github.com/replicate/cog

Breaking changes

• Local servers now bind to 127.0.0.1 instead of 0.0.0.0. cog serve, cog run -p, cog predict, and cog train no longer expose the prediction endpoint to your whole network by default. To get the old behavior back, use cog serve --host 0.0.0.0 or cog run -p 0.0.0.0:8888 — -p now accepts host:port. (#2812)

New features

• Browser playground. cog playground starts a local, schema-driven web UI for talking to a running model — a Postman-like tool that reads the model's OpenAPI schema and builds the input form for you, with a request inspector and webhook relay. Point it at anything speaking the Cog HTTP API with --target. (#3123)

• cog serve --playground. Serve the model and the playground in one command. The playground gets its own port (--playground-port, default 9000, 0 picks a free one) and both URLs are printed on startup. (#3154)

• @cog.concurrent decorator. Configure async runner concurrency on the method that does the work instead of in cog.yaml:

  class Runner(cog.BaseRunner):
      @cog.concurrent(max=4)
      async def run(self, prompt: str = cog.Input()) -> str:
          return await generate(prompt)

  The value is extracted statically at build time. concurrency.max in cog.yaml still works and still takes precedence, but it now warns on build — remove it when you migrate. (#3089)

• Input validation before build and run. cog predict, cog run, and cog train now validate -i inputs against the model's OpenAPI schema before building the image or starting the container, so a typo fails in a second rather than after a full build. Covers unknown input names, missing required inputs, type mismatches, enum values, numeric bounds, string length, and regex patterns. The schema is generated statically from cog.yaml; for existing images it's read from the openapi_schema label. (#3097)

• accept on Path and File inputs. Declare the MIME types or extensions an input takes — Input(accept="image/*"), Input(accept="audio/wav,audio/mp3"), Input(accept=".safetensors,.bin") — and Cog emits it as x-cog-accept in the OpenAPI schema so UIs and clients know what to offer. Using accept on a non-file type is a build error. (#2863)

• Local wheels and source archives in requirements. build.python_requirements now accepts bare local paths like ./dist/mylib-0.1.0-py3-none-any.whl or ./packages/localpkg.tar.gz. Paths resolve relative to the requirements file, and only the referenced artifacts get staged into the build. .whl, .zip, .tar.gz, .tgz, .tar.bz2, and .tar.xz are supported. (#3095)

Improvements

• Readable logs from local commands. cog serve, cog run, cog predict, and cog train now run the model with console-formatted logs instead of production JSON. Deployed models are unaffected. (#2806)
• Download progress for cog weights. cog weights import and cog weights pull show live Docker-style progress while they populate the local weight store. (#3087)
• Prebuilt base images are documented. New base images page covers what's on Cog's prebuilt base images, how --use-cog-base-image works, and how it interacts with --use-cuda-base-image. (#3088)

Bug fixes

• GPU builds on CUDA base images work again. Builds on nvidia/cuda images failed with externally-managed-environment because uv-managed Python is marked PEP 668 externally managed and uv 0.9.x enforces it. Cog now passes --break-system-packages wherever it installs into a uv-managed Python, not just in cog base-image. (#3073)
• Explicit cudnn with a CUDA minor version now validates. A config pairing cuda: "11.6" with cudnn: "8" was rejected up front even though 11.6 resolves fine to a patch-level base image like nvidia/cuda:11.6.2-cudnn8-devel-ubuntu20.04. Validation now matches versions the same way image selection does. (#3070)
• Install one-liners work on Linux arm64. uname -m reports aarch64 there, but the release asset is cog_Linux_arm64, so the documented curl command and tools/install.sh both 404'd. Both now normalize the architecture. (#3066)
• Generated OpenAPI schemas report the real Cog version. info.version was hard-coded to 0.1.0; it now carries the version that built the schema. (#3075)
• cog weights pull is quieter. Directory entries in weight tarballs no longer produce skipping unexpected tar entry lines. (#3076)

