model to ea
 | `gpt-5-mini` | openai | `gpt5-mini` | 1M | $0.20 / $2.00 | 70 tok/s |
 | `gpt-5.2-codex` | openai | | 1M | $1.80 / $14.00 | 100 tok/s |
 | `gpt-5.3-codex` | openai | `codex` | 1M | $1.80 / $14.00 | 100 tok/s |
+| `gpt-5.3-codex-spark` | openai | `codex-spark` | 128K | n/a | 1000 tok/s |
 | `gpt-5.4` | openai | `gpt54` | 1M | $2.50 / $15.00 | 70 tok/s |
 | `gpt-5.4-pro` | openai | `gpt54-pro` | 1M | $30.00 / $180.00 | 20 tok/s |
 | `gemini-3.1-pro-preview` | gemini | `gemini-pro` | 1M | $2.00 / $12.00 | 85 tok/s |