New features

• Server-Sent Event prediction streams. HTTP prediction requests can now ask for Accept: text/event-stream to receive start, output, log, metric, and terminal completed events for predictors that explicitly opt in with @streaming / @cog.streaming. Reconnecting clients can replay retained in-flight prediction events with PUT /predictions/{id}. (#3019)
• JSON-native union inputs. Cog now supports union-typed predictor inputs in generated schemas and HTTP request handling, allowing compatible JSON-native values to be resolved correctly. (#3048)

Improvements

• Example models now live in the Cog repository. The example models from replicate/cog-examples have moved into this repository under examples/, with updated run.py / BaseRunner examples for common workflows including images, training, notebooks, streaming, concurrency, context, and Replicate API usage. (#3055)
• Experimental warning for cog weights. Every cog weights subcommand now prints a warning that the weights workflow is experimental and should not be relied on in production workflows yet. (#3025)
• Static schema parser target resolution. The static Python schema parser now uses run() as the primary prediction entry point while preserving legacy predict() fallback behavior, and resolves inherited and imported targets more consistently. (#3027)

Bug fixes

• cog.Secret inputs now work with coglet-backed predictions. Predictors that annotate inputs as Secret, Optional[Secret], or Secret | None now receive cog.types.Secret values at runtime again, restoring behavior that regressed in the Rust/coglet runtime rewrite. (#3057)
• cog doctor --fix now shows available remediation text. Findings without an auto-fix now display their remediation message instead of incorrectly saying no auto-fix is available. (#3031)
• Cog-managed weight uploads now send the correct layer media type. Weight layer uploads now propagate the Cog weight media type during registry finalization while preserving regular image-layer behavior. (#3033)
• Predictor validation now handles PEP 563 string annotations. Predictor files using from __future__ import annotations no longer reject valid setup() -> None methods or accept invalid run() -> None methods because None annotations were stored as strings. (#3034)
• cog serve now mounts weights like cog run. Models served locally now receive configured weights consistently with local prediction runs. (#3044)
• Omitted optional inputs now resolve to None at the HTTP edge. Optional predictor inputs omitted from HTTP requests are now passed as None instead of being treated inconsistently by request handling. (#3051)

Changelog

• d6c2b70 Bump version to 0.21.0-rc.3 (#3050)
• 63c65df feat: support JSON-native union inputs (#3048)

Changelog

• a1b710a Bump version to 0.21.0-rc.2 (#3045)
• 9b9f310 chore: regen lockfile
• 8428257 ci: pin mise version in release workflows (#3046)
• 9075ab5 fix: mount weights in cog serve like cog run does (#3044)

New features

• Server-Sent Event prediction streams. HTTP prediction requests can now ask for Accept: text/event-stream to receive start, output, log, metric, and terminal completed events for predictors that explicitly opt in with @streaming / @cog.streaming. Reconnecting clients can replay retained in-flight prediction events with PUT /predictions/{id}. (#3019)

Improvements

• Experimental warning for cog weights. Every cog weights subcommand now prints a warning that the weights workflow is experimental and should not be relied on in production workflows yet. (#3025)
• Static schema parser target resolution. The static Python schema parser now uses run() as the primary prediction entry point while preserving legacy predict() fallback behavior, and resolves inherited and imported targets more consistently. (#3027)

Bug fixes

• cog doctor --fix now shows available remediation text. Findings without an auto-fix now display their remediation message instead of incorrectly saying no auto-fix is available. (#3031)
• Cog-managed weight uploads now send the correct layer media type. Weight layer uploads now propagate the Cog weight media type during registry finalization while preserving regular image-layer behavior. (#3033)
• Predictor validation now handles PEP 563 string annotations. Predictor files using from __future__ import annotations no longer reject valid setup() -> None methods or accept invalid run() -> None methods because None annotations were stored as strings. (#3034)

New features

• cog run command. The cog predict command has been renamed to cog run with full backward compatibility. cog predict still works as an alias. (#3015)
• Model refs for cog push and weights commands. You can now reference models by name (e.g., r8.im/user/model) instead of full image URLs when pushing or managing weights. (#3018)
• Multi-source weights and HTTPS weight sources. Weights can now be fetched from multiple sources, including direct HTTPS URLs. (#3008)
• Opaque annotations in schema generation. Predictor inputs can use the new Opaque annotation to exclude fields from the generated schema. (#3001)

Improvements

• Runtime schema generation fully removed. The legacy runtime Python schema generation path has been completely removed. Cog exclusively uses static schema generation, making builds faster and more reliable. (#3003)
• Centralized build state and cleaner Docker context. Cog now stores build state in a dedicated .cog/ directory that is automatically filtered from the Docker build context. (#3000)
• Support durable base-image build context. Base image builds now support a durable build context for better caching and reliability. (#3004)
• Support uv-managed Python installs in generated Dockerfiles. Generated Dockerfiles now properly handle Python installations managed by uv. (#2999)

Bug fixes

• Pushing a model with a version tag now emits a clean URL. The Replicate model URL printed after cog push no longer includes the image tag (e.g., :latest), preventing 404 errors when users click the link. (#3020)
• Prefer latest torch patch when resolving unpatched versions. When resolving PyTorch compatibility, Cog now correctly selects the latest available patch version for unpatched version specs. (#3009)
• Deterministic compatibility matrix output. Compatibility matrices are now sorted for consistent, deterministic output. (#3006)

Changelog

• 0780450 Bump version to 0.19.3 (#2995)
• cac3e91 feat: experimental managed weights (#2974)

Changelog

• 427d486 Bump version to 0.19.2 (#2984)
• d9c2b14 fix: cap fuzz test input size to prevent timeout (#2981)
• 4269575 fix: support typing_extensions TypedDict at runtime (#2983)

Bug fixes

• Support for TypedDict in schema generation. Fixed an issue where TypedDict type annotations would cause schema generation to fail. (#2978)
• Build order fix for resource exhaustion. Reordered coglet wheel build to run after cog/sdk builds to prevent resource exhaustion during release builds. (#2977)

Maintenance

• Removed dead Go code. Cleaned up unused code identified by deadcode analysis. (#2979)
• Removed accidentally committed folder. Deleted a folder that shouldn't have been in the repository. (#2972)
• CI lockfile improvements. Switched to strict lockfile mode and regenerated mise.lock. (#2975)

Dependencies

• Updated golang.org/x/crypto from 0.49.0 to 0.50.0 (#2965)
• Updated golang.org/x/term from 0.41.0 to 0.42.0 (#2933)
• Updated google.golang.org/grpc from 1.79.3 to 1.80.0 (#2967)
• Updated rand from 0.8.5 to 0.8.6 in /crates (#2958)

New features

• cog doctor command. Diagnose common Cog setup issues, check configuration, and verify that everything is working correctly. Run cog doctor to validate your environment. (#2923)

Improvements

• Static schema generation is now the default. Cog now generates prediction schemas statically from your predictor's type annotations rather than importing and inspecting the Python code at build time. This makes builds faster and more reliable. Use COG_LEGACY_SCHEMA=1 to opt out if you encounter issues. (#2950)
• Test harness improvements. The Cog integration test harness now runs tests in parallel and provides better error reporting. (#2944)

Bug fixes

• Separate-weights builds with r8.im image names work correctly. Schema validation no longer fails when building with separate weights and using r8.im/... image names. (#2954)
• Static schema generation handles more edge cases. Fixed issues with certain type annotation patterns in static schema generation. (#2948)
• Secret = Input(default=None) is treated as optional. Secret inputs with None defaults are now correctly identified as optional in the generated schema. (#2949